§ 718 xfi aj Petrography of Some Granitic Bodies in the Northern White Mountains, California-Nevada GEOLOGICAL SURVEY PROFESSIONAL PAPER 775 DOCUMENTS Deparment (A NjA G Bishop \ Base from U.S. Geological Survey 1:250,000 Mariposa, 1957-64; Goldfield, 1954-62; Walker Lake, 1957-66 o 5 10 MILES FIGURE 1.-Northern White Mountains, California-Nevada. DESCRIPTION OF GRANITIC UNITS 3 1964; Bateman, 1965; Moore, 1963). Reconnaissance studies in Nevada, immediately north and east of the White Mountains, led to similar conclusions (Ross, 1961; Albers, 1964). The northern White Mountains lay virtually untouched, chiefly because of their rugged terrain and the lack of base maps, although Ross (1961) and Albers and Stewart (1965) worked along their edges. The first modern studies of the granitic basement of the northern White Mountains were begun in 1950 by D. O. Emerson, who made a petrographic study of the granitic masses of the Mount Barcroft quadrangle (immediately east of the White Mountain Peak quadrangle). Emerson's (1959, 1966) work showed that Anderson had included several discrete plutonic units as well as metamorphic rocks in his Pelli- sier Granite and that the granitic rocks of the quad- rangle are predominantly intrusive (Emerson, 1966, p. 146-147). Subsequent geologic mapping of the Mount Barcroft quadrangle by Krauskopf (1968) cor- EXPLANATION o 0 N 0 Volcanic and sedimentary 5 rocks 0 M 0 o Quartz monzonite of g 5 A33 - %/\/Q it Boundary Peak C % 6 Other granitic E] M g: E rocks A - K Quartz monzonite Granodiorite of Diorite of U’ o and granite of - Mount Barcroft Queen 3 ¢ Pellisier Flats Canyon nfe) Eo E > Granodiorite of the Benton Range P < kits < +108" % * |v iA Metavoleanic rocks metasedimentary rocks PERMIAN (7), TRIASSIC, AND JURASSIC Metamorphic rocks of probable Paleozoic age Sedimentary rocks; in part metamorphosed Contact LATE PRECAMBRIAN CAMBRIAN, AND ORDOVICIAN Fault roborated Emerson's findings, as did detailed studies of the quartz monzonite of Boundary Peak by Harris (1967). The dominantly granitic terrane of the west slope of the White Mountains, however, was still virtually unmapped, requiring a combination hard-rock geologist and mountaineer. In 1964 Dwight Crowder was per- suaded to bring his ice ax from his beloved Cascade Mountains to the White Mountains, where he pro- ceeded to map and study the rocks on this rugged mountain front. The work was halted by his death in 1970. This report records some of Crowder's findings and helps refute the concept that the White Mountains are a locale of large-scale granitization. The petrography and chemistry of these rocks are stressed in this report, which does not deal with the wallrocks or other aspects of the regional geology. For further information on the regional geology, the reader is referred to the following geologic quadrangle maps and accompanying explanatory texts: White Mountain Peak (Crowder and Sheridan, 1973), Benton (Crowder, Robinson, and Harris, 1973), Mount Barcroft (Kraus- kopf, 1971), Davis Mountain (Robinson and Crowder, 1973), and Casa Diablo Mountain (Rinehart and Ross, 1957). On both the White Mountain Peak and Benton maps, the term "adamellite" has been used, but it has been changed in this report to the equivalent term "quartz monzonite" for the comparable units, as that term is more commonly used in this region. Sample localities for modes and chemically analyzed rocks are shown in figure 3. Potassium-argon radio- metric age dates for these granitic rocks are discussed in a report by Crowder, McKee, Ross, and Krauskopf (1973). The quartz monzonite of Boundary Peak is probably Late Cretaceous, and the Mount Barcroft and Pellisier Flats units are probably Triassic or Jurassic, although there are problems in dating these two altered granitic units. The granodiorite of the Benton Range is probably Triassic. DESCRIPTION OF GRANITIC UNITS GRANODIORITE OF THE BENTON RANGE GEOLOGIC SETTING AND GENERAL DESCRIPTION Less than 10 square miles of the granodiorite of the Benton Range is exposed in the southern part of Blind Spring Hill (frontispiece). These rocks are physically separate from, but texturally and mineralogically sim- ilar to, the granodiorite of the Benton Range abun- dantly exposed in the adjoining Casa Diablo Mountain quadrangle (Rinehart and Ross, 1957). Similar rocks 4 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA FigurE 2.-Contact of light-colored quartz monzonite of Boundary Peak with the dark-colored quartz monzonite and granite of Pellisier Flats. Taken from U.S. Highway 6; view southeastward into the White Mountains. High point on the skyline is Boundary Peak, 13,140 feet, the highest point in Nevada, The sage-covered valley floor is about 6,000 feet above sea level. are present to the northwest in the Glass Mountain TABLE 1.-Modes of ggftwgigritfi of éhfi Benton Range qpaQrapgle, bqt their extent is not known. Thés grano- J Toff]. not 3] diorite is a major basement rock type underlying more : than 200 square miles and possibly has a much greater Sample _ Plagioclase Quartz Biotite Hornblende _ area, as judged by probably correlative rocks in the 18 33 é? é ‘12 32‘s) Sierra Nevada (Rinehart and Ross, 1964, p. 47). Near 40 34 15 1 10 d. the north end of Blind Spring Hill, it is intruded by the g?) if; 2g few 43 4220 7 5164 27°45' 0 2 4 MILES Lik. £2 2 460 (Float) 54 37°30" {- FIGURE 3.-Location of modally and chemically analyzed specimens. DESCRIPTION OF GRANITIC UNITS 7 2 or 3 feet across, are widespread and locally common, but in general are much less common than in Sierra Nevada granitic rocks of equivalent composition. __ The most noteworthy feature of hand specimens of this rock is the abundance of K-feldspar. Casual field observation suggests that the rock is a granodiorite; however, close observation reveals abundant pinkish feldspar in many specimens, and staining shows that K-feldspar predominates. The modes (fig. 8; table 3) show a field that blankets the quartz monzonite range and extends across much of the granite field. Because of the large number of points that fall within the granite field, the modal field is unusual in comparison with that of most other granitic bodies of the Sierra Nevada and the White and Inyo Mountains. EXPLANATION as Quartz mongonite Granodiorite - Quartz monzonite and granite of of Mount of Boundary Peak Pellisier Flats Barcroft Overprint indicates albitized mized metavolcanic and Pellisier rocks +04 + +o +o+ +o+ + +o +o+ Granodiorite of the Diorite complex Benton Range Contact Fault SAMPLE LOCALITIES Numbers are keyed to tables in text 128 0 New mode 1-7, diorite complex; 10-17, quartz monzonite of Boundary Peak; 20-25, granodiorite of the Benton Range; 30-62, gramodiorite of Mount Barcroft; 101-165, quartz monzonite and granite of Pellisier Flats »H-20 Mode from another source Letter prefix keyed to reference list: E, Emerson (1959); H, Harris (1967); R, Rinehart and Ross (1969, p. 43); M, Ross (1961, p. 34) p16 Chemically analyzed sample Three specimens from Boundary Peak (in parentheses-116, 214, and 241) do not have modal analyses FIGURE 4.-Granodiorite of the Benton Range. Abundant euhedral K-feldspar phenocrysts, small dioritic inclusions, and euhedral hornblende crystals are visible. Quarter for scale. EXPLANATION 21 o New mode LU Mode from Rinehart and Ross (1964, p. 43) Hornblende H3:1 11 Biotite 1: ornblende-biotite rage faf Plagioclase \| ig K-feldspar FIGURE 5.-Modal distribution of quartz, K-feldspar, and plagioclase of the granodiorite of the Benton Range. 8 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA FIGURE 6.-Photomicrograph of fine-grained "aplitic' ground- mass of specimen 25 from the granodiorite of the Benton Range. 37°45" ® 7Z [o) m 12 10 EXPLANATION 4 as Biotite + hornblende, y Samfile _18 in percent i "'"»°s3 4.0 Ratio of hornblende gre to biotite Sample locality Open circle, new mode; solid circle, mode from Rinehart and Ross (1964, p. 43) § -_ FicurE 7.-Sample localities, dark-mineral content, and ratio of hornblende to biotite in specimens in the granodiorite of the Benton Range. Quartz EXPLANATION 0 Normal gray facies o Coarse felsic facies U Other Contain abundant chessboard albite face: Plagioclase K-feldspar FIGURE 8.-Modal distribution of quartz, K-feldspar, and plagioclase in the quartz monzonite and granite of Pellisier Flats. TABLE 3.-Modes of quartz monzonite and granite of Pellisier Flats [n.d.=not determined] Mafic minerals Specific P K- Sample Plagioclase feldspar Quartz m gravity Normal phase 32 30 15 18 5 2.170 41 22 17 19 1 2.69 31 38 17 5 '8 2.68 40 37 12 1+ 10 2.65 33 29 14 20 4 2.68 35 42 15 <1 8 2.64 41 25 12 22 2.173 37 25 17 18 8 2.178 35 35 18 9 d 2.68 41 24 17 9 9 2.70 30 30 17 28 2.170 20 44 28 13 2.62 22 56 11 10 1 2.62 20 45 27. 8 2.62 14 52 29 5 2.63 24 45 19 12 2.64 21 46 8 19 2.63 28 50 15 12 2.62 16 46 17 21 nd. 24 47 11 18 2.68 26 46 11 17 2.67 28 39 8 25 2.69 13 49 20 18 2.65 18 62 12 8 2.62 13 58 8 21 2.69 21 48 9 22 2.65 30 44 10 16 2.65 24 39 12 25 2.170 87 29 16 10 8 2.170 39 27 17 11 '5 2.170 28 40 15 15 2 2.66 DESCRIPTION OF GRANITIC UNITS ] TABLE 3.-Modes of quartz monzonite and granite of Pellisier Flats-Continued Mafic minerals Specific Sample Plagioclase felcfipar Quartz m gravity Coarse phase 38 35 28 4 2.63 39 28 21 12 2.66 24 47 22 T 2.62 22 49 22 7 <1 2.62 25 42 24 9 2.64 34 35 22 9 2.64 27 46 22 5 2.62 36 38 18 8 2.65 29 39 20 12 2.65 23 40 28 9 2.64 20 57 20 3 2.64 12 61 24 3 2.60 37 35 21 7 2.62 35 32 26 7 2.63 36 32 29 3 2.62 40 28 28 4 2.64 26 45 21 8 2.62 29 44 20 7 2.62 13 55 29 3 n.d. 15 61 15 9 2.63 16 46 17 21 2.60 25 46 20 9 2.66 29 41 22 8 2.63 Other samples 65 1 18 16 2.64 40 33 10 17 2.71 50 13 17 19 1 2.170 32 32 19 17 2.67 39 32 9 1 19 2.173 30 33 18 19 2.69 68 0 25 7 2.60 22 42 30 6 es n cooke 71 0 29 0 2.60 22 49 28 6 2.62 8 57 30 *'5 2.62 8 61 29 2 2.63 23 40 19 18. 0 isan a Rocks of Harris (1967) 43 28 27 esen y e T L 53 15 29 O 0 .> 0 Lig 39 29 26 6 - 3. n caer 35 34 19 12" / =o 54 15 24 T. SLT Pr vive 40 27 14 19 ® "o> " Lang H-10. 39 28 13 20 ®.. ss. 18. o H-11. 37 40 13 10 - - }}. .s. H-21. 28 49 22 1.9.00 e H-31. 47 29 21 O L sarl nl anes Rocks of Ross (1961) M-30.......... 30 39 23 5. tian cg. M-31.......... 38 24 21 $7.03 01.0 Wl 11 percent metallic opaque minerals and sphene. *Albite granite (type 1). 'Albitized leucocratic Pellisier Flats (type 3). 'Altered to chlorite. A coarser grained more felsic central core facies of the Pellisier Flats unit can be distinguished in the hand specimens collected. In the area of Mount Dubois, it forms a northeast-trending belt (fig. 9) that contains more quartz and fewer mafic minerals than the normal part of the Pellisier Flats unit. Both facies average on the granite side of the quartz monzonite field and have similar amounts of plagioclase and K-feldspar (fig. 8). The coarser facies was not mapped in the field, which suggests it is not an obviously separate intrusion. More- over, outcrops of the Pellisier Flats unit north of the quartz monzonite Boundary Peak contain possibly transitional rocks that are coarser than the normal part of the Pellisier but contain more dark minerals than the coarser facies. Some rocks south of the quartz monzo- nite of Boundary Peak, as well as rocks tentatively assigned to the coarser facies west of this pluton, may be transitional. The dull-gray rock probably is normal Pellisier that grades to a coarser more felsic central core facies that crystallized last. On the other hand, the coarse felsic facies may represent nearly pure Pellisier, and the dull-gray Pellisier may be a contaminated altered variant as in the Pat Keyes pluton in the Inyo Mountains to the south (Ross, 1969, p. 11). The virtual absence of hornblende in the coarser facies, however, suggests that the dull-gray rock is typical of the Pelli- sier Flats unit. MICROSCOPIC DESCRIPTION Biotite occurs in shreds, slivers, and irregular aggre- gates or clots and is liberally sprinkled through altered plagioclase in these rocks. The distinctive clots seen in hand specimen are aggregates of biotite, metallic opaque minerals, sphene, and epidote. The shape of some biotite aggregates suggests pseudomorphs after hornblende (fig. 10). The biotite is rather uniformly pleochroic from X=grayish yellow or grayish orange to Z=light olive or light olive brown. Plagioclase is thinly twinned and commonly is richly peppered with sericite, epidote-zoisite, biotite, and some calcite. The pervasive saussuritization of what presumably was intermediate plagioclase has been very thorough, for all the plagioclase now seems to be albite (or oligoclase). Thin-section study of the plagioclase was supplemented by limited X-ray diffraction studies. The anorthite content of three specimens from the coarse felsic facies was about An,;, although the pat- terns were somewhat irregular. Plagioclase from three typical rocks of the gray normal facies from the Benton quadrangle north of the coarse felsic facies showed Any,, An,, and An,. These specimens probably are representative of the unalbitized parts of the Pellisier Flats unit. Four specimens from the gray normal facies of the Pellisier Flats unit south of the coarse felsic facies were picked; the specimens had intensely altered plagioclase, but no chessboard albite, and looked like dark normal rocks of the Pellisier Flats unit. These 10 _ PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA 118°30' li8"i95' \ I I Boundary Peak] MiB I mn 1 IN fl '//\/ ® Float 37°45! |- BENTON QUADRANGLE WHITE MOUNTAIN PEAK QUADRANGLE EXPLANATION Sg - [K] Coarse felsic facies Normal gray facies Quartz monzonite and granite of Pellisier Flats & | y' | -% $», o" g Albitized mixed metavolcanic and granitic rocks (1) Medium-to coarse-grained quartz-albite rocks (2) Albitized metavoleanic rocks (3) Albite granite with abundant K-feldspar C Hornblende-bearing specimen ) White Mountain Float /, Peak Ratio of plagioclase to K-feldspar 25 Contour showing quartz content, in percent Contour interval 5 percent 0 2 4 MILES bars L cnd dines 1a rsd FIGURE 9.-Sample localities in the quartz monzonite and granite of Pellisier Flats and related albitized rocks. DESCRIPTION OF GRANITIC UNITS 11 FIGURE 10.-Photomicrograph of aggregate of small biotite flakes (bi) and magnetite grains (mgt) that probably pseudo- morphs a hornblende crystal in quartz monzonite and granite of Pellisier Flats. rocks all showed X-ray diffraction patterns that suggest An,-;, but the patterns were by no means conclusive for some specimens. The alteration products may mask the plagioclase peaks, or the alteration-product-soaked plagioclase may give weaker-than-normal peaks. Never- theless, the plagioclase is probably sodic and probably albite in much of the area south of the coarse felsic facies. K-feldspar is dominant in most specimens, ranging from small interstitial grains to large irregular to sub- hedral crystals. Some is distinctly grid twinned; more characteristic is splotchy irregular perthite in which finely twinned albite is locally distinct. Quartz, though in part in fairly normal irregular crystals that show undulatory extinction and rather normal mosaicking, is typically in granular almost horn- felsic aggregates. The overall appearance is one of a metamorphic fabric, not a cataclastic one. Anderson (1934, p. 185) noted this feature and suggested the term "pseudo-cataclastic' to identify it; he associated the texture with replacement. Hornblende is rare south of the coarser facies (fig. 9) but widespread north of the coarser facies and even dominant in some specimens (table 1). In some of the northern rocks, hornblende is in discrete subhedral crystals, but more commonly it is intergrown in clusters with fine-grained aggregates of biotite, metallic opaque minerals, and sphene. Although hornblende is rare in the southern rocks, the presence of scattered grains, as well as pseudomorphs after hornblende, suggests that the paucity of hornblende reflects a secondary effect related to alteration of the rocks, not a primary differ- ence in the mineralogy. The hornblende is pleochroic from X=moderate greenish yellow and Y=grayish to dark yellowish green, to Z=various shades of blue green, yellowish green, and moderate green. Metallic opaque minerals present are sphene, apatite, and, less commonly, zircon. Sphene is abundant as irregular inasses in some rocks, and only rarely is in euhedral crystals. MIXED METAVOLCANIC AND GRANITIC ROCKS An "enclave" about 10 square miles in area has been called "mixed metavolcanic and granitic rocks" on the White Mountain Peak geologic map (Crowder and Sheridan, 1973). These rocks, exposed from Lone Tree Canyon north for several miles, were first thought to be a separate felsic intrusive. In fact, many of the outcrops are light colored and superficially resemble aplite and alaskite. Within this outcrop are patches and intru- sive (?) areas of the Pellisier Flats unit. The "enclave" also contains abundant metavolcanic rocks with clearly recognizable porphyritic volcanic textures. It is here proposed that the "enclave" is an area of metavolcanic rocks that has been extensively intruded by the Pellisier Flats unit and, even more significant, has been drenched in the solutions that altered and albitized the southern part of the Pellisier Flats unit. In fact, some of the kinds of intensely albitized rocks com- mon in the "enclave" are found some distance away within outcrops of the Pellisier Flats unit (fig. 9). Three main rock types make up the body of mixed metavolcanic and granitic rocks. The most abundant (judging by collected specimens) is a medium- to coarse-grained rock that looks alaskitic in hand speci- men, but is composed almost entirely of albite and quartz. This rock is generally fresh looking in thin sec- tion and features cleanly twinned chessboard albite and thin discontinuous twins that seem to be a variant of chessboard twinning (fig. 11). It has no K-feldspar and virtually no dark minerals. Some specimens of the Pelli- sier Flats unit appear to be transitional to the albite- quartz rocks (fig. 12), which may have originally been part of the Pellisier Flats unit. The next most abundant rock type is metavolcanic rock with striking porphyritic texture and a grano- blastic groundmass. Some phenocrysts as much as a few millimeters across are euhedral; they are now mostly chessboard albite to finely, discontinuously twinned albite. The fine-grained to dense groundmass is composed dominantly of quartz and albite; K-feld- spar is abundant in the groundmass of some specimens. Flow structure is preserved in part, and some specimens 12 - PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA FIGURE 11.-Photomicrographs of fresh secondary albite (ab) with discontinuous and chessboard twinning in intensively albitized rocks of the Pellisier Flats unit. A, discontinuous twinning; B, chessboard twinning. look tuffaceous. The groundmass of some still has a felty aspect. There can be little doubt that these rocks were originally volcanic. In the field, some of these rocks are easily confused with quartzite or aplite, par- ticularly where the original volcanic texture is subtle or absent. Abundance of aplite locally in this "enclave" of mixed rocks further complicates the problem of field identification. The other common rock type in the mixed area is albite granite with abundant K-feldspar. Its texture is granitic, but dark minerals are commonly minor or absent. Some specimens are aplitic to alaskitic, but have some chessboard-twinned albite. In these rocks, much of the albite is cloudy and only incompletely altered from the originally more calcic plagioclase. These rocks may represent a transitional stage on the way to albite-quartz rocks. FIGURE 12.-Photomicrographs of fresh secondary albite and saussuritized original plagioclase from same specimen, Pelli- sier Flats unit. A, fresh secondary albite showing chessboard and discontinuous twinning; B, saussuritized plagioclase crystal liberally sprinkled with biotite shreds and flakes. The K-feldspar-bearing albite granites and the me- dium- to coarse-grained albite-quartz rocks occur not only in the "enclave" but also in the main mass of the Pellisier Flats unit, where they appear to be transi- tional to normal rocks of the Pellisier Flats unit, sug- gesting that these albite-rich rocks are variously altered Pellisier rocks mixed in with the metavolcanic rocks. DIORITE COMPLEX OF QUEEN CANYON Along the south side of Queen Canyon on the north side of the quartz monzonite of Boundary Peak is a 4-mile-long belt of outcrop of various dioritic rocks mixed with felsic rocks (fig. 3; table 4) that may be related to the Pellisier Flats unit. Although some Pelli- sier-rocks are present, the complex also contains a variety of hornblende diorite and related rock types DESCRIPTION OF GRANITIC UNITS 13 TABLE 4.-Modes of diorite complex of Queen Canyon [X indicates mineral present, but no mode run] Sample Plagioclase K-feldspar Quartz - Biotite Hornblende 21:23:11? 50 + 45+ 2.96 60+ <5 40+ 2.87 60 + 40+ 2.87 .. (similar to sample 5) .... ee Ha io Mea 2.170 36 29 11 11 13 2.172 X X X MoS 2.66 50+ 5-10 _ 40-50 2.89 'Contains about 5 percent epidote in discrete crystals. that make it distinctive from the main mass of the Pellisier Flats unit. Aplite, alaskite, pegmatite, and other felsic rocks make up as much as 50 percent of the complex. Presumably, these felsic types are largely offshoots of the quartz monzonite of Boundary Peak. In general, this complex contains dioritic rocks that are probably somewhat older than the Pellisier Flats unit, as well as Pellisier-like rocks and younger felsic rocks that are probably part of the quartz monzonite of Boundary Peak. Hornblende diorites of various grain sizes probably are the most abundant rock types in the complex. They range from fine-grained aplitic or granoblastic rocks to irregular-textured coarse rocks characterized by large hornblende crystals. The same kinds of hornblende diorite are relatively common in small masses in the granitic terranes of this region and are abundant in the Casa Diablo Mountain quadrangle to the west (Rinehart and Ross, 1957). These diorites are com- posed chiefly of about equal amounts of andesine and hornblende that is pleochroic from X=moderate green- ish yellow and Y=various shades of olive and olive brown to Z=moderate to brilliant green. Small amounts of K-feldspar, quartz, and biotite (pleochroic from X=grayish yellow to Z=-=moderate reddish brown) are found in some specimens. Sphene is a rela- tively abundant accessory mineral; metallic opaque minerals are surprisingly rare or absent in most of these rocks. The diorite appears to grade into medium-gray medium-grained quartz monzonite containing biotite and hornblende in about equal amounts. The biotite is pleochroic in shades of olive and olive brown, and the hornblende has the same pleochroism as in the diorite. In these rocks, the plagioclase appears to be oligoclase. The quartz monzonite also has abundant accessory sphene; metallic opaque minerals are rare or absent. In addition to hornblende diorite and related rocks, the diorite complex contains granoblastic to gneissic rocks that have biotite but no hornblende and that are characterized by large pinkish K-feldspar crystals as much as 15 mm long. These rocks with strongly chlori- tized biotite do contain metallic opaque minerals, both as small particles in the chlorite and as discrete large crystals. The felsic members of the complex are aplite, alaskite, simple pegmatite, and coarse-grained biotite quartz monzonite that probably is related to the quartz monzonite of Boundary Peak. GRANODIORITE OF MOUNT BARCROFT GEOLOGIC SETTING AND GENERAL DESCRIPTION Outcrops of the Mount Barcroft unit extend (fig. 13) over an area of about 15 square miles in the southeast- ern part of the White Mountain Peak 15-minute quad- rangle. They mark a profound structural break between Cambrian sedimentary rocks on the south and a mixed sequence of volcanic and sedimentary rocks of probable Mesozoic or late Paleozoic age on the north. The blunt dike-shaped mass extends northeastward into the Mount Barcroft quadrangle, where it covers an addi- tional 10 square miles (Krauskopf, 1971). A 5-square mile mass of correlative rocks (Emerson, 1966; Kraus- kopf, 1971) is exposed about 2 miles farther east along the same trend as the main mass. The two masses are separated by younger intrusive rocks. The profound structural break appears to swing north in the Mount Barcroft quadrangle, whereas the trend shown by the two masses of the Mount Barcroft unit cuts across the trend to the northeast. Nevertheless, the western mass of the granodiorite of Mount Barcroft probably is con- trolled by this major structural break. The Mount Barcroft unit is made up of medium-gray medium-grained rock that is generally equigranular; rare poikilitic K-feldspar crystals are as large as 10 mm. Along the north margin of the mass, the rocks are dis- tinctly coarser grained than elsewhere. Fresh rocks are dark colored not only because of the abundance of dark minerals but because of dark-appearing feldspar. Some K-feldspar is a purplish pink. Quartz is not readily visible in most hand specimens. Dark minerals occur mostly as iregular aggregates that give a splotchy, messy texture to the rock; only locally are biotite and hornblende in discrete crystals. In some rocks, the dark minerals in part form distinctive rounded clots a few millimeters across. Dark rounded dioritic inclusions generally only a few inches across but as large as 2 feet in largest dimension are widely distributed and locally abundant, though in general much less abundant than one would expect in a granitic rock that contains 20-25 percent dark minerals-at least in the region of the Sierra Nevada batholith. The relative abundance of K-feldspar in these rocks (most modes plot in the quartz monzonite field) is also surprising for rocks this dark. 14 - PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA VFIGURE 13.—Typica1 bouldery outcrop of granodiorite of Mount Barcroft. EXPLANATION lel New mode 6 A o“ Modes from Emerson & (1959, 1966) QC? Triangle , rock from eastern g mass & Biotite Hornblende 50 3:1 (T I. is (plus clinopyroxene) Hornblende-biotite ratio Quartz monzonite Overall average Average \ Syenodiorite Monzonite 35 65 65 35 16 K-feldspar Plagi - oclase FIGURE 14.-Modal distribution of quartz, K-feldspar, and plagioclase in samples from the granodiorite of Mount Barcroft. The modes (fig. 14; tables 5, 6) show a considerable spread but have a general clustering of most points in the quartz monzonite field. The tailing off of the field to quartz diorite in part represents plagioclase-rich rocks in the northeastern part of the western mass, but much of the variation has no obvious trend. Emerson (1959, p. 94) noted that the K-feldspar of these quartz diorite specimens has low triclinicity and a low albite to orthoclase ratio relative to the K-feldspar in other samples of the mass. The granodiorite of Mount Bar- croft is quartz poor relative to most other granitic rocks in this region, and a number of points plot in the mon- zonite and syenodiorite fields. In general, the rocks along the southeastern side of the western mass and the western part of the eastern mass are slightly richer in quartz. The somber gray appearance and the fuzzy, splotchy look of the dark minerals are the most distinctive features of this mass in outcrop. MICROSCOPIC DESCRIPTION Plagioclase is generally well formed and well twinned; it ranges from fresh to highly altered grains rich in DESCRIPTION OF GRANITIC UNITS 15 TABLE 5.-Modes of granodiorite of Mount Barcroft Mafic minerals Sample Plagioclase K-feldspar Quartz Metallic 3 Specific gravity Biotite Hornblende Clinopyroxene opaque Undivided minerals 42 28 8 22 2.16 34 38 8 20 siva 2.74 38 22 6 24 8 2.178 48 25 4 15 9 2 2 2.16 48 26 9 22 2.16 32 37 10 10 8 1 2.172 35 39 7 19 2.172 50 15 7. nere 28 2.179 33 32 6 12 16 1 2.74 46 7 5 42 2.83 49 11 6 <1 84 2.83 39 30 8 <1 28 2.74 34 36 16 8 5 <1 1 2.72 37 29 9 eeu 25 2.16 31 87 12 10 7 '2 1 2.74 42 28 7 15 ¥ <1 1 2.73 39 25 12 15 & <1 1 2.73 46 12 10 15 16 <1 1 2.18 44 29 8 12 7. 1 2.178 44 13 4 39 2.85 36 31 8 25 2.16 41 34 10 15 2.74 29 43 15 8 4 1 2.70 36 36 12 16 2.74 37 33 11 11 7 1 2.78 39 29 8 24 2.15 36 28 19 17 2.74 35 33 10 22 2.13 37 29 11 28 2.172 37 82 10 18 8 2.71 48 13 4 25 10 2.82 38 24 7 26 5 2.178 47 16 4 *38 2.82 39 27 10 16 7 1+ 25 2.15 24 'Trace of orthopyroxene *Contains clinopyroxene. TABLE 6.-Modes of granodiorite of Mount Barcroft by Emerson (1959, p. 58, 95)" Sample Plagioclase _ K-feldspar __ Quartz Biotite - Hornblende - AfMEOI Chlorite mnarels 42.7 21.9 13.6 9.8 9.9 0.6 0.6 09: _. ~A... 35.1 24.2 13.9 12.9 11.6 .6 .6 LL _ ssc .... 40.4 25.9 8.6 12.5 11.1 AHF C obie 1.1" a 00> k.. 50.4 18.6 5.4 19.5 3.6 1.4 iA LO. ..> 56.3 7.0 12.8 21.7 .6 189 }} s (plate ant a 41.0 24.7 5.5 10.1 16.3 9 .5 1.0. ¢ :. his 46.1 18.1 5.4 12.1 16.5 ree ta . 80 lias 40.3 18.9 8.0 17.9 13.9 $o p o oo Woke. «TI ts 36.2 25.1 17.0 14.5 5.7 ifa one 19 . c lode. 39.8 22.2 14.2 10.6 "10.0 T e as ail, 30:8... l... 30.7 30.3 17.3 9.2 '6.5 '4.4 .8 »B s "...-- 44.1 14.6 8.9 22.6 8.8 19k . Astove STs N 2 Mavis 38.4 20.4 4.2 12.9 ad cst s anes e o o erp rind c ena 1.2 45.8 12.9 5.9 16.7 LTB vial ot an Phi t (man 1.5 42.9 4.4 7.5 16.2 10 ea t i 0 0 oon . mol 1.1 55.8 3.3 12.1 9.7 L9 s rts a n N U . 1. o, 2.8 529. .s ) in. 9.6 8.0 PIM:. Ls anes 00 T O nc " 8 35.3 22.6 15.9 18.4 8.9 : geri 3. p * ease A . 0 | - oils 2.5 37.6 81.5 14.6 8.1 ry dran nce o po aaa a a o 2.5 39.7 25.7 13.1 11.4 ye taco o" e a arr a o ee 2.8 35.9 31.8 12.9 4.9 NLB ' n a o 0 - (.- Wever 3.0 42.2 19.2 10.8 13.3 12.4 2.1 'About 20 percent of sections studied contain augite along with hornblende (Emerson, 1959, p. 60). *Predominantly augite. "1 percent hypersthene, abundant augite, less than 1 percent hornblende. «Predominantly secondary pyrite. 16 - PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA sericite and epidote-zoisite and is liberally sprinkled with biotite flakes (fig. 15). Zoning, in part oscillatory, is mostly in the andesine range; however, some cores are sodic labradorite, and some rims lap over to oligo- clase. K-feldspar is generally in irregular interstitial grains of various sizes that grade up to poikilitic crystals several millimeters in diameter than engulf all other minerals in the rock. Quartz is mostly in thin vermicular but in part straight-sided crystals (fig. 16). All the quartz is some- what strained and shows a range from grains with undu- FIGURE 15.-Photomicrograph of plagioclase crystal in the granodiorite of Mount Barcroft flooded with sericite, epidote- zoisite, and biotite. FIGURE 16.-Photomicrograph of distinctive interstitial quartz in the granodiorite of Mount Barcroft. latory extinction through mosaic grains with sutured contacts to granulated and slivered grains. The dark minerals show the irregular splotchy nature noted in hand specimen. Biotite is mostly in ragged to slivery patches that are pleochroic from grayish orange to various shades of olive and brown. Alteration to chlorite is common. Many crystals that appear unaltered have trains of sphene droplets concentrated on cleavages; needles that may be rutile are common in the biotite in three directions 120° apart. Much bio- tite is in greenish aggregates with much epidote and chlorite; some of these aggregates contain remnants of the olive to brown biotite. Hornblende remnants in some indicate they were probably originally horn- blende, and the shape of similar biotite aggregates strongly suggests they also were once hornblende. Hornblende occurs most commonly in ragged clusters with biotite, sphene, apatite, and metallic opaque min- erals; rarely, hornblende is found in discrete nearly sub- hedral crystals. Cores of some hornblende crystals contain remnants of clinopyroxene that are in part iron stained, accounting for the reddish spots and cores seen in hornblende in hand specimen. One specimen contains orthopyroxene (?) in a hornblende crystal. Fresh horn- blende is green and has the following pleochroism: X=moderate greenish yellow, Y¥-=light olive, and Z=light olive to grayish green and less commonly mod- erate to dark yellowish green. The shredded aggregates of biotite that are in part pseudomorphs after hornblende, the overall messy appearance of both hornblende and biotite, and the small dark clots, dominantly biotite (fig. 17), together give some of these rocks a megascopic resemblance to some of the rock of the Pellisier Flats unit. Although FIGURE 17.-Photomicrograph of irregular aggregate of biotite, hornblende, and magnetite in granodiorite of Mount Barcroft. DESCRIPTION OF GRANITIC UNITS 17 there are significant petrographic differences between the two masses and they are definitely not correlative, the similarities of their dark minerals suggest that both masses have undergone similar alteration. The Mount Barcroft unit was less affected, for most specimens still bear hornblende; although the plagioclase is somewhat « altered, the average specimen is generally more calcic than the rocks in the Pellisier Flats unit. Metallic opaque minerals are abundant and are most commonly associated with the dark mineral clusters. Well-formed crystals of apatite and irregular grains of sphene are widespread. Allanite and zircon are present but rare. Bluish pleochroic tourmaline is widely scattered in trace amounts. QUARTZ MONZONITE OF BOUNDARY PEAK GEOLOGIC SETTING AND GENERAL DESCRIPTION The Boundary Peak unit crops out over some 25 square miles in the northern White Mountains. The mass underlies some very rugged terrain, culminating at 13,140 feet elevation in Boundary Peak. The daz- zling white outcrops led Harris (1967) to liken the Boundary Peak unit to "a shining white fortress set in the somber colored northern White Mountains," an apt description of this vivid contrast (fig. 1). The quartz monzonite of Boundary Peak looks in gross aspect like a great dike whose west-northwest trend sharply cuts across the dominant, more northerly, structural grain of the region. Harris (1967) believed that the Boundary Peak unit is somewhat sheetlike and that it rose from a root zone near the west limit of present outcrops, then spread eastward. The gently dipping roof of granitic and metamorphic rocks cer- tainly suggests that the Boundary Peak unit might be tabular, but this cannot be determined, as the lower contact is not exposed. The Boundary Peak unit is medium to coarse grained and light gray to dazzling white in outcrop but in part weathers to various shades of tan and buff. In many fresh outcrops, pinkish K-feldspar is easily distin- guished from white plagioclase. Coarse masses of clear quartz are evident, and scattered wisps and flakes of biotite are present. Much of the rock, particularly along the west side of the outcrop area, is foliated to gneissic. Where best developed, this foliation is shown by strung- out biotite that gives the rocks an anastomosing struc- ture. Harris (1967) noted that in some of the western outcrops, the quartz grains are sheared into subparallel bands. The granitic rock is remarkably uniform in appear- ance, and the compositional homogeneity is shown by the compactness of the modal field in figure 18. (See also tables 7 and 8.) The ratio of plagioclase to K-feld- spar is somewhat higher along the west side of the mass, Quartz EXPLANATION m New mode ® Mode from Harris (1967) 50 { Plagi- 10 oclase 90 \ 3a g? K-feldspar FicurE 18.-Modal distribution of quartz, K-feldspar, and plagioclase in samples from quartz monzonite of Boundary Peak. which is also slightly lower in quartz, but the differences are not great. Aplite and pegmatite dikes are surpris- ingly rare. Harris (1967) noted them at only one locality about 1 mile northeast of Boundary Peak. Aplite and pegmatite are also present about 2 miles north of Boundary Peak. Inclusions are virtually absent, except for fairly obvious wallrock inclusions from the Pellisier Flats unit and from the diorite complex bodies near contacts. MICROSCOPIC DESCRIPTION The plagioclase ranges from fresh to strongly saus- suritized and is in part oscillatorily zoned. Harris (1967), using the angular separation of the 131-131 reflections by X-ray diffractometer, reported a range of An,, to about An;,. The plagioclase tends to be a bit more felsic to the southeast. Harris also determined the index of refraction of a number of fused glass beads of plagioclase and reported a range of about An,,-Ans;, using the curve of Schairer, Smith, and Chayes (1956, p. 196). Irregular masses of K-feldspar, somewhat less abun- dant than plagioclase, generally are grid twinned and in part perthitic. Harris (1967, p. 47) analyzed several K-feldspars. Those from the quartz monzonite of Boundary Peak show 84-91 percent orthoclase, 8-14 percent albite, and 1-2 percent anorthite. The ortho- clase content is possibly a bit higher in the western, "fat" end of the mass, but very subtly so. Contrastingly, four K-feldspars from the Pellisier Flats unit just north 18 - PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA TABLE 7.-Modes of quartz monzonite of Boundary Peak Mafic minerals F K- Specific Sample Plagioclase feldspar Quartz m ggavity 41 36 20 '3 2.63 41 32 24 3 2.64 48 34 19 4 <1 2.62 45 33 18 4 2.65 40 33 22 '5 2.63 48 31 18 3 <1 2.65 50 30 17 3 <1 2.65 45 30 22 3 <1 2.65 'Also contains 1 percent muscovite. TABLE 8.-Modes ofiquartz monzonite of Boundary Peak by arris (1967, table 1) Sample Plagioclase K-feldspar Quartz Other 43.8 27.6 25.8 42.4 31.2 24.4 39.6 33.2 25.2 42.0 30.1 42.6 31.6 30.5 24.3 31.2 31.2 30.0 wh oe to wa ope we ofm of of ofm p o OU Of sha Qaf ofa G0 sr of afe of ofm CO CO jA ofa whn of of mommwc’MmmmmmofimhMQmfiMMU‘omQP—lmwcfiqwmcommwhh‘fiam ho ho ho 60 ha ho G3 ho ho G3 ho ho GJ ho ho ho ho GJ ho ha ho ho Co G3 G3 Go G3 . & p w 00-10 h O0 o t OH O®-10 ao too tHad® O-~1W bo ho ho ho ho ho ho b ho ho ho ho ho ho ho ho ho ho ho i- ho ho ho ha ho i ho ho ho bo ho ho ho ho ho ho ho ho ho ho ho ho ho ho ho n o ho ho 0 io mho t o ho us i= a 0 is to a ho i= to i= to ih to oo 0 0 t o walsh bo ho ho go ho ho ho G0 G0 ho ho Ot G0 G3 ho wh ho C0 ia C0 C0 C0 it ho C0 60 ho ho i- sa C0 C0 ho 60 ho i ho ho ho ho G0 C0 ho ho ho C0 ho ho bo ID IB iL on oo ho im Oo on ih on & oo ho on ho 1 on o 3 & on in do ho bo do or 1 to & ho on =1 & a ho ih ho os to i ho co ar i & & do of the Boundary Peak unit have 78-81 percent ortho- clase, 17-26 percent albite, and 2-4 percent anorthite. Quartz ranges from irregular masses with undulatory extinction to mosaicked and sutured crystals. In more sheared rocks, the quartz is definitely granulated and slivered into anastomosing trains. Some quartz is sprinkled through the rock in rounded crystals, giving an aplitic look to the rock. Biotite is invariably present in scattered irregular grains. It is pleochroic from X= grayish yellow and grayish orange to Z=light olive to light olive brown. Gray-green to moderate-green horn- blende is present in trace amounts in several specimens. Metallic opaque minerals, sphene, apatite, zircon, and allanite (in part rimmed with epidote) are scattered through the mass. The alteration products chlorite, sericite, and epidote are present in variable amounts. Most thin sections, though structureless, do show some quartz strain and locally have bent and fractured feldspar crystals. Locally rocks of the Boundary Peak unit are foliated and gneissic. Harris (1967, p. 20) noted that deformation was most intense near the western contact and attributed this largely to forcible injection (Harris, 1967, p. 40), speculating that the Boundary Peak unit may have been forcibly emplaced along an early fault zone near its west margin. A rather strong north-trending foliation in the bounding rocks of the Pellisier Flats unit to the west could be a reflec- tion of such a zone of weakness. CHEMICAL RELATIONS During the geologic mapping, Crowder obtained chemical analyses of specimen 44 of the granodiorite of Mount Barcroft, specimens 124 and 134 of the quartz monzonite and granite of Pellisier Flat, and specimens 116, 214, and 241 of the quartz monzonite of Boundary Peak (table 9). Unfortunately, except for specimen 44, thin sections are not available, and the specimens are missing. Owing to fading or illegibility of labels, a num- ber of specimens from Crowder's collection could not be identified and had to be thrown out. Presumably, the missing chemically analyzed specimens were in this group. Nonetheless, it seems worthwhile to record the analyses, even though their petrography is unknown. The remaining five chemical analyses given in table 9 were obtained by Ross from specimens collected for radiometric age dating. The 11 chemical analyses rep- resent a very small and probably unrepresentative sample of the intrusive bodies, as can be seen from figure 3. The study of numerous thin sections indicates that the chemical analyses of the granodiorite of Mount Barcroft probably represent fairly well the rock type of at least the western mass and that those of the quartz monzonite of Boundary Peak probably repre- sent this unit fairly well. The large, variable, and much- altered Pellisier Flats unit, on the other hand, is far less representatively sampled by the four analyses of table 9. We do not know what specimens 124 and 134 repre- sent; their field location suggests they are part of the CHEMICAL RELATIONS 19 TABLE 9.-Chemical analyses of granitic rocks in the northern White Mountains [Chemical analyses by rapid rock method; analysts: P. L. D. Elmore, Lowell Artis, J. L. Glenn, Gillison Chloe, Hezekiah Smith, and James Kelsey. Semiquan- tative spectrographic analyses by Chris Heropoulos. Results are to be identified with geometric brackets whose boundaries are 1.2, 0.83, 0.56, 0.38, 0.26, 0.18, 0.12 .. . , but are reported arbitrarily as midpoints of these brackets, 1, 0.7, 0.5, 0.3, 0.2, 0.15, 0.1 . . . The precision of a reported value is approxi- mately plus or minus one bracket at 68 percent, or two brackets at 95 percent confidence. Looked for, but not found: Ag, As, Au, Bi, Cd, Mo, Pd, Pt, Sb, Sn, Te, U, W, Zn, Ge, Hf, In, Li, Re, Ta, Th, Tl, Pr, Sm, Eu] Granodiorite of Mount Barcroft Quartz monzonite and granite of Pellisier Flats Quartz monzonite of Boundary Peak 44 61 62 124 134 163 165 16 116 214 241 Chemical analyses (weight percent) 62.6 60.1 57.8 70.0 70.0 64.8 66.1 68.7 71.4 12.4 70.4 16.5 17.3 17.1 14.7 15.0 16.4 15.8 16.8 15.4 15.3 15.7 1.9 2.1 2.2 1.4 1.2 1.8 1.5 1.0 87 .82 1.0 3.2 3.6 4.5 1.2 1.1 2.6 2.4 .96 57 A4 42 2.2 2.5 3.4 10 .61 1.6 1.5 43 24 22 .24 3.9 4.6 6.0 1.3 1.2 2.8 8.0 2.4 1.7 1.3 2.0 3.2 8.2 2.9 4.0 3.8 3.1 3.5 4.4 4.3 4.1 4.3 4.4 4.3 3.6 4.7 4.9 5.0 4.6 4.2 3.8 4.0 3.8 0 1.0 1.0 .06 .05 81 .60 135 .03 .08 10 08 .80 .33 A1 <.05 100.02 1 1,500 ~150 10 20 30 15 70 """ 10 15 15 1,000 70 20 2 100 CIPW norms (weight percent) 10.9 9.0 25.4 26.2 15.5 19.1 21.4 28.6 30.6 27.0 351 24112 35:2” £29,171 2?!) 23g 25.0 22.8 23.9 22.9 A + z . 31.7 - 37.5 36.9 35.1 37.0 2&3} Anas 2%.§I}Ams 5.,75An14 5.3}Am 11.5}Anz1 13_8}Amz 11 5}Anzx 7 6}>Arm 6 3}An15 9_2}Amo 6.3 8.6 ATS Tp" 1s -., $8 ~ "1" 3.8 < ATA woe s sins .6 3.8 5.3 A 4 2.6 2.3 -5 (is o heats PO Ges 3.1 8.2 2.1 1.8 1.9 2.2 1.5 1.3 11 .9 ................................................................................ 4 4A 1.5 1.7 .8 .8 1.5 1.2 +6 .3 .3 4 .8 1.0 .3 .3 .6 4 2 A * 2 s f 1.0 1.6 A .8 1.5 2.0 1.2 a y as Pde t dec cds 1 ced ies ! Cele i dock 119 an a 19 L, al I A1 100.1 100.1 100.0 100.0 100.0 100.0 100.2 100.0 100.1 99.9 Niggli numbers 229.5 204.6 179.5 348.7 355.3 258.0 272.1 317.3 375.6 396.0 361.2 35.6 34.1 31.3 43.2 44.9 38.8 38.3 45.7 47.7 49.3 47.5 27.4 28.6 32.9 15.7 14.0 22.0 22.4 10.3 8.0 7.4 7.1 15.3 16.8 20.0 6.9 6.5 12.0 13.2 11.9 9.6 7.6 11.0 21.1 19.9 15.9 34.3 34.6 27.2 26.1 32.1 34.1 35.7 38.8 42.8 25.0 16.1 j11.7 117.1 49.3 68.0 89.0 136.9 153.2 125.9 .5 a .5 A .5 .5 .5 4 4 A E 4 4 .5 .3 .3 A A .3 £ .2 18 Specific gravity (bulk) 2.174 2.16 2.16 2.62 2.62 2.67 2.67 2.61 n.d. 2.61 2.68 Modes (volume percent) Plagioclase ... 31 38 47 20 20 24 39 50 K-feldspar 37 24 16 44 45 39 27 30 Quartz .... 12 4 23 27 12 17 17 Biotite .... 10 26 13 8 25 11 3 Hornblende . T 5 133 5 <1 Clinopyroxene ...... $2 (s fo rood & Metallic opaque minerals Ms omg s . Roane son is Vi deben onle i 1 'Mixed biotite, hornblende, and clinopyroxene with epidote and chlorite. *Trace of orthopyroxene. Specimen localities (parentheses enclose California Grid System coordinates, zone 4) : 44. T. 4 S., R. 33 E., (2,638,000 E., 391,500 N.), White Mountain Peak quadrangle. 61. Sec. 3, T. 5 S., R. 33 E., (2,628,800 E., 388,000 N.), White Mountain Peak quardangle. 62. Sec. 33, T. 4 S., R. 33 E., (2,627,200 E., 393,800 N.), White Mountain Peak quadrangle. 124. T. 2 S., R. 33 E., (2,627,200 E., 482,000 N.), Benton quadrangle. 134. T. 2 S., R. 33 E., (2,625,000 E., 470,700 N.), Benton quadrangle. 163. (Float) T. 3 S., R. 33 E., (2,623,000 E., 422,700 N.), White Mountain Peak quadrangle. 165. (Float) T. 1 S., R. 32 E., (2,596,300 E., 491,000 N.), Benton quadrangle. 16. (Float) T. 1 S., R. 32 E., (2,596,300 E., 491,000 N.), Benton quadrangle. 116. T. 1 S., R. 33 E., (2,614,500 E., 506,800 N.), Benton quadrangle. 214. T. 2 S., R. 33 E., (2,629,300 E., 489,700 N.), Benton quadrangle. 241. T. 1 S., R. 33 E., (2,629,500 E., 502,600 N.), Benton quadrangle. 20 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA coarse felsic facies, although Crowder's field notes describe both localities as "typical Pellisier." Specimen 163 is typical gray Pellisier with abundant K-feldspar, highly altered plagioclase, shredded scattered biotite, and no hornblende, a composition associated with the area of widespread albitization, and is probably a repre- sentative sample of the Pellisier Flats unit south of the coarse felsic facies. Specimen 165, in contrast, retains original hornblende, has much less altered plagioclase, and is a fair sample of the less altered Pellisier Flats unit north of the coarse felsic facies. Despite the limitations of these chemical data, gen- eralizations can be made about the northern White Mountains granitic rocks. The silica variation diagrams (fig. 19) have remarkably linear plots. If Anderson's analyses (1937) were similarly plotted, they would show wide divergences from the trends of figure 19. The variation diagrams reflect the high K-feldspar content of specimens 124, 134, and 163 of the Pellisier Flats unit by their low CaO content and correspondingly high K,0 content. But as these specimens are not enriched in Na,0, it appears that, even though their plagioclase is strongly altered, they are not strongly albitized, for were they, the NaQ would be enriched, probably at the expense of K0 as well as CaO. The trends of the oxides in the variation diagrams show that CaO is markedly lower and that K0 is markedly higher than in similar plots for other granitic suites (fig. 20). These proportions mean that not only is the Pellisier Flats unit extremely high in K-feldspar, but also the entire granitic suite is rich in K.,0 relative to other granitic suites in the western batholithic belt. Compared with the other granitic suites, the northern White Mountains rocks seem to become relatively enriched in both Na.0 and Al;O; as SiO, increases. The northern White Mountains rocks have a low Peacock index, about 54, which puts them well into the alkali-calcic field (fig. 21). The eastern and central Sierra Nevada granitic rocks have a Peacock index of about 60, the Coast Ranges about 61, the western Sierra about 63, the Southern California batholith about 65, and the Klamath Mountains about 63 (Ross, 1972; P. E. Hotz, oral commun., 1971). It appears that the entire northern White Mountains suite is rich in alkalis and poor in lime, apparently reflecting a regional trend rather than a local alteration effect. Bateman and Dodge (1970) noted that K0 increases eastward across the Sierra Nevada batholith and that CaO) may decrease eastward. About 40 miles south of the northern White Moun- tains in the Inyo Mountains is a suite of granitic rocks in which the K,0 is somewhat higher than in com- parable rocks in the Sierra Nevada to the west (Ross, 1969, p. 34, 36). Yet both soda and lime were com- parable for the Inyo Mountains and the Sierra. Evi- dence so far collected shows that the granitic rocks of the Inyo-White Mountains are high in K,0 and that the north end of the range is, in addition, strikingly low in CaO. Ternary plots of selected oxides and normative min- erals show restricted and separate fields for each of the triangles (fig. 22). The pronounced linear trend on the Alk-F-M diagram directly reflects color index. The closest comparison that can be made between modes and norms is the ternary diagram that plots the norma- tive quartz and feldspars (quartz-orthoclase-albite plus anorthite). The northern White Mountains granitic rocks cluster closely near the border between grano- diorite and quartz monzonite (if the modal rock classi- fication is superimposed on the normative diagram) (fig. 23). The Mount Barcroft unit, as expected from modes, is lowest in normative quartz. The normative field falls over the center and average values of the modal field. The normative field of the Boundary Peak unit is only slightly displaced away from the K-feldspar corner as compared with the modal field, which prob- ably means the extra K.0O from biotite that becomes orthoclase in the norm is more than compensated for by the albite molecule in the K-feldspar that shows up as albite plus anorthite in the normative plot. As these rocks are very low in dark minerals, this distribution is expectable. The tightness of the normative field of the Pellisier Flats unit in comparison to the great spread of the modal field largely reflects sampling; the chemi- cally analyzed specimens are relatively unaltered, whereas the modal field includes a great variety of altered rocks. The trace-element contents listed in table 9 and rep- resented by the histograms of figure 24 show mainly that the granodiorite of Mount Barcroft is relatively richer in Co, Cr, Cu, Ni, Se, and V than the Boundary Peak and Pellisier Flats units, which almost certainly reflects the higher content of dark minerals in the Mount Barcroft unit, with which these trace elements are most commonly associated. Boron was below the detection limit (7 ppm) in all four samples from the Pellisier Flats unit yet ranged from 10 to 70 ppm in the Mount Barcroft unit. CHEMICAL RELATIONS 124 134 Sample 62 61 44 163 165 16 241 116 214 18 1 | | 1 | :L 17 E £ Al.O, 16 |- 15 |- 14 FeO +Fe.0,; CaO OXIDE CONTENT, IN PERCENT 56 60 64 68 72 76 SILICA CONTENT, IN PERCENT FIGURE 19.-Silica variation diagrams of granitic rocks, northern White Mountains. 21 22 OXIDE CONTENT, IN PERCENT PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA 50 55 60 65 70 75 + T g T T Southern California bar Easter Coast fill-177 a MgO Tra "f; Sigrry an $L Verse A 24 R Na.0 Western Sierra Transverse Ran [J e 4 Nevada £€°= Coast Ranges ; Eastern Sierra Nevada Southern California batholith 2 |- -I K.0 SILICA CONTENT, IN PERCENT FIGURE 20.-Silica variation diagrams comparing oxide contents of the granitic rocks of the northern White Mountains (heavy line) with other granitic suites. ANDERSON'S GRANITIZATION CONCEPT Anderson (1937, p. 1-74), from his study of the northern White Mountains, concluded that two exten- sive granitic formations, his Pellisier and Boundary Peak Granites, made up most of the granitic basement. He further concluded that the Pellisier Granite origi- nated by granitization of sediments as a result of heat, pressure, and solutions from the magma that eventually crystallized as the Boundary Peak Granite. The prin- cipal lines of evidence cited by Anderson (1937, p. 46) are gradational contacts, partially digested xenoliths, variable composition and texture of the Pellisier Granite, pseudosedimentary layering in the Pellisier Granite, and increased mafic content in the Pellisier Granite near wallrock contacts. Emerson (1966, p. 146) showed that the purported relict sedimentary bedding in the Pellisier Granite of Anderson is not related to, nor traceable into, the wall- rock. Emerson (1966, p. 146), Krauskopf (1971), and Crowder mapped intrusive contacts of Anderson's Pel- lisier Granite with its wallrocks as generally distinct and relatively sharp, although Krauskopf (1971) did note narrow zones of migmatite at some contacts. Anderson lumped other granitic masses in the Mount Barcroft quadrangle with his Pellisier Granite (Emer- son, 1966; Krauskopf, 1971), which accounts for some of the variability he attributed to this unit. Nonethe- less, the part of Anderson's Pellisier Granite now called the Pellisier Flats unit is variable; digestion of meta- volcanic wallrock material is evident in the White Mountain Peak quadrangle as well as in the migmatitic border zones in the Mount Barcroft quadrangle (Kraus- kopf, 1971). Yet the normal facies of the Pellisier Flats unit, with its small biotite clots and dull-gray color, is relatively similar over a large area. The coarse felsic facies of the Pellisier Flats unit looks like either a some- what younger core facies or a somewhat less contami- nated core facies; it is distinctive and recognizable over a large area. It seems that Anderson, in his reconnaissance study of the granitic rocks of the northern White Mountains, may have extrapolated too much from marginal con- tamination effects. And his emphasis on broad grada- tional contacts may have been based on very local observations, for there is a general pattern of relatively sharp contacts of the Pellisier Flats unit with its wall- rocks. Anderson was certainly handicapped by the lack of a good topographic base map and aerial photographs, and his study therefore must have stressed thin section petrography rather than field relations. The pitfalls he faced in trying to evaluate hand specimens and thin sections without an adequate understanding of field relations are apparent and serve as a good lesson for any petrographer. ALBITIZATION 23 | { ALKALIC ALKALI-CAlCIC CALC-ALKALIC CALCIC 10 r T 51 T. Ii 56 T I 61 J I T I I T | | § & *t § M Z L o L—I J [ea | Pu [l | z 6 —} - Ni s | f E I 4 9+} 1 8 | 3 X 0 , i a |- R 0 1 1 1 1 1 1 1 1 1 I L 1 56 60 64 r SILICA CONTENT, IN PERCENT 68 | FIGURE 21.-Peacock index of granitic rocks, northern White Mountains. ALBITIZATION Bofi granitic and metavolcanic rocks are albitized over an area of some 50 square miles. Essentially all the bedrock north of Milner Canyon (fig. 1) in the White Mountain Peak quadrangle, except for some of the metagedimentary rocks, is altered. In thin section, rocks from this area show a considerable amount of clean fresh secondary albite. Sample localities of these rocks, are shown in figure 25. Not all rocks within the area are equally albitized, but the extent of alteration in some degree is striking. The most intensely albitized rocks can be divided into three types: (1) medium- to coarse-grained "alas- kitic'' rocks composed almost entirely of fresh-looking albité and quartz, (2) similar medium- to coarse- grained rocks containing abundant K-feldspar in addi- tion to albite and quartz, and (3) rocks with well-pre- served porphyritic volcanic texture that are almost entifiply fresh-looking albite and quartz. The first two types most likely are intensely altered rocks of the Pelligier Flats unit, for transitional rocks that grade into typical rocks of the Pellisier Flats unit are present. The third type is quite obviously the result of albitiza- tion of the metavolcanic section. To confirm the anorthite content of these albitic rocks, X-ray diffraction patterns were run on three typical samples from each of the three varieties. All are more sodic than An;, and most are about An,, nearly pure albite. It has been suggested that such nearly pure albite cannot be a normal primary magmatic product (Gilluly, 1933, p. 74). The coarse-grained "alaskitic' rocks and some of the finer grained metavolcanic rocks seem at first glance to be alaskite and aplite. Closer study reveals abundant strange chessboard albite twinning and a complete absence of K-feldspar. These features, together with preserved volcanic textures in the "aplitic' rocks and gradation of the "alaskite" to rocks of the Pellisier Flats unit, leave little doubt about the parent rocks of these strange alaskites and aplites. In addition to these three types of intensely albitized rocks, the Pellisier Flats unit contains abundant evi- dence of probably related alteration in the same area. Invariably, thin sections of these rocks show intensely saussuritized plagioclase liberally sprinkled to choked with sericite, epidote, and biotite and scattered shreds and aggregates of biotite, but they do not show any amphibole. Some clean fresh albite is found, part of which has chessboard twinning (fig. 12). The pattern of present distribution suggests that all rocks of the Pellisier Flats unit south of the coarse felsic facies (fig. 9) underwent considerable alteration of original plagioclase and dark minerals Within the coarse felsic facies and in the normal gray rocks north of the coarse facies, intense albitization is not found; moreover, the gray rocks of the Pellisier Flats unit north of the coarse facies contain hornblende, which must surely have been originally present in the rocks of the Pellisier Flats unit south of the coarse facies. The most intense alteration of metavolcanic rocks generally coincides with the area of alteration of the Pellisier Flats unit. These relations suggest we are dealing with 24 PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA F=FeQ+2Fe.0, + MnO A= Al,0,-(Na.0 + K.0) Alk =K,0 +Na.0 M=Mgo C=CaO-(3P.0, + CO.) F=FeQ+MnO + MgO +2Fe.0,- TiO. Q EXPLANATION Or C armand \| $ Ab+An Or A Quartz monzonite of Boundary Peak & Granodiorite of Mount Barcroft a Quartz monzonite and granite of Pellisier Flats Ab An FIGURE 22.-Distribution of selected oxides and normative minerals, northern White Mountains. a pervasive process that affected a volcanic and granitic terrane of some 50 square miles. Anderson (1937, p. 50, 72) was the first to recognize the albitization in the White Mountains, but he appar- ently concentrated his attention on the granitic rocks, because he did not mention the similar intense albitiza- tion of associated metavolcanic rocks. He did note that metasediments in contact with what he regarded as Pellisier Granite are similarly albitized (p. 52), prob- ably referring to what are now known to be metavol- canic rocks, but there is little further mention of albitization in the wallrocks. Anderson suggested that the Pellisier Granite formed by replacement; he postu- lated that the Boundary Peak Granite furnished active granitizing and albitizing solutions that converted sedi- ments into Pellisier Granite by metasomatism. The distribution of the most intensely albitized rocks clearly argues against this thesis. The rocks of the Pellisier Flats unit nearest the quartz monzonite of Boundary Peak are much less albitized and otherwise altered than « ALBITIZATION 26 EXPLANATION Modal field § Quartz monzonite of Boundary Peak Normative field vei (BP/ (Q) ngrtz (Coarse felsic facies} ;p \ \Normal gray i019 Ney Quartz monzonite and granite of Pellisier Flats (iB O \\]§/‘ Granodiorite of Mount Barcroft (Ab+ An) (Or) Plagioclase K-feldspar FicurE 23.-Modal and normative fields for granitic rocks of the northern White Mountains. the rocks of the Pellisier Flats unit and associated volcanic rocks some distance to the south. It appears that the Boundary Peak unit was not the source of albitizing solutions. Anderson (1937, p. 15, 41, 67, 70) listed chemical analyses for four samples of Pellisier Granite described as albitized. These rocks contain from 2.7 to 4.6 percent Na,0, 2.5 to 4.8 percent K,0, and 1.1 to 3.8 percent CaO. It is frustrating that there are no modal data for these specimens, but the general chemical character of the rocks is closer to that of the strongly saussuritized rocks that retain their original granitic character than to the intensely albitized rocks with clean secondary albite. Anderson (1937, p. 45) listed chemical analyses for two samples from albite-rich bodies that he believed to be replacement bodies in the "metasediments" near the main batholith. These rocks contain about 6 per- cent Na,0 and about 1 percent each K,0 and CaO. Anderson described them as being composed almost entirely of chessboard albite and quartz, with minor amounts of biotite, sphene, and magnetite. These rocks probably are part of the intensely albitized terrane. Although no textures are mentioned, they would seem from the setting described to be albitized metavolcanic rock, but they could be albitized rocks of the Pellisier Flats unit that became mobilized and were squirted into the adjacent wallrocks. Anderson (1934) described and illustrated a texture in these albitized rocks that he called "pseudo-cata- clastic." It looks cataclastic, but because the rock con- tains abundant fresh secondary material, Anderson believed it was a replacement texture. Gilluly (1933) noted that cataclastic rocks were easier prey for replacement solutions in a vast albitized terrane in Oregon. He further noted that in other areas albitiza- tion was more common in rocks that had been crushed. Crowder, in his field notes on the White Mountains rocks, was torn between calling these rocks hornfelsed or cataclastically deformed. Nevertheless, many of these intensely albitized rocks show remarkably well pre- served original granitic or volcanic textures; therefore, pervasive shearing was not necessary for the albitiza- tion. But there is abundant evidence of shearing in this terrane, and it seems likely that numerous channelways were available to albitizing solutions. How or why the area of most intense albitization was localized is not clear. It is tempting to speculate that there is some connection with the White Mountain fault zone (fig. 1). In summary, the Pellisier Flats unit, with highly altered plagioclase, shredded aggregates of biotite, and loss of hornblende throughout the southern part of the body, probably underwent considerable change since its intrusion. The anomalous abundance of K-feldspar also attests to an unusual, and probably not original, composition. It is perhaps significant that within the area where intense albitization produced rocks from which all the K-feldspar was driven, the granitic rocks of the Pellisier Flats unit are extremely rich in K-feld- spar. Possibly the K-feldspar was redistributed in the alteration process, for it seems unlikely that the origi- nal magma that produced the Pellisier Flats unit was as rich in potassium as present modes suggest. It also seems evident that the nearby metavolcanic rocks underwent the same kind of alteration as the Pellisier Flats unit. The metavolcanic rocks were intensely albitized, they lost their original pyroxene and amphibole, and they now contain scattered shreds and aggregates of biotite, in part in the altered plagio- clase, much like the Pellisier Flats unit. It is not likely that the Pellisier Flats unit was the "altering agent"; rather, some younger unit probably provided solutions that transformed both the Pellisier Flats intrusive and its metavolcanic wallrocks. Also, the distribution of altered rocks suggests the presently exposed Boundary Peak rocks were not the source of the altering solution. It may be worth noting that the most intense albitiza- tion seems to be associated with the area of the mixed Pellisier Flats unit and metavolcanic rocks and that the granitic rocks are most altered where the elongate prong of the Pellisier Flats unit protrudes into the metavolcanic wallrocks. PETROGRAPHY OF SOME GRANITIC BODIES, NORTHERN WHITE MOUNTAINS, CALIFORNIA - NEVADA 26° *(§961) 10f4e1, wou; ore (13) opueis pue (pis) oquorpoue18 10; sofeioay 'SyJ0I OT}TUEIS Jo jUuojJU0) MHODLA S12] 4oist[[ed 30 xeoq Arepunog ;o yo aquorpoutat) aq1ue43 pus aqtuozuouw z1.en() »qruozuouw z7rent) NOITIIW ¥3d4 SIMVI NI I - mmmmwmmmsngsall va NOILYNYVTA4X3 6 o 6 6 0 hs ; ; p -r-- -se ar- 1 o #34 SLHYd NI 'NOILVHLNJONOD NOIIIW #34 NI 'NOILVHLN3JDNOD t 18 8 Sa 5 v a w n -+- sl 2 C5 2 s in w o sion - j: § §§ 5s 88 ae t - ¢ rt I t o first Tn -f TE F E 1.21 _I. (2 ae it é C -/+ F - s : 15 F a - -g I7 1M - - £ 12 48 f f pis 9d aB t 1 pas ap pas + a8 t o 0 , f a it | ate - $ - az £ # - € 7 - t IN pas * a8 + 0 ° pas t a8 t C <1 a8 A | 3x: R Lo % s a { |- u . - a Q Ind - {- -|z [ s & > [¢ < a s C sx CJ s -g IN pag-48 + 18 + 0 |- T _ A 11> C 3 0 [ gj4 IF 3 - 14 -L - ie: - - > yi e "A a8 a - + um °8 a8t _ tps E h- < £ 3 - |- - € Y o. 3, SS 3 +. s Im ST - - 4 s R & -z |- | - 9 - 1g |-- 3 - L (- -/+ 2D pag-18 A °C _ as 11 pas 0 nx 0 C 31. .E m1] S s j? C © { L: 42 ~ no __. L_! =| & |- g U ast _ as f pia (+3 (et g tsh ae ar at nic tet ane tel et o le p rer ere at aet use ey - 0 P w < m a_-A 0 S3IIWVS 10 H38WNN m ~ A 0 # m a - o m a_ _- 0 ALBITIZATION 118°30' 118"15 37°45 BENTON QUADRANGLE I 4" \ m¥ IN y {~ pate ,< Pies 3T A~/\z / / ~ Z T5 \l (227 b BAY ABI ~ Mas= 4 N ai ce d Parkman $— i( \_ @Sheridan X x loch -=L f ._. -~ deem. _ a *» As 06>» a 7&9 LJ ~Elgin Creek Cottonwood Creek B a, X \ het \\ I Cess --:. bNorth Fork .\\ xe Sal ¢ X® X L104, ‘(Zj‘eE-zkfl d 6 & x Ju v o / En 4 e__ x Ag, X 4 * co o * ""o % o / n x x / - Casper YC O M I a x | o | xX ;I Seminoe x 0. Reservoir ® o 4, co +,, th o fishes ® x wlins g o yx* 8/4, ( 300k Springs % XX“ * 3 & ® .. x 9 xX $ H A mre +n moni ale neer onan ame tally | a 108° 106° | C :O "IL 0 FIGURE 8.-Location of cross sections and principalscontrol points used in ROCKS EQUIVALENT TO THE MONTANA GROUP, WYOMING 15 3 98° 19° w ~, F 100° ae uaa c" ’-" \ 504° 18: _ ._ __r__1————" a Awaihalla | wm wan cme meme mage mam m m *~ & ' | [ 7% \ I I $ \ 2 ® | & i x x I \ t yo I A ; | .x o &i t 8 ye A \ f A f A7 f I A -G1endive l 6 .-Va“ey City 1 & i BISMARCK >.<. \ X | 6 \\\ 1 , i aie, l__-—————r———-—§—’_—__ e _- > t 6 \ ® § , Mobridge 'm. X sx x ® \ ye. :I eX o I # "+s _4\45 o l yx A A 1 ( ~~. t-" 3x - >*s"*, L K o: I 1 Se sy I € x S O U. C H D \ <«70 I X x X ® ® + I X 5 X 1 X bre x xX \ $ |,$, *e X >2(Q. Pierre % /<< e % x a \ & §. ® x e xX I @Rapid City @» x 6 1 Q/b ® be ‘ o X | C x % o A h Newcastle ® 1 C X o o o * x in > "$ xl C 4 //l/ B; Q“ Ap I R o sys- 1, g o ial 7 | P T2 Lts. _o Ll prema ft ono Wil med l _ £ (] = 98 \’~\) @ ¥: c | xE B Ra s Ko A I I « ¢ ‘ EXPLANATION | A e (x + ‘ Measured section with ammonite control I Supplemental ammonite collections X I Cheyenne l Subsurface control point a hes £ 50 o 50 100 MILES __.__._————-1-61£-—'_—‘_— 141 L LSA AL _4 | 1 R A. 1)" O I 50 o 50 100KILOMETERS constructing strandline maps, Wyoming, Montana, afid North and South Dakota. 16 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA A Dearborn River St. Mary River Formation (part) & =r ND 178 \ s l/s \/)< a> mA XTX \/ Bruno siding Hell Creek Formation (part) 50 MILES Ai ~ 1 {\~/l/\ 71 \/\'/ &1"% ~ ANy s ya {147 i< a peX 4D gn Riazi! 74 ~ /\:i:l’\’/\‘ 1/81 weal vI Wears 5 < y > I ~ /% mz I~\ / ~ \ Cois 1 are \//i/ M4 X! A Eadie a\ _\/\/ \ ~ / -I \ mal- oct » (s Aman {=/ l\l\/‘\//\~/T ariel fl I2! 7) a (/ 1% PMA) aL /~ fad) Naf I \l X2 A rM / ct 7 \ ~- /\ /\7| V ~ -R U ZN C> <7, «NZ ajM> b: 7~',\/,\‘-,\,\’| \- < A187, " /\/\|:/\\:I/_\t\/\_,:l /\' / N s (a 7 AL 1 ~ 2 NSD LN 2 s Lys MeL iF At ,/,I\ NOTE VARELA No ~ § Two Medicine { o Formation M & \ 5 g & B & El A Aas Lz r" <7 Virgelle Sandstone Telegraph Creek Formation Colorado Shale (part) Voleanic-rich rocks Cody Shale (part) E X P LA NA TIO N ash, or bentonite Colorado Shale (part) Other nonmarine rocks FIGURE 9.-Stratigraphic diagram A-A' of rocks of the Montana Group between the Dearborn River and Pocupine dome, Line of section 40 MILES Lavina Mosby 75 MILES 40 MILES tatt To- arm , too 3 l M O A K A \ A Dearborn ‘I \‘\ River 4 \ po Nl } A' m | kw a} ROCKS EQUIVALENT TO THE MONTANA GROUP, WYOMING A Porcupine Baculites grandis Baculites eliasi =-- --- - B. compressus-cuneatus- -- ___ 5s \ \ - 7 LID 4 Dw‘J Secs nw anl l mee Ardmore Bentonite Bed s-} o eral, + ment mame ean renee Parkman Sandstone Claggett Shale Gammon Shale Montana Group ls _L _L Niobrara Formation Formational contact Marine sandstone Montana. Approximate midpoint of selected ammonite zones shown by dashed lines. Vertical exaggeration x 210. Marine shale shown in figure 8. Calcareous rocks Intraformational contact 17 18 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA B Cottonwood Ronceco Zimmerman Nowater Creek mine Butte Creek North Fork 10 MILES |8 MILESSMILES 17 MILES 48 MILES 40 MILES 14 zones 12 zones T zones missing missing missing nl Lance Formation (part) Meeteetse Formation Mesaverde Formation Cody Shale (part) aG E X PLA NA TIO N thsi 2. Ts. 100 s r sL // Formational contact R s 0 1 . % Nonmarine rocks Marine shale I ~ Intraformational contact _C o sube : Marine sandstone Calcareous rocks Unconformity FIGURE 10.-Stratigraphic diagram B-B' of Cretaceous rocks of southwestern Bighorn Basin to southern Black Hills, Wyoming, selected ammonite zones shown by dashed lines. Vertical exaggeration approximately ROCKS EQUIVALENT TO THE MONTANA GROUP, WYOMING El Paso B Salt Creek Repa far tine Red Bird A | 5 zones 50 MILES 40 MILES 3 zones missing missing N F X \ Lance Formation p \\\\\\\\\ \\\ \ e mms meses s \ § -- 7 a Pam Tr ® " *. Fox Hills Sandstone // rm AOA. trm mem too- meine tun- bcs tome (ice: cos Shone | crazed " & t- --- Baculites grandis -- -- -- > Lewis Shale r f --- --- Baculites reesidet - -- -- -- __ L- - Bacubt §: : =e meio = tril > Mesaverde Formation-- -- ~- ~- ~~~ Ates SCE LA Pierre Shale f ne- tg o[ ._ o Ss f ~ ~- -- {-- -- Baculites perplecus - -- -- -- p .............. /Stray sandstone ip 1 .n t r ir Ais io Pe vene s ta Pha i -r cale . C “(fl '—<4 Ti m. =( ra --- Baculites obtusus -- 4 \s XAmflflfl—(—<flflfiflfl__—— Ps x ussex Sandstone Member more Bentonite Bed RFL x MEE ILL nila EZ | mades! ees ; muse oe apeiites Sp: femoOLh) =---A=-- -o- .no, m Niobrara MC Formation £ -s (part) A a me l. P slug . .ll no' ees 44 P E uur! "'--...to°tlz safidsm‘? ......... EL sees P al RL est sect Nitra t. "1, yes" arg | ghat showing the unconformity at base of the Teapot Sandstone Member of the Mesaverde Formation. Approximate midpoint of x 40. From Gill and Cobban (1966a, p. B22-B23). Line of section shown in figure 8. 20 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA southern Wyoming depositing the upper part of the Lewis Shale (late in zone of Baculites grandis and B. clinolobatus). The final withdrawal of marine waters from Wyoming is marked by the deposition of the Fox Hills Sandstone. CORRELATION OF ROCKS OF THE MONTANA GROUP Section C-C" (fig. 11) extends from the mouth of the Judith River in central Montana south to Seminoe Reservoir in the Hanna Basin, south-central Wyoming. It documents the complex facies changes and different nomenclature usage. This line of section presents a view that is largely parallel to depositional strike and one that passes from an area of slow and uniform deposi- tion (3,000 ft) into an area of rapid and erratic deposi- tion (at least 9,000 ft for the same time interval). East-west sections A-A' (fig. 9) and B-B' (fig. 10) rep- resent transects that are generally perpendicular to depositional strike and thus more clearly illustrate the intertonguing of transgressive and regressive deposits. Correlation of rocks of the type Montana Group exposed along the Missouri River in Montana with correlative rocks exposed in the Powder River, Bighorn, and Hanna Basins of Wyoming is based on surface sections, ammonite collections, and subsurface studies. Ammonite zones and potassium-argon and estimated dates are shown on the right side of figure 12. The type Telegraph Creek Formation and Eagle Sandstone are equivalent to the Fishtooth sandstone and the Shannon and Sussex Sandstone Members in the lower part of the Cody at some localities and to Steele Shale at other localities in the western Powder River Basin; they are equivalent to the upper part of the Niobrara Formation in the eastern part of the basin. The Claggett Shale, with its distinctive bentonite beds, one of which is the Ardmore, is equivalent to the Ardmore Bentonite Bed and to the overlying part of Sharon Springs Member of the Pierre Shale in the southern Black Hills and to the thick bentonite and shale sequence that overlies the Sussex Sandstone Member of the Cody in the Salt Creek area. A potas- sium-argon date from this level in the Claggett Shale at the mouth of the Judith River in Montana gave an age of 79.5 m.y. The Parkman Sandstone (zone of Baculites asperi- formis), as now recognized in central Montana, is older than the type Parkman (zone of Baculites perplexus) and is equivalent to the upper part of the Cody Shale in the Salt Creek oil field. The type Judith River For- mation is equivalent to the Parkman Sandstone Mem- ber and the unnamed marine shale member of the Mesaverde Formation in the western Powder River Basin and to the Allen Ridge Formation farther south. The Bearpaw Shale is equivalent to an unknown amount of strata eroded from beneath the Teapot unconformity, to the Teapot Sandstone Member, and to the lower part of the Lewis Shale. The Fox Hills Sandstone of Montana is roughly equivalent to the mid-Lewis regressive sandstone at Salt Creek and to the Dad Sandstone Member of the Lewis in the Hanna Basin. The upper part of the Lewis Shale and the Fox Hills Sandstone in the Powder River Basin are repre- sented by nonmarine strata of the Hell Creek Forma- tion in Montana. GEOLOGIC HISTORY OF THE MONTANA GROUP The geologic history of the Late Cretaceous of the northern interior is recorded in the transgressive and regressive deposits of the Montana Group and equiva- lent rocks. About 150 stratigraphic sections and several hundred fossil collections (fig. 8) afford the basis for the construction of strandline maps (figs. 13-19). These maps are highly generalized in order to show our interpretation of the position of the strand for 24 selected ammonite zones. TELEGRAPH CREEK-EAGLE REGRESSION The Telegraph Creek-Eagle regression in Montana began during the range span of Scaphites depressus, about 85 m.y. (not shown). The Telegraph Creek For- mation rises stratigraphically and transgresses time rapidly toward the east as shown in figure 13 by the strandlines of Desmoscaphites erdmanni (1), D. bass- leri (2), Scaphites hippocrepis (3, 4), and an unde- scribed smooth species of Baculites (5). This overall regression was interrupted in late Eagle time by a sharp transgression accompanied by explosive volcanism dur- ing the range span of an undescribed baculite that has weak flank ribs (6). At that time the sea expanded westward for a short period and then retreated east- ward. A pavement of black chert pebbles and granules marks this level throughout much of Montana and southern Canada. The Telegraph Creek-Eagle regres- sion was caused by tectonism and volcanism in western Montana, which lasted about 5.5 m.y., while at least 3,000 feet of volcanic rocks constituting the lower part of the Elkhorn Mountains Volcanics was being deposited. CLAGGETT TRANSGRESSION The Telegraph Creek-Eagle regression in Montana ended about 79 m.y. ago at about the beginning of the zone of Baculites obtusus (7) (fig. 14). The Claggett transgression began with explosive volcanism and sub- sidence in coastal and near-coastal areas in western Montana. In a short time the sea expanded westward in western Montana, while in southern Montana and GEOLOGIC HISTORY OF THE MONTANA GROUP 21 Wyoming it retreated. The Claggett transgression cul- minated during the zone of Baculites melearni (8); by late Claggett time (zone of B. asperiformis, 9) sedi- mentation outran subsidence, and the strand once again moved seaward, beginning the Judith River regression. The Claggett transgression lasted about 1.5 m.y., during which the strand moved westward as much as 140 miles-about 500 feet per thousand years. Many thick and persistent bentonite beds occur in the lower part of the Claggett Shale (zone of Baculites obtusus and the lower part of B. melearni). These beds appear to correlate with the middle unit of the Elkhorn Mountains Volcanics, which consists of 2,500 feet of welded tuff and ash-fall crystal tuff. About 500 cubic miles of bentonite is preserved in the Claggett Shale and its equivalents in Montana, Wyoming, and North and South Dakota (fig. 15). If the thickness of the deposits in Colorado, Nebraska, and southern Canada were known, more than twice that volume of bentonite probably would be indicated. We postulate that the Claggett transgression began with explosive volcanism and subsidence in western Montana. This was followed by uplift near coastal areas and increased sediment delivery to the sea, which halted the advancing strand and finally brought about another regression. JUDITH RIVER REGRESSION The Judith River regression took place during the span of six ammonite zones as shown in figure 16-- Baculites perplexus (10), used in a broad sense here and representing four zones, B. gregoryensis (11), and B. scotti (12)-and lasted about 3 m.y. During this time, the strand retreated eastward about 190 miles from its previous stand in central Montana during Claggett time at about 300 feet per thousand years. A similar movement seems to have taken place through- out much of Wyoming. Much coarse volcanic detritus appears in the Judith River Formation in central Montana. Very little ash is apparent in the Judith River or in its fine-grained marine equivalents to the east. It seems that this was a period of uplift and volcanism in western Montana and of uplift and increased sediment delivery in other areas in the western cordillera. BEARPAW REGRESSION The Judith River regression was followed by another episode of explosive volcanism renewed sporadically through the range span of about six ammonite zones as shown in figure 17 (Didymoceras nebrascense-Bacu- lites cuneatus, 13-18), or about 3 m.y. Thickness and distribution of bentonite beds in the Bearpaw Shale and equivalent rocks are not accurately known, but the volume is probably very much greater than that of the Claggett Shale. Continental ash beds and welded tuffs of this age are unknown at present in the western cor- dillera, but the probable source of the bentonite was the Elkhorn Mountains volcanic area. The Bearpaw transgression was not as abrupt as the Claggett transgression, although the Bearpaw strand- line moved farther west in Montana, 200 miles as com- pared with 140 for the Claggett. It seems that subsi- dence and explosive volcanism were episodic for a long time during which volcanic detritus continued to be delivered to the sea in considerable volume. Subsidence was greater than sediment accumulation, allowing marine waters to inundate the former coastal plain. While the sea advanced into western Montana, it retreated across eastern Wyoming, clearly showing the importance of local crustal instability in effecting trans- gression or regression. Stratigraphic data show that while Montana was subsiding, central Wyoming was being uplifted and eroded (Gill and Cobban, 1966a; Reynolds, 1966; Zapp and Cobban, 1962). FOX HILLS REGRESSION, INITIAL PHASE Marine waters finally withdrew from Montana dur- ing the Fox Hills-Lennep regression (fig. 18). For clarity, this event is shown in figures 18 and 19. The retreat began during the zones of Baculites cuneatus and B. compressus (17-18). The close and parallel spacing of strandlines for B. reesidei (19), B. jenseni and B. elias (20-21), and B. baculus (22) indicates relatively slow and uniform withdrawal. In Wyoming, however, the sea, after a regression during B. cuneatus and B. compressus time, expanded rapidly until the time of B. baculus. The Deer Creek volcanic area, east of Livingston, Mont., appears to have influenced the strandlines at this time. The large eastward bulge of strandlines in northern Wyoming and southern Mon- tana shows the beginning of what became an important paleogeographic feature in later Cretaceous time. FOX HILLS REGRESSION, FINAL PHASE The waning state of the Late Cretaceous sea in Mon- tana is shown in figure 19 by the strandlines of Bacu- lites grandis (23) and B. clinolobatus (24). These strandlines outline an elongate east-trending arcuate peninsularlike mass of dominantly nonmarine rocks that extends from northwestern Wyoming to eastern Montana and the western parts of North and South Dakota. This mass is interpreted as a deltaic complex, referred to here as the Sheridan delta, that separated Montana and Wyoming into distinct depositional provinces. The Sheridan delta was bounded on the north by the Mosby embayment, in which fine-grained rocks of the Bearpaw Shale accumulated, and on the 22 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA C Judith River Mosby Hardin 90 MILES 87 MILES 58 MILES ssi -> [ c A C | & l \, MONTANA t | \ < y \ yves pane A a | l \ | _ WYOMING ll I \ I the & hoc enc $ Hell Creek Formation (part) Fox Hills Ss Hell Creek Formation (part) Bearpaw Shale Judith River Formation Montana Group Parkman Sandstone Claggett Shale a11- 0 inst te icc cll ccs Buculites melearni omar .-, -t-) Eagle ‘ Sandstone Telegraph Creek | tion -__ ~ -__ Cody Shale tin (part) - | Colorado * Shale meetal (part) - ack» |-1500 | T [--- uae ward AN a. T T 0 N f |-1000 * 7 el: / Formational contact Nonmarine rocks Marine shale S Intraformational [- contact k-_0 Unconformity Marine sandstone Calcareous rocks FIGURE 11.-Stratigraphic diagram C-C' from mouth of Judith River, Montana, to Seminoe Reservoir, south-central by heavy dashed lines. Vertical exaggeration GEOLOGIC HISTORY OF THE MONTANA GROUP CI Parkman Elgin Creek North Fork Salt Creek Casper Canal Seminoe Reservoir Medicine Bow 54 MILES 38 MILES 33 MILES 51 MILES 38 MILES Formation (part) Fox Hills Sandstone Lance # <|& Formation / E & (part) _ / 6A z) 0 o|P R|E 4 Dad Sandstone | - Lewis Member Shale Almond Formation Pine Ridge Ss Lance Formation (part) / Allen Ridge Formation dor reb A e .n_-:_ --Bearpaw Shale - /rMesaverde F rx tion ............. as s ................ -ma & 0 ..... hs _ $ een eee ss Lo t dees mane rer imp ollo PLL on ARA alll a Ardmore Bentonite Bed $ y-] y- ojy- op- - ifl omote o toate mute M = : Sussex Sandstone Member Haystack ...... Mountains Formation Fak Shannon _ Sandstone _ Member - mL. : o ith ivupcst 4 y- sme tant ___. sa tited m ae LL 1s "RN. soe P =C i a Cody Shale S =-- Nioby ~ (part) ~ mee ees ara 2 k Shale ef <<= Steele Member Shale _L [7 Ik. [-- -= Niobrara -L- Formation (part) Wyoming, showing major lithologic and nomenclature change. Approximate midpoint of selected ammonite zones shown approximately x 160. Line of section shown in figure 8. 24 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA Upper Cretaceous Powder River Basin stag): and substages Judith River Hardin- Billings Parkman Salt Creek Upper Lance Hell Creek Hell Creek Formation Formation Formation Maestrichtian Lance Formation fre Pi- Lower Fox Hills Sandsto: Fox Hills Sandstone Fox Hills Sandstone Se t A q Fox Hills Sandstone Lewis B Shale (tes Bearpaw Bearpaw Shale s Teapot Ss Mbr Pe Shale g ~~~ xr x~ _- 3 S 5 E o & he: U is Shale y \\ 8 3 B E é i | 5 Marine 5 + Sepe -| 18 Judith River 3 3 Formation es E, E C Sampanish Parkman £31531; Parkman Sandstone Sandstone Parkman Member Sandstone Claggett Shale Claggett Shale Stray sandstone Shale Shale mr Roi g 6 Coniacian 0 FIGURE 12.-Correlation of the Montana Group, GEOLOGIC HISTORY OF THE MONTANA GROUP 4 R i Potassium- Estimated nglgfi: Hating Stratigr 82h“: section argon dates dates Western interior Basin Basin Red Bird and vicinity Millions of years ammonite sequence 63 63 Ferris Formation (part) 64+2 64 ? Lance 65 Formation Lance Formation 66+2 66 Medicine Bow et Formation 68 Discoscaphites nebrascensis Discoscaphites rouanensis Fox Hills Sandstone 69 Sphenodiscus (Coahuilites) Fox Hills Sandstone Baculites clinolobatus x '< Dad Ss Mbr (Liz: 33:12? 70 70 Baculites grandis E E Baculites baculus in Meetsetss a Kara m Baculites eliasi 8 a Lewis Shale Alaond Bentonitic Member Baculites jenseni prmlarion Formation : au T2 Baculites reesidet Pine Ri Sandstone --\.f:r.9!lp°t o ick Ren ys Baculites cuneatus T5 +2 T3 Baculites compressus Lower unnamed shale member Didymoceras cheyennense 74 Exiteloceras jenneyi Didymoceras stevensoni § Marine member % T5.5+2 T5 Didymoceras nebrascense » fk P- 3 g w Baculites scotti, Menuites E Fol Allen Ridge § s s é 3 Formation g Red Bird 76 Baculites gregoryensis o g s -» Silty Member Baculites perplezus (late form) & o E: g 33 TT Baculites gilberti p = | E Hatfield Pucult a : aculites perplecus (early form i J”) & Sandstone Mitten ? E Member Emaiztle T8 Baculites sp. (smooth) IE Baculites asperiformis E c Mamba o 19.5 T9 Baculites mclearni 2 O'Brien Spring | -a -4 - -6 - Cl “5; nulpnng Baculites obtusus a a 80 Baculites sp. (weak flank ribs) Tapers Ranch | ammon 4 a Tapggsfi‘nc Ferruginous Baculites sp. (smooth) Member 81+2 81 Scaphites hippocrepis (fine ribbed) III Sstfaell: [-* Scaphites hippocrepis (coarse ribbed) II 82 Scaphites hippocrepis (coarse ribbed) I H Desmoscaphites bassleri Cody 83 Desmoscaphites erdmanni Shale Niobrara Clioscaphites choteauensis (part) Formation Niobrara 84 Clioscaphites vermiformis Formation 834-3 Clioscaphites sazitonianus 85 Scaphites depressus | 87+3 Scaphites ventricosus | Frontier 86 Scaphites preventricosus Formation (part) Montana, with equivalent rocks in Wyoming. 25 26 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA 114° 112" 110° 108° 106° 104° 100° I | | y ""~ A? Cut Bank 49% Billings | | cAmNAnA& _ __ __. UNITED STATES 1 P Glendi or "~ STRANDLINES 6 Baculites sp. (weak flank ribs) 5 Baculites sp. (smooth) 4 Scaphites hippocrepis II-III 3 Scaphites hippocrepis I 6 2 Desmoscaphites bassleri 1 Desmoscaphites erdmannmi v I I NORTH DAKOTA_ ___ pm n = emmm cae on mem I MONTANA - j was am mur aam 1 A Sheridan 1 Rapid City I S8 1 f soOUTH DAKOTA _ ___ . fee, l”— ~*~ NEBRASKA I I Rawlins » I wYomINg | a winn on A *~ tos" "__COLORADO | so o 50 100 MILES 50 100 KILOMETERS FIGURE 13.-Approximate position of strandlines during the Telegraph Creek-Eagle regression in Montana and Wyoming. Barbs show direction of strandline movement. rom ir e nr ery ote mm rr n amram comme m. GEOLOGIC HISTORY OF THE MONTANA GROUP 27 114° 112? 110° 108° 106° 104° 102° 100° I I I 1 FT ~~ I i I 49° fr mnm am me = m mos I- CANADA an Chiapas us me ___J_,___——-— UNITED STATES 1 Cut Bank\ M T. = Havre 1 I m | STRANDLINES w Zr y ; ; ; N“; 9 Baculites asperiformis rmx S (¢ I 8 Baculites mclearni ' mage Q» s £1 c 1 7 Baculites obtusus | 7, Reo " _ Z ”Kw Glendive 6 Baculites sp. (weak flank ribs) 47°L- it 7% mi] /e. 3 £ | ; \;__m\ At I | l. (E} 1 . .- Pm. 3) | léé‘iiq/ NORTH DAKOTA_ ___ h P9 Hs... o --- --- *~ A # ,/Q>\ # .Blllmgs F MONTANA I ye wa on comme mm mn commmime me mn memes 1 a Sheridan l 1 Rapid City I % I | SOUTH DAKOTA u w ***. f: ~ NEBRASKA | I Rawlins 1 | WYOMING as fie Faes J "I__COLORADO | 50 100 MILES 50 0 50 100 KILOMETERS Coi T> fy _: | FIGURE 14.-Approximate position of strandlines during the Claggett transgression. Barbs show direction of strandline movement. 28 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA 49£16° oo az 114° 11s ', T—_ \ 110 108 I t g A 5 y & & Ra) 0 M %> # I ig N. * r---- --- \,_,.J.,J\' 'a I i I 43°i— wrommg \ I I $2 | C // 41°L~L_/____ af _s MONTANA 100° A ae " Lyf g J NORTH DAKOTA _\J ~sSOUTH DAKOTA ’\ I -A a _| N M accu ea n ~ ig Me- g -m f so o so 100 MILES so 0 50 100 KILOMETERS FIGURE 15.-Thickness (in feet) and distribution of bentonite beds deposited during the Claggett transgression. Zones of Baculites obtusus and B. melearni. east in the Dakotas by the open sea, in which rocks of the Pierre Shale were deposited. The Mosby embay- ment was flanked on the west and south by coastal ranges formed by the Elkhorn Mountains and Deer Creek volcanic centers. These ranges seem to have deflected sediment southward, concentrating it in the Sheridan delta. The Fox Hills regression from Montana is estimated to have lasted about 2.5 m.y. Apparently it was slow and regular at first but rapid near the end, as shown by the fact that the strand retreated more than 250 miles during the zone of Baculites grandis, about 70 m.y. ago according to potassium-argon determinations from the biotite of a bentonite. This final regression of the sea cannot now be defi- nitely related to either volcanism or tectonism. Pos- sibly it resulted from slow subsidence and subsequent filling of the Montana part of the depositional basin, though the thinness of the regressive nearshore marine sandstones seems to indicate otherwise. Thick accumu- lations of Upper Cretaceous and Tertiary continental beds indicate that the area continued to subside after the sea withdrew, but the absence of coarse clastics fails to suggest any marked uplift in the western cor- dillera. A eustatic lowering of sea level would seem a logical explanation for the withdrawal of the sea if Late Cretaceous transgressive and regressive events had been confined to the Montana part of the basin of depo- a GEOLOGIC HISTORY OF THE MONTANA GROUP 114° 110° 108° 106° 104° 29 | | | J | | 1 E emm as is manis t af Aires -—l-- A Cut Bank is CANA an ca an wegen UNITED STATES _‘ Havre® B 1 MONTANA _ j ———_1 '_—-———_— STRANDLINES 12 Baculites scotti 11 Baculites gregoryensis 10 Baculites perpletus 9 Baculites asperiformis NORTH DAKOTA_ ___ _ Rapid City soUTH DAKOTA_ ___. ~ NEBRASKA I Rawlins i f x f -I .ROCk Seite ~ I ‘f';/~ % P % Cy yl 41°. EL I & a 7° ; J ‘-—--—-J_fi_-__J__&‘LOM£‘E—- wae a 9 -A UTAH _| "[__COLORADO | 50 o 50 100 MILES 50 o 50 _ 100 KILOMETERS FIGURE 16.-Approximate position of strandlines during the Judith River regression. Barbs point in direction of strandline movement. 30 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA 114° 112° 110° 108° 106° 104° I I I 1 | x or ~~~ f 1 E 49° \{p Cut Bank Pj—n—--___ = m a 'm aa CAI-qllDA he s lus us ___J---——-- "A a 1 1 UNITED STATES 8 o -A ¥ -A 1 -a Havre - 12 STRANDLINES 18 Baculites cuneatus 17 Baculites compressus 16 Didymoceras cheyennense 15 Exiteloceras jenneyt ; 14 Didymoceras stevensoni Glendive 13 Didymoceras nebrascense - inn 12 Baculites scotti | NORTH DAKOTA_ ___ . g < a " ** Rapid City #s Rock Springs i soUTH DAKOTA_ __. l" ~*~ NEBRASKA I L 1 I in ot at cs s 2 wYOMING | mpd f P o- OLORADO 50 0 50 100 MILES Factor le d __ 122 _ 50 0 50 100 KILOMETERS melons FIGURE 17.-Approximate position of strandlines during the Bearpaw transgression. Barbs point in direction of strandline movement. GEOLOGIC HISTORY OF THE MONTANA GROUP 31 114° 112' 110° 108° 106° 104° 102° 100° | | | I I | a | t l I I RJ In ims is a uel CANADA io tage ____\,_____--- —\ UNITED STATES —‘ Ci .Cut ank I3 a H I <0 fo ‘é ‘Q avre B l STRANDLINES 22 Baculites baculus 21 Baculites eliasi I 20 Baculites jenseni c d'| 19 Baculites reesidei lita 43 18 Baculites cuneatus --I a 17 Baculites compressus Mosby 4 I A7 tie,. f i "Z oue. §. > ‘ {A 3s. Yale tte a - ot Zin. _| \ we y Billines \___:;// Rot.: m, «Livingston s f 1 "CK" age éN *""/ '7=18 as \-. __ Fauth 'f MONTANA >- 3% >: + ~ es Sheridan gy d % | y e ad f || Rapid City £ I pakora _ __. e. NEBRASKA I I 7% Raw x ~ awlins 7 Rock Springs 5V .q A : m & ¥ | J 1 f WYOMING q y -- ni ~ "_ COLORADO | 50 0 50 100 MILES 50 0 50 100 KILOMETERS cd c __| FIGURE 18.-Approximate position of strandlines during the initial phase of the Fox Hills regression. Barbs show direction of strandline movement. 32 MONTANA GROUP AND EQUIVALENT ROCKS, MONTANA, WYOMING, NORTH AND SOUTH DAKOTA 114° 112" 110° 108° 106° 104° 102° 100° I I I T l l Ff "~~ I 49°je comm on om s mm |-- CANADA 3 as 'we J-—_—-- r ~ UNITED STATE Havre STRANDLINES 24 Baculites clinolobatus 23 Baculites grandis 22 Baculites baculus Pis «l Mosby embayment a> 3 Glendive 3aa X/4/ /,/%l\ . Angston - N ~~ . \. -Z. __ Rapid City IB soUTH DAKQTA_ ___ . 1 I l”- ~*~" NEBRASKA Rawlins WYOMING -=- 50 0 50 100 MILES | | 4 af COLORADO j 50 0 50 100 KILOMETERS o_ _L. ___] FIGURE 19.-Approximate position of strandlines during the final phase of the Fox Hills regression in Montana. Barbs show direction of strandline movement. GEOLOGIC HISTORY OF THE MONTANA GROUP 33 sition, but data from other areas of the western interior show that those events were not so confined. Among possible causes for the final regression, the most attractive is a broad regional uplift in central Montana. The final stages of emplacement of the Boulder batholith in western Montana may have brought about such broad regional movements and influenced the marine withdrawal. Robinson, Klepper, and Obradovich (1968, p. 558) stated that the bulk of the Boulder batholith was emplaced in the interval of 78-72 m.y. ago. The 72-m.y. date is about the same as we estimate for the start of the Fox Hills regression. Data are not conclusive, but several recently deter- mined potassium-argon dates for the Boulder batholith and for marine Cretaceous rocks in the area suggest that the regression of the Bearpaw Sea and the deposi- tion of the Lennep, Horsethief, and Fox Hills Sand- stones coincide with late stages of batholith emplace- ment (Robinson and others, 1968, p. 574, fig. 6). Many geologists have considered eustatic rise and fall of sea level responsible for the formation and destruction of epicontinental seas. If sea level is nearly constant, local crustal instability becomes the main factor controlling the position and configuration of the basin of deposition; moreover, crustal instability, whether it affects the basin and adjacent land inde- pendently or concurrently, along with the rate of sediment supply, determines the distribution of trans- gressive and regressive deposits, and we think that was the situation here. If transgression or regression were due to eustatic or epeirogenic movements, that movement in the same sense should be basinwide. But the strandlines of the late Santonian, Campanian, and Maestrichtian Stages in a 300,000-square-mile area in Montana, Wyoming, and North and South Dakota in the western interior basin clearly record independent movements in the various parts of the basin. _ RATES OF TRANSGRESSION AND REGRESSION Ammonite zonation, mapping of strandlines, and potassium-argon dating permit paleogeographic recon- structions and determination of rates of transgression, regression, and sedimentation. Cross section A-B, in figure 20, represents a highly generalized transect across part of the Montana basin of Late Cretaceous deposition. Available data indicate that the Telegraph Creek, Eagle regression started about 85 m.y. ago and lasted about 5 m.y., during which the strand moved eastward about 240 miles. In the area of the section, the regres- sion was about 180 miles in 2.5 m.y., a rate of about 70 miles per million years. The rate for the entire Tele- graph Creek-Eagle regression was about 50 miles per million years. The Claggett transgression, accompanied by explo- sive volcanism, was rapid and short. It lasted about 1.5 m.y., and the strand moved about 95 miles per million years. The Judith River regression lasted about 3 m.y., with the strand retreating at about 60 miles per million years. "77777 70 Fox Hills Sandstone? 85 miles in Bearpaw Shale: r a 205 miles in 3.5 my. - ' 34 Depositional and faunal facies of Great Basin Silurian coral- Family Tryplasmatidae 36 bearing rocks 5 Tryplasma 36 Great Basin Silurian reference S@CUONS ----------~--~-----~---=--------- 8 SOlLATY-TU&ALC @IOUp 37 Mazourka Canyon reference section--- - 8 Fasciculate-cylindrical' group -----------------------«---- 37 Ikes Canyon reference section------------------- - 9 Rhabdocyclus a 38 Roberts Creek Mountain reference Section ----------------------- 10 Palaeocyclus 39 Coal CanyON ref@r@NCE 10 Zelophyllum --- 40 Northern Panamint Range reference section --------------- 12 Family Kodonophyllidae 40 Lone MOUntain ref@reNC@ S@CUON 12 Subfamily KOdONOPhyIliN@@ ------<--<------~------------------ 40 Rugose coral zonation of the Great Basin Silurian ----------------- 13 KOdonophyllMm, nec ence 40 _ Zone A 14 Subfamily 41 Zone B 14 Mucophyllum 41 Zone C 15 Family nemen nece enne eo-} 42 Zone D- 15 Arachnophyllum --- 42 Zone E 15 Family Lykophyllidae 43 Stratigraphy and rugose corals of the Lone Mountain and Ryderophyllum - 44 Laketown Dolomite 16 Pycnactis 45 Rugose corals and geologic correlation of Silurian rocks within Family Cystiphyllidae 45 the Great Basin 17 Microplasma 46 Zone A 20 Family Goniophyllidae 46 Zone B 20 Rhizophyllum 46 Zone C 21 Family Kyphophyllidae 46 Zone D 21 Kyphophyllum 47 Zone E 21 Petrozium 47 Great Basin Rugosa and correlation with distant Silurian rocks- _ 22 Entelophyllum 48 Zone A 22 Entelophylloides 49 Zone B 28 Subgenus Prohexagonaria, new subgenus ----------- 50 Zone C 24 Neomphyma --- -- "B Zone D 24 TONRIMGTIQ, NEOW GONUS neenee cence e> 51 Zone E 24 Family ChONOPhyIliG@@ nnn enne neenee neenee 52 Correlation of Lone Mountain and Laketown Dolomite---------- 25 Chonophyllum 52 Age conclusions based on Silurian Rugosa---------------------------- 26 Family Endophyllidae 54 Comparison of Silurian coralline rocks in the Great Basin Australophyllum 54 with those of other regions 27 Subgenus Toquimaphyllum, new subgenus -------- 54 Depositional features of Great Basin Silurian coralline rocks Family Acervulariidae 55 in relation to the r@@f scence} 28 Diplophyllum - 56 Dasycladacean algae in Great Basin Silurian coralline deposits- 29 Genera with no family deSigN@AUON-------------------------------- 56 Classification of Great Basin Silurian Rugosa ----------------------- 29 Salairophyllum 56 Systematic and descriptive PaIEONLOIOGy -<----------------------------- 30 DenayphyllUm, NEW &ENUS nene ece cee 56 Family StreDt@IASM@tGA@ nene ence eee 30 | Locality register 57 Rhegmaphyllum --- - 80 | References --- 59 Brachyelasma 31 | Index 63 III PrateE FIGURE . Index map showing principal areas of Silurian coral-bearing rocks referred to in text . Map of Great Basin showing major lithologic belts, distribution of Silurian reference sections, and coral localities ------------- . Sketch of the Mazourka Canyon reference section, northern Inyo Mountains, Calif . Correlation chart of Great Basin Silurian formations,, showing lettered coral zones . Correlation chart showing Gotland stratigraphic units and rugose corals related to Great Basin forms ------------------------------ . Diagram showing stratigraphic occurrence of characteristic Great Basin Silurian rugose COral g@N@ra-------------------------------- CONTENTS ILLUSTRATIONS [Plates follow index] Dalmanophyllum, Brachyelasma, Rhegmaphyllum, Palaeocyclus, Rhabdocyclus, and Tryplasma. . Tryplasma, Palaeophyllum?, Stylopleura, and Maikottia. . Stylopleura and Palaeophyllum. . Kodonophyllum, Diplophyllum?, and Crassilasma?. . Mucophyllum, Arachnophyllum, and Cyathophylloides. . Ryderophyllum, Crassilasma?, and Pycnactis. . Tonkinaria, Microplasma?, Rhizophyllum, and Denayphyllum. . Chonophyllum and Cyathactis?. . Entelophylloides (Prohexagonaria) and Petrozium. . Entelophyllum and Tryplasma. . Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. . Australophyllum (Toquimaphyllum), Australophyllum, and Salairophyllum?. . Kyphophyllum nevadensis, n. sp., and Neomphyma crawfordi, n. sp. . Kyphophyllum and Australophyllum. . Stylopleura, Rhabdocyclus, Palaeocyclus, Pycnostylus, Entelophyllum, and Australophyllum (Toquimaphyllum). . Brachyelasma, Stylopleura?, and Verticillopora. Sketch of the Roberts Creek Mountain reference section, Roberts Mountains, Nev - Comparative diagram illustrating present usage of the stratigraphic name Lone Mountain Dolomite ---------------------------.---- . Correlation chart showing Great Basin Silurian coral zones and common rugose coral genera -------------------------- Page 11 13 18 23 SILURIAN RUGOSE CORALS OF THE CENTRAL AND soOUTHWEST GREAT BASIN By CHARLES W. MERRIAM ABSTRACT Corals representing 13 families of Silurian Rugosa from limestones and dolomites of the central and southwest Great Basin are described, classified, and figured. Coral-bearing Silurian beds of this province occur in two contrasting carbonate rock facies: the eastern dolomite belt and the intermediate limestone belt. A third major Silurian rock suite characterizes the western, or Pacific Border, belt, which extends from the western Great Basin to northern California and southeastern Alaska. On the basis of rugose corals and associated fossils, the Great Basin Silurian is subdivided as five coral zones, lettered A through E in ascending order. These provisional zones are a result of detailed strati- graphic studies and geologic mapping of reference sections in areas extending from the Inyo Mountains northeastward to the Roberts Mountains and northern Simpson Park Mountains. Of importance environmentally, as well as with the identification and correlation of Great Basin Silurian, are the large dasycladacean algae associated with Rugosa. As the genus Verticillopora, these algae appear to have peaked in coral zone D. Rugose corals of special importance in correlation with distant Silurian rocks are Palaeocyclus, Dalmanophyllum, Kodonophyllum, Mucophyllum, __ Arachnophyllum, - Toquimaphyllum, - and the lykophyllids. The closest foreign correlations are with the Gotland section, a Silurian carbonate standard for western Europe. Fairly close similarities are recognized with Silurian of Czechoslovakia and Eastern Australia. INTRODUCTION Monographic treatment of Silurian Rugosa emerges as a late byproduct of Great Basin Silurian and Devonian stratigraphy. Beginning in 1933, geologic mapping of middle Paleozoic exposures in the central and southwest Great Basin stimulated search for dependable means of identifying and subdividing monotonous - Silurian carbonate rocks. Above all, there existed need for defini- tive criteria whereby Ordovician and Devonian dolomites might be separated from seemingly identical carbonate strata of the Silurian in areas of complex geologic structure. Rugose corals seemingly filled this need. Progress was slow during initial stages of the investigation because of discouraging internal preserva- tion of silicified coral material from dolomite. Later discoveries of limestone faunas better suited to thin section study have largely removed these obstacles. Mapping in recent years over large areas of the Great Basin by several U.S. Geological Survey field parties has brought to light numerous coral-bearing Silurian exposures. Resultant correlation and integration of data from the many isolated occurrences has made possible a composite Silurian sequence based largely on coral faunas. This succession parallels, in some respects, that of the western European Gotland standard. Partly empirical, partly inferential, and assuredly provisional, the proposed Great Basin coral succession requires the field and laboratory testing which will follow in the course of continued mapping and stratigraphic study of these yet little known rocks. In its present state the composite scheme is nonetheless a workable, albeit loose- knit, framework for evolutionary and taxonomic research upon Cordilleran Silurian Rugosa, the primary objects of this study. Research upon Great Basin Silurian Rugosa has proceeded concurrently with investigation of Pacific Border province Silurian corals of the Klamath Mountains and Alaska, and with monographic study of the Early and early Middle Devonian Rugosa of the central Great Basin. Collectively, these studies provide opportunity for comparison of coral biotas of different facies and a means of evaluating expected paleontologic changes near the Silurian-Devonian boundary. PURPOSE AND SCOPE OF INVESTIGATION This report describes and illustrates representative Silurian Rugosa and discusses their application to strati- graphic zoning and correlation of Great Basin Silurian rocks. Among ancillary objectives are classification of Silurian - regose corals, determination - of their environmental significance in connection with deposi- tional facies, and application of coralline biofacies data to problems of geologic correlation. Finally, the Rugosa are considered in the light of their value to interpretation of Silurian historical geology in the Great Basin province and the Cordilleran belt generally. HISTORY OF INVESTIGATION Presence of halysitid chain corals was ample justifi- cation for Silurian age assignment by pioneer geologists attached to early Great Basin surveys, up to and including the Eureka district work by Hague and Walcott (Hague, 1892; Walcott, 1884). Some halysitid-bearing rocks initially called Silurian are doubtless Late Ordovician 1 P/ SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN (Richmondian) of today; the Silurian System was more inclusive prior to adoption of the Ordovician as an inde- pendent system by the U.S. Geological Survey. So far as known, the Rugosa did not figure in determining the Silurian age of the Lone Mountain Dolomite (restricted) until current studies. Coral faunas of the Laketown Dolomite at Gold Hill, Utah, were known to include Rugosa when reported upon by Kirk (in Nolan, 1935, p. 18). With the examination of Silurian limestones in the Roberts Mountains, Nev. (fig. 1), during the 1930's (Merriam, 1940, p. 12), rugose corals of these somewhat more hospitable facies became available for study. Duncan (1956) documented all known occurrences of Great Basin Silurian Rugosa up to the 1950's. Geologic mapping of the Cerro Gordo mining district beginning in 1946 (Merriam, 1963a) provided opportunity for stratigraphic and paleontologic study of coral-bearing Silurian rocks of the Inyo Mountains and the adjacent Panamint Range (fig. 1). At that time the Mazourka Canyon reference section was measured, and rugose coral collections from the Vaughn Gulch Limestone were made. Geologic mapping and stratigraphic investigation of Paleozoic strata in the northern Panamint Range by J. F. McAllister beginning in 1987 (McAllister, 1952) provided much of the best Silurian rugose coral material from the Hidden Valley Dolomite. Current mapping in the Funeral Mountains by McAllister for the U.S. Geological Survey has resulted in additional collecting of coral material from these rocks. Renewal of geologic mapping in Paleozoic rocks of central Nevada came with initiation of the Kobeh Valley study by T. B. Nolan and Merriam in 1958, giving opportunity for stratigraphic work and fossil collecting in the Lone Mountain Dolomite of areas within and adjacent to the Eureka mining district (Merriam, 1963b). During this period, comparative studies dealt also with Silurian coral-rich limestone facies of the Roberts Mountains, the Toquima Range, and the Simpson Park Mountains. In 1968 the U.S. Geological Survey initiated a strati- graphic study by T. E. Mullens of the Roberts Mountains Formation in - north-central - Nevada. Under a comprehensive program bearing upon problems of ore occurrence and genesis, this investigation was under- taken to support detailed geologic mapping of the structurally complex terrane encompassing the Cortez and Carlin gold mines. Participation by Merriam has entailed identification of rugose corals and other fossils in Silurian and Early Devonian strata. In these economically im- portant areas, the Late Silurian faunas of coral zone E are represented and the overlying Helderbergian (Early Devonian) Rabbit Hill Limestone has been recognized. Research upon Silurian Rugosa of the Klamath Moun- tains, northern California, and of the islands of south- eastern Alaska was in progress during this investigation. Comparison with these Pacific Border Silurian rugose corals has had an important bearing upon the coral taxonomy and upon correlation and facies analysis of the Great Basin Silurian rocks. Silurian Rugosa in dolomite facies of the Sandpile Group of northwest Canada have been investigated by Norford (1962), providing for the first time a basis for comparison of Great Basin Silurian with Silurian of the northern Cordilleran region. Oliver's (1964) contribution on the slipper coral Rhizophyllum brings together what is known of this diag- nostic rugose coral genus in the central Great Basin, the Inyo Mountains, the Klamath Mountains, and Alaska. METHODS OF STUDY Stratigraphic investigation conducted jointly with geologic mapping is the background of these Silurian coral studies. The framework of vertical succession and coral evolution is of necessity theoretical, but detailed mapping procedures help minimize the amount of inference which attends stacking of composite sections in a region of complex geologic structure and rapid facies change. Section measuring and fossil collecting without mapping control are far less dependable; experience demonstrates that the better and more complete sections for measurement are likely to be disclosed during later phases of a mapping program. Reference stratigraphic sections employed in zoning the Great Basin Silurian corals are in geologically mapped areas or in areas where mapping is in progress. Some of the fossil collections were made close to Brunton compass and tape traverses within mapped areas. Other collections are weathered surface material from outcrop bands 200 or more feet wide and may include float from a greater interval. Attempts were made to find the same species in situ. Stratigraphic and taxonomic studies of Silurian Rugosa depend upon comparison with species from classic European sections, among which are those of Gotland, Sweden, and of Czechoslovakia. The Gotland section (fig. 8) is a world Silurian yardstick for the coral-bearing carbonate facies. Since Wedekind's 1927 treatise on Rugosa of northern Gotland there have been no comprehensive paleontologic studies of entire Gotland rugose coral faunas in relation to field stratigraphy. Most Gotland Rugosa still require photographic illustration of thin sections, and much additional detail is needed on field occurrence, stratigraphic ranges of species, and faunal - association.. The same applies to the Czechoslovakian Rugosa, known mainly from exterior figures (Poéta, 1902) and requiring thin-section study and establishment of species ranges. Study of fine structure of the Rugosa depends on preser- vation of material, which ranges from retention of minute INTRODUCTION 124° 1227 120 118° 116° 114° 112° T T T T T f W 44° |- D\/"\ Challis Eugene Bend 4 OREGON coa" pProcatello 0 42° |- J > »Kiamath Falls Crescent -- -~ U City so ce jus: one ous Wis bout Paas soils se _—-G-= Logan-16 17 Ogden Fa ® It LakeCity 8 a_ 40° |- | ad § x , u'> "js ? S & Pt I £1 ~ [ om UTAH G NEVADA A a | 38° |- : m' San Franciscop pTonopah Pioch I 1 I 1 - |- \D1=eatty O ~ 18 C33 gCerro Gordé) 36° |- y 19 "Z. Las VegasD ~ \\ ARIZONA \\ Bakersfield Kingman Flagstaffo 1 1 1 1 L 1 0 50 100 150 MILES [PLLA _ __1 EXPLANATION 1. Kobeh Valley at Lone Mountain 12. San Francisco district 2. Roberts Creek Mountain in the 13. Thomas Range Roberts Mountains 14. Deep Creek Range at Gold Hill 3. Simpson Park Mountains, 15. East Tintic Mountains north end at Coal Canyon 16. Logan area 4. Fish Creek Range, south end 17. Randolph area 5. Antelope Valley 18. Bare Mountain area 6. Toquima Range at Ikes Canyon 19. Funeral Mountains 7. Carlin gold mine area 20. Panamint Range, northern part 8. Ruby Mountains, southern part 21. Inyo Mountains at Cerro Gordo mine 9. Antelope Peak, Elko County 22. Inyo Mountains at Mazourka Canyon 10. Ely Springs Range 23. Taylorsville area 11. Confusion Range 24. Northeast Klamath Mts; Gazelle area FIGURE 1.-Index map showing principal areas of Silurian. coral-bearing rocks referred to in text. 4 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN thin-section detail of wall features in unsilicified lime- stone material to complete loss of fine structure in silicified corals from dolomite. Many of the dolomite corals were obtained by block etching; these specimens usually make poor thin sections. Sections of unetched dolomite corals may reveal patches of fine structure where silica replacement is incomplete. To avoid loss of detail in the silicified corals, thicker slices are usually more satis- factory. Silicified material well enough preserved for study of the internal characters is uncommon; therefore, character- ization is based to a considerable extent on gross external features, and quantitative morphologic studies must await more extensive collecting. Description and classification of Silurian rugose corals here dealt with are based on gross features of exterior and interior. In some families, such as the Tryplasmatidae and Kodonophyllidae, fine structure of wall and septa will eventually be useful taxonomically (Wang, 1950; Kato, 1963). With regard to photographic illustration, enlarge- ment of critical details to X 8 or greater is of value for identification and future taxonomic investigation. ACKNOWLEDGMENTS Acknowledgment is made to those U.S. Geological Survey field geologists engaged in mapping of Great Basin Silurian rocks whose fossil collections added materially to this report. Among these contributors and the areas of their mapping efforts are J. F. McAllister, the northern Panamint Range and the Funeral Mountains, Calif.; D. C. Ross, the northern Inyo Mountains, Calif.; H. R. Cornwall and F. J. Kleinhampl, Bare Mountain, Nev.; R. K. Hose, the Confusion Range, Utah; and Ronald Willden and R. W. Kistler, the Ruby Mountains, Nev. Corals from the Simpson Park Mountains and the Toquima Range, Nev., were contributed by A. J. Boucot and J. G. Johnson. The writer thanks Helen Duncan and Jean M. Berdan of the U.S. Geological Survey for assistance in connection with Entelophylloides and for material representing this genus collected by them from the Cobleskill and Keyser Limestones. The writer also thanks Prof. S. W. Muller and Stanford University for use of the McAllister thesis fossil col- lections from the northern Panamint Range. All fossil photographs are the work of Kenji Sakamoto of the U.S. Geological Survey. Thin sections used during the last 2 years of this study were prepared by Robert G. Shely. IDENTIFICATION OF THE SILURIAN SYSTEM IN THE GREAT BASIN The Silurian System in the central and eastern Great Basin is part of a fairly continuous saccharoidal dolomite section that includes Late Ordovician and Devonian strata as well. These somewhat monotonous and not in- frequently barren dolomites occupy a stratigraphic interval between the Pogonip Group or the Eureka Quartzite and various horizons of the Middle Devonian. The lowest dolomites of this three-system sequence are readily distinguishable as Late Ordovician. by, a widespread Richmondian brachiopod-coral fauna con- taining abundant streptelasmid and halysitid corals. The top of the Silurian within the upper third of the sequence is less readily distinguishable, for above the uppermost fossil zone of unequivocal Silurian age no diagnostic faunas of Early and early Middle Devonian age have thus far been recognized in the dolomite facies. Most of the well-documented Early Devonian fossils have come from limestone or dolomitic'limestone facies of the west-central and southwest Great Basin. Halysitid corals and large pentameroid brachiopods of the Conchidium and Virgiana types are the commonly accepted criteria of Silurian age in the three-system dolomite succession. Halysitids have been considered more indicative of the lower beds, and the large pentameroids more characteristic of the higher Silurian. In view, however, of the great abundance of halysitids in the Richmondian or Late Ordovician beds, these tabu- lates are not definitive unless identified generically and specifically. Silurian faunas of the Cordilleran belt have received little attention by the paleontologist and stratigrapher. Until recently, scarcity and poor preservation of fossils in dolomite discouraged serious paleontologic study. Routine fossil idenfifications for stratigraphic purposes were always provisional and uncertain-the species assigned with a query to a described fossil of a distant province, and the genera long-ranging and in most instances of doubtful value for system discrimination. Except possibly for graptolites in appropriate facies, there has been almost no paleontologic basis for zoning or stratigraphic subdivision of the Great Basin Silurian; in fact, paleontologic identification of the system itself has in some areas remained in doubt. Thus far, evidence from graptolites is lacking in the prevailingly dolomitic facies of the central and eastern Great Basin. Whereas most of the identified Silurian of the Great Basin is marine dolomite, mapping'in the west-central and southwestern parts of this province discloses areas of Silurian and Early Devonian limestone rich in fossils, of which many of the more distinctive are rugose corals. Northwest of the Great Basin, from the north end of the Sierra Nevada to the Klamath Mountains, there exists a third Silurian stratified rock suite in which siliceous clastic rocks of the graywacke type prevail, and where all carbonate rocks are nondolomitic. In limestone lenses of this graywacke province, the rugose corals are again among the distinctive Silurian indicators. DEPOSITIONAL AND FAUNAL FACIES 5 AREAL DISTRIBUTION OF GREAT BASIN SIL CORAL-BEARING ROCKS Silurian marine rocks of the southwest Cordillera, including the Great Basin, are distributed in three belts, contrasted with respect to lithology and faunas. These belts are the (1) eastern dolomite belt, (2) intermediate limestone belt, and (3) western, or Pacific Border, graywacke belt. Paleogeographically, the boundary trends of these belts are poorly defined, but they appear to have extended across the Great Basin province in north to northeasterly directions (fig. 2), not necessarily in aline- ment with existing orographic features. A border zone between the intermediate limestone belt and the eastern dolomite belt may be fairly accurately delineated in the vicinity of the Inyo Mountains and the Panamint Range, and in the Roberts Mountains and east of the Monitor Range. The boundary relationship of the intermediate limestone belt and the western graywacke belt is inferential, mainly because of cover by younger rocks. Coral faunas in the three Silurian belts differ because of facies and by reason of the vagaries of faunal dispersal and paleogeography. Eastern dolomite belt.-This belt includes Silurian strata of the southern and eastern Great Basin and much of the central part that have been described as Hidden Valley Dolomite, Lone Mountain Dolomite, and Laketown Dolomite. In general terms, these rocks will be referred to hereafter as the Lone Mountain-Laketown facies. Only in the east-central and southwest Great Basin have the coral faunas of the eastern dolomite belt been studied intensively. However, in several mining districts of the eastern Great Basin, Silurian corals are fairly abundant, and provisional generic identifications have been made. Intermediate limestone belt.-In such areas as the northern Inyo Mountains, Toquima Range, Monitor Range, Simpson Park Mountains, and the Roberts Mountains, the Silurian is represented by limestones. These limestone beds have yielded the greater part of the well-preserved rugose coral material herein described. Plotted distribution of limestone occurrences relative to occurrences of the eastern dolomite belt suggests that depositional change from dolomite to limestone took place in a westerly to northwesterly direction. Only in the Roberts Mountains is there evidence of intertonguing of Silurian dolomite and limestone facies, and there the structural conditions related to major thrusting are un- favorable for stratigraphic deductions. Recent discoveries of Silurian coral-bearing beds in the north-central Great Basin are mostly within the intermediate limestone belt, although those in the Ruby Mountains lie on the eastern dolomite side. Western, or Pacific Border, graywacke belt. -In the western Great Basin occurrence of the Pacific Border graywacke belt beneath younger rocks is mainly inferential; the nearest exposures of such beds are at the north end of the Sierra Nevada near Taylorsville, Calif. Ordovician black shales and arenaceous deposits are known in the western Great Basin, and clastic deposition may have persisted into Silurian time in that part of the province. From the Taylorsville area northwest through the Klamath Mountains of northernmost California, the Silurian rocks of the Pacific Border province comprise argillite, graywacke, conglomerate, bedded chert, and fairly pure limestone. There is no dolomite. Much of the graywacke was probably derived from more or less con- temporaneous volcanic rocks. Silurian strata of the Pacific Border graywacke suite are best exposed in southeastern Alaska, where they resemble those of the northern Cali- fornia region. In southeastern Alaska, mafic volcanic rocks with pillow structure are interbedded with the Silurian graywacke. All carbonate rocks are, again, nondolomitic. Silurian rugose coral faunas of the Pacific Border pro- vince differ to a considerable degree from those of the adjoining intermediate limestone belt on the east and probably to a greater extent from those of the eastern dolomite belt. The Rugosa of the Klamath Mountains Sililurian are described in a separate report (Merriam, 1972.) DEPOSITIONAL AND FAUNAL FACIES OF GREAT BASIN SILURIAN CORAL-BEARING ROCKS Two contrasting marine depositional and faunal facies are recognized in many parts of the world where the Ordovician and Silurian Systems are well represented. Faunally speaking, these are referred to in England as the graptolitic facies and the shelly facies (Jones, 1983, p. 474). The graptolitic facies in both geologic systems is com- monly black, ofganic clay . shale: the - shelly facies-characterized by predominance of heavier shelled organisms, such as Mollusca, brachiopods, and the corals-is typified by carbonate rock and marlstone. Facies contrasts of this kind are especially impressive in the Great Basin Ordovician, where black shales, siltstones, cherts, and minor limestones of graptolitic sequences, such as the Vinini Formation, occupy separate outcrop belts and form thrust sheets of exceedingly complex structure. Carbonate shelly facies, being more competent structurally, have been less intensely deformed. In places the two Ordovician facies come together in thrust fault contact. Wholly graptolitic facies of the Silurian, although poorly under- stood, appear to be less extensive than other facies in the Great Basin. Limestone and dolomite, which include shelly facies only, make up the greater part of the known Silurian. Graptolitic facies of this system are mainly calcareous shale and thinly bedded calcareous siltstone that are lithologically unlike the very extensive non- calcareous clay shale, argillite, and chert of the Ordovician graptolitic sequences. In the western part of the Great 6 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN 124° 122" 120° 118° 116° 114° 112° 44° (> W OREGON DPocatello 42° wa Logan Sd Sd Lake own : Salt Lake Clty 40° l 32 Provo) " 1 - sages | 8\°Sd I Sdp / I c "p Eastern dolomltle belt Sd 38° Sd 10 1 15 , [25 | ,\ Intermediate cog I , limestone i \ belt SC}: 1 8 e /‘% besa 3\ | [V a I dependence ) c £ 4 Sia § A 29 |- g qu 6 \Las Vegag, Bakersfield FlagstaffD 1 1 1 1 1 0 50 100 150 MILES FigurE 2.-Major lithologic belts, distribution of Silurian reference sections, and coral localities in the Great Basin. Basin, some of the localized outcrops of Silurian limy shale and platy siltstone yield only graptolites. Other Silurian graptolite deposits are more sporadic, occurring as occasional calcareous shale tongues or interbeds in limestone units wherein the shelly facies predominate. In some areas of almost exclusively graptolitic facies, such as the Ordovician Vinini, it is not improbable that graptolite-bearing clay shale and chert deposition persisted on into Silurian time. Eastern dolomite belt. -Silurian dolomites of this belt (Staatz and Osterwald, 1959) range in thickness from 2,500 feet at Lone Mountain, Nev., to 1,200 feet in western Utah. Thick-bedded blocky gray dolomite of saccharoidal tex- ture is characteristic; most of these dolomites have a rather uniform and monotonous appearance and lack easily recognizable and persistent lithologic changes by which they might conveniently be subdivided into map units. Argillaceous beds are uncommon within the eastern DEPOSITIONAL AND FAUNAL FACIES 7 EXPLANATION © Type areas of Silurian marine rock units Lone Mountain Dolomite Laketown Dolomite Bluebell Dolomite (Silurian part) Hidden Valley Dolomite (Silurian part) Laketown Dolomite: four described members in Thomas Range, Utah Roberts Mountains Formation Masket Shale of Kay and Crawford (1964) Vaughn Gulch Limestone Montgomery Limestone Gazelle Formation Trail Creek Formation f A G b = ~ 5 (o S ~ ® wom Silurian rugose coral genera Late Silurian Toquimaphyllum and related corals Rhizophyllum Entelophyllum Stylopleura Lykophyllids Zelophyllum s 0 © a m ® o Middle Silurian Lykophyllids Zelophyllum p b P Lower Silurian Palaeocyclus Arachnophyllum Dalmanophyllum ® e e o Silurian dasycladacean algae Late Silurian m Verticillopora Middle Silurian a Verticillopora Prevailing lithology Sssl, shale, sandstone, and limestone Sss, shale and sandstone S1, limestone Sd, dolomite Sdq, dolomite and quartzite Silurian localities 1. Mazourka Canyon, northern Inyo Mts dolomite belt; toward the west occur sporadic lenses of clean lime-cemented quartz sandstone or quartzite. Continuous diagenetic dolomite accumulation without significant stratigraphic discontinuity during most of the Silurian suggests a stable marine environment, little disturbed by crustal deformation, under conditions com- monly ascribed to the "stable shelf." $ Fossils are scarce or absent throughout most of the eastern dolomite. Silicified fossil material is locally abundant, especially in scattered bodies of dark-gray carbonaceous dolomite surrounded by the normal, lighter gray rock. Within these highly organic lenses and pockets, corals and brachiopods became silicified early and mysteriously survived destruction during the magnesian recrystallization. Fossil assemblages of these carbonaceous Cerro Gordo area, southern Inyo Mts Ubehebe Peak area, northern Panamint Range Andy Hills, northern Panamint Range Whitetop Mtn., northern Panamint Range Funeral Mts Bare Mtn. area Pahranagat Range Ely Springs Range 10. Sunnyside 11. Dobbin Summit 12. Ikes Canyon 13. Austin area 14. Copenhagen Canyon 15. Southern Fish Creeks Range 16. Southern Mahogany Hills 17. Lone Mountain, Eureka County 18. Southern Sulphur Spring Range 19. Roberts Creek Mountain 20. Coal Canyon, northern Simpson Park Mts 21. Ruby Mts 22. Maggie Creek, Eureka County 23. Antelope Peak, Elko County 24. Pequop Mts 25. San Francisco district 26. Ibex Hills 27. Kings Canyon, Confusion Range 28. Confusion Range, southern part 29. Thomas Range 30. East Tintic Mts 31. Gold Hill district 32. Stockton and Fairfield areas 33. Logan area 34. Randolph area 35. Elbow Canyon 36. Rock Creek, Lost River Range 37. Grouse Creek, Lost River Range 38. Bayhorse quadrangle, east-central part 39. Bayhorse quadrangle, north-central part 40. Bayhorse quadrangle, central part 41. Trail Creek 42. Mount Morrison area 43. Northeast Klamath Mts, Willow Creek area 44. Northeast Klamath Mts, Horseshoe Gulch area 45. Taylorsville area 46. Weaverville quadrangle, Douglas City area 47. Knownothing Creek, Cecilville area, Klamath Mts 0 w co 1 a tr B w ho dolomite lenses differ in character from those in ap- proximately correlative limestone facies of the inter- mediate limestone belt.. Among rugose corals, Entelophyllum is the best known in the eastern dolomite belt; in terms of biofacies the eastern dolomites are referred to as the Entelophyllum facies, as this coral genus is not a common element of the intermediate limestone belt to the west. Intermediate limestone belt. to dark-gray and bluish-gray limestones of this Silurian belt have been traced from the northern Inyo Mountains, Calif., to the Tuscarora Mountains of northern Nevada. Ranging in thickness from 1,200 feet in the Inyos to more than 2,000 feet in the Simpson Park Mountains and the Roberts Mountains, the limestones of this belt are here and there 8 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN rich in well-preserved rugose corals and other fossils. In these facies are to be found the more continuous marine reference sections. Platy and flaggy to thick-bedded lime- stones are characteristic, with relatively few massive members. Bioclastic facies are common; the contributing organisms - are crinoids, - stromatoporoids, _ corals, brachiopods, calcareous algae, and Mollusca, in approximate order of decreasing abundance. Bedded dark- gray chert is widespread at the base of these limestone successions. Calcareous shaly interbeds and partings are most numerous in the lower parts of stratigraphic sequences in the intermediate limestone belt. There is little wholly non- calcareous clay shale in these strata. Graptolites are most obvious to the collector in these lower, shaly inter- calations. The higher and more thickly bedded parts of Great Basin Silurian limestone sequences have thus far yielded relatively few graptolites. Limestones of the intermediate limestone belt contain dolomite tongues in the type section of the Roberts Moun- tains Limestone (Winterer and Murphy, 1960). It is possible that we have here a boundary relationship with the eastern dolomite belt. A lateral interfingering rela- tionship between the coral-rich Vaughn Gulch Limestone of the intermediate limestone belt and graptolitic facies can be observed in Mazourka Canyon, northern Inyo Mountains. There, the Sunday Canyon Formation (Ross, 1966, p. 32), a calcareous but partly shaly graptolitic unit, reveals probable northward tongues of the Vaughn Gulch Limestone, which has yielded no graptolites. No exposures which bridge the gap between facies of the intermediate limestone belt and the Pacific Border graywacke belt are known in the western Great Basin. Rocks of the Pacific Border graywacke belt have thus far disclosed no diagenetic dolomite; coral-bearing lime- stones of this belt are quite subordinate to the siliceous clastics of which the source material is in considerable part volcanic. GREAT BASIN SILURIAN REFERENCE SECTIONS Because of structural complexity and lack of continuous exposure, Silurian rock sequences with depositional contact at bottom and top are a rarity in the central and southwest Great Basin. Faults are the common system boundaries. Hence, vertical and evolutionary order of faunas is partly dependent upon composite sequences, the reliability of which is within the limits of accuracy imposed by physical or fossil correlation between separate, but theoretically overlapping, partial sections. Of. the many Silurian outcrop areas mapped or examined during the course of these studies, few are suf- ficiently inclusive to serve as reference sections for the system. Those so designated within the intermediate lime- stone belt are as follows: The Mazourka Canyon section, northern Inyo Mountains; the Ikes Canyon section, Toquima Range; the Roberts Creek Mountain section; and the section in Coal Canyon, northern Simpson Park Mountains. Reference sections for the eastern dolomite belt are those of the northern Panamint Range near Ubehebe Peak and Whitetop Mountain, the Funeral Mountains section, California, and the Lone Mountain section, Eureka County, Nev. The section at Bare Mountain near Beatty, Nev., may eventually be suitable for reference purposes; like the Roberts Creek Mountain section, it also lies near the border between the eastern dolomite and intermediate limestone belts. MAZOURKA CANYON REFERENCE SECTION At Mazourka Canyon a continuous limestone sequence about 1,500 feet thick rests conformably upon the Late Ordovician Ely Springs Dolomite and is overlain disconformably by Mississippian conglomerate and quartzites (fig. 3). Named the Vaughn Gulch Limestone by Ross (1963, p. B81), this formation has been a subject of paleontological investigation since 1912, at which time these strata were considered to be Devonian (Kirk, 1918; Stauffer, 1930). Mapping of the Cerro Gordo mining district in 1946 brought renewed interest in these beds, when it became fairly evident that the Silurian and Lower Devonian Hidden Valley Dolomite (McAllister, 1952) of the southern Inyo Mountains near Cerro Gordo changes northward into limestone (Merriam, 1963a). Rugose coral studies of Vaughn Gulch material from what is now called coral zone E indicated correlation with coral faunas in central Great Basin Silurian limestones. The Vaughn Gulch Limestone appears to be an unbroken sequence of well-bedded medium- to dark-gray, partly bluish-gray, impure carbonaceous limestone, argil- laceous limestone, and calcareous siltstone, including many fossil-rich beds. Some of the more argillaceous and silty interbeds weather in subdued fashion to a light gray, stained pink or orange in places. Black chert zones are stratigraphically significant, occurring at the base and top of the formation; elsewhere, minor chert is present as scattered nodules or thin lenses. Platy and flaggy ex- posures predominate, with limestone beds ranging in thickness from 1 to 6 inches separated by calcareous shaly or siltstone partings. Thicker limestone beds, some more than 3 feet thick, are fairly common, and many of them are bioclastic. These weather out prominently and are the most numerous in the upper middle part of the formation. Readily mappable lithologic divisions (Ross, 1965, 1966) have not been recognized within the Vaughn Gulch Limestone. For faunal distribution, however, the column can be divided into a lower part 350 feet thick, a middle part 720 feet thick, and an upper part 460 feet thick. More uniformly bedded and having fewer bioclastic and fossil beds than higher parts of this formation, the lower 350 feet consists largely of platy to flaggy, partly laminated dark-gray or bluish-gray argillaceous limestone that GREAT BASIN SILURIAN REFERENCE SECTIONS Type section of Vaughn Gulch Limestone 1530 ft Pg Middle unit ; 5|$ 720 ft essay C NS» g $3 SJP coral | | Coral zone g g € zone | § 1 A Ely Springs| Eureka Quartlzite Pogonip Group equivalent2 F3 f 5 g E )| S| I € Dolomite equivalent r Upper unit 3 Verticillopora beds =/ I & 275 ft 380 ft i 7 460 ft T| Toquima-| oJ. |! a 3 5| Upper Silurian or phyllum | P S=) || § c|.§ .5 s 3 | Lower Devonian $o §] g g § 8/9 2 o E 2C E c € ® Els 2)2 0 6 6 of P z c s|8g p4 C & 5s s &! 53 S2 $]0 6 3 s| g § = i% - & 3 ©| 8 6|g a. 3 pB ede 3 4800' a. 4700" z? 4600' 0 200 lBarrel Spring and Johnson Spring are local names (Ross, 1966) applied to units of the Eureka Quartzite interval; normal Eureka Quartzite occupies this interval along the west Inyo Mountains front 15 miles to the south (Merriam 1963a). Ranges from Middle to possibly Late (Richmond) Ordovician age. 400 FEET 2Local names have been given to these strata (Ross, 1963, 1966). 3Disconformity at top of Vaughn Gulch Limestone (Merriam, 1963a, p. 15). FIGURE 3.-Mazourka Canyon reference section, showing type section of the Vaughn Gulch Limestone. Section extends northeasterward along divide between Vaughn Gulch and Willow Springs Canyon, Indepencence quadrangle, California. Based on unpublished geologic mapping by Merriam. weathers light gray in places. A persistent dark-gray chert member at the bottom, some 15 feet thick, corresponds to that forming the base of the Silurian System elsewhere in the Great Basin. Weak partial dolomitization and nodular chert decrease upward to the lowest fossil bed of coral zone A, which lies 130 feet above the thick basal chert. The few fossil beds in this division contain abundant Heliolites and favositids; more distinctive zone indicators, such as Dalmanophyllum, are uncommon. The 720 feet of limestone constituting the middle part of the Vaughn Gulch includes the prominent medium- to dark-gray richly fossiliferous coralline and bioclastic beds in its upper half, of which the uppermost 200 feet falls within Great Basin Silurian coral zone E. The thicker, darker gray beds, ranging in thickness form 10 inches to more than 3 feet, are generally the biogenic beds; these are commonly sculptured into prominent ribs separated by subdued intervals of silty or argillaceous limestone that weather lighter gray. Crinoidal debris is much of the bioclastic material of these thicker fossil ribs. Some of the fossils which weather in relief are complete but are partially silicified and limonite impregnated. Below the middle of this 720-foot division, most of the limestones are thinner bedded and show fewer bioclastic members. No fossil accumulations with true biohermal relief were found. Chert is a minor constituent. About 300 feet of beds in the middle of this 720-foot division contain an abundance of the large dasycladacean alga Verticillopora. Though long-ranging, these calcareous algae appear to be most numerous in Great Basin Silurian coral zone D. A 460-foot upper interval of the Vaughn Gulch includes those beds between the top of Silurian coral zone E and the Mississippian disconformity. Bioclastic beds within the topmost 75 feet contain abundant poorly preserved fos- sils. Contorted layers of dark-gray chert in the upper 30 feet are associated with massive dark-bluish-gray crinoidal limestone which contains silicified, partly macerated, limonite-stained brachiopods, favositids, and large rugose corals, both solitary and colonial. Below the upper beds, the limestone is partly laminated and platy down to the lower strata adjoining coral zone E, where thicker bic- clastic and coralline beds become more numerous. As noted elsewhere under correlation, there is inconclusive paleontologic evidence of Early Devonian age for the 460- foot upper interval. IKES CANYON REFERENCE SECTION Silurian limestone, calcareous shale, and siltstone some 500 feet thick at Ikes Canyon, northern Toquima Range, Nev., are rich in well-preserved coral material at several stratigraphic horizons. Mapping by Kay and Crawford (1964) shows this area to be structurally very complex; measurable stratigraphic sections are uncommon because of the many thrust and normal faults. Fairly abrupt facies 10 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN changes from graptolite-bearing calcareous shale to shelly facies and coralline limestone further complicate strati- graphic and structural interpretation. The strata in question were assigned by Kay and Crawford (1964, p. 437-441) to the Masket Shale and Diana Limestone of Silurian age, and the McMonnigal Limestone was assigned to the Devonian. Fossil collections upon which Merriam's appraisal is based came from the west side of Copper Mountain, north of Ikes Canyon, where coral-bearing medium- to dark- bluish-gray limestones crop out at successive horizons across strata mapped by Kay and Crawford as Masket, overlain by McMonnigal. The lower coral collections representing Great Basin Silurian coral zones A and D came from sites within the Masket; the upper collections, those of coral zone E, appear to fall within the McMonnigal. Appraisal of Silurian and Ordovician stratigraphy at Ikes Canyon suggests that the upper chert member of Kay and Crawford's (1964, p. 487) prevailingly dolomitic Gatecliff Formation beneath the Masket is actually the widespread Great Basin basal Silurian chert, whereas the underlying dolomitic members of the Gatecliff corres- pond to the Ely Springs Dolomite of Late Ordovician (Richmondian) age. ROBERTS CREEK MOUNTAIN REFERENCE SECTION The Roberts Creek Mountain reference section is 1% miles west-northwest of the summit of Roberts Creek Mountain on the spur between the north and middle forks of Pete Hanson Creek. The type sections of the Late Ordovician (Richmondian) Hanson Creek Formation and the conformably overlying Roberts Mountains Formation of Silurian age are included. About 2,200 feet thick, the Roberts Mountains Formation is approximately 80 percent limestone with a prominent cherty member at the base and dolomitic lime- stone and dolomite beds in the upper 450 feet (fig. 4). Stratigraphic relationships are clearly shown in the lower 1,500 feet of this column; the higher part, being closer to the Roberts Mountains thrust, is more deformed, and the beds in this direction become increasingly more dolomitic. The Roberts Creek Mountain reference section was measured in 1934 (Merriam, 1940) and has more recently been mapped by Winterer and Murphy (1960, p. 120) in connection with study of intertonguing dolomite and limestone. In the immediate type area, lithology and paleontology make feasible a three-unit division as unit 1 (180 ft), unit 2 (1,100ft), and unit 3 (900 ft), in ascending stratigraphic order. Unit 1, a chérty division, comprises a basal chert overlain by fine-textured thin-bedded or laminated dark-gray limestone that weathers platy and flaggy with shaly partings. The limestones weather light gray. The distinctive basal chert is bluish black; its lowermost 10 feet is 75 percent chert containing subordinate limestone lenses. The chert decreases upward, occurring in % to 2- inch layers separated by laminated limestone. The chert largely disappears toward the top of unit 1. The basal chert, conformable with underlying Hanson Creek Formation, is the widely recognized basal chert of the Great Basin Silurian. Fossils are scarce in the laminated limestone, but shaly partings yield poorly preserved graptolites. In other areas correlative basal cherts contain pentameroid brachiopods. Unit 2 comprises platy to flaggy dark, sometimes bluish-gray, limestones and heavier limestone interbeds up to 2 feet thick. Calcareous shaly partings separate the limestone layers, many of which are coarse textured and highly fossiliferous, much of the debris being crinoidal. The absence of chert and the introduction of the thicker, coarsely bioclastic and crinoidal beds distinguish unit 2 from unit 1. Scattered black chert lenses are, however, present above the middle of unit 2. In the upper part are a few light-gray recrystallized carbonate layers that appear to be somewhat dolomitic. Tabulate corals and pentameroids and other brachiopods are abundant in the many bioclastic beds, but rugose corals are in the minority. Unit 3 is gradational with unit 2 through an interval in which the coarser textured crinoidal layers containing abundant Conchidium-like brachiopods pass upward into a thicker bedded sequence of light- and dark-gray blocky weathering limestones which include coralline beds. These coral beds contain large colonial Rugosa and represent Great Basin Silurian coral zone C. Some 250 feet above the base, this unit becomes prevailingly lighter gray and less well bedded as it passes into the magnesian lime- stone and dolomite of the upper half. Light-gray weather- ing magnesian limestones in the middle part of this unit contain abundant silicified corals of Great Basin Silurian coral zone D. Bedding is poorly defined and blocky through the upper 400 feet, where fossils become fewer and the rock passes into dolomite of the overlying unit. Some 1,600 feet of blocky dolomite between unit 3 and the richly fossiliferous beds of the Devonian Nevada Formation were initially correlated with the Lone Mountain Dolomite (Merriam, 1940, p. $2). No identifiable fossils were obtained from this interval. It probably includes not only a partial equivalent of the Lone Mountain but also higher dolomitic limestones and dolomites which elsewhere represent the lowermost Nevada containing the Helderbergian Rabbit Hill fauna and faunas of Oriskany age. COAL CANYON REFERENCE SECTION The Coal Canyon reference section, at the north edge of the northernmost Simpson Park Mountains, includes 5,000 feet of east-dipping strata ranging in age from Late Ordovician to Middle Devonian. Along the east slopes of Coal Canyon near its mouth are the best known exposures GREAT BASIN SILURIAN REFERENCE SECTIONS 11 C Eureka | Hanson Creek Roberts Mountains 5 Undifferentiated _ |G Nevada Formation g Quart-| Formation Formation § Lone Mountain g g zite 650 ft 2180 ft ~ Dolomite and 3 s 500 ft y § . & Beacon Peak e e 5 5 Unit 1 Unit 2 Unit 3 2) Dolomite Member |& Roberts Creek (€.. .0 0 180 ft| 1100 ft 900 t: 5 of Nevada e sy ; he] 3 3 ; 3 10,000 3 o 8 Formation 3 6 6 s .- Coral zones a s 9 | 2 6 € C D é E gs 8 9219 ft 6 5 man a 9000 ci ZC bs 5 |.C ps 8233 ft 2 |p / 8000' Direction of structure section S 80° E 0 1000 FEET lUpper 500 feet of this undifferentiated dolomite may include the Beacon Peak Dolomite Member of the Nevada Formation, which 10 miles east in the Sulphur Spring Range contains the Rabbit Hill fauna of Helderberg Early Devonian age. % 2 Expected position of Great Basin Silurian coral zone E; corals of this zone absent possibly because of dolomite facies. Acrospirifer kobehana and Eurekaspirifer pinyonensis faunas in Nevada Formation of lower plate below Roberts Mountains thrust. FIGURE 4.-Roberts Creek Mountain reference section, showing type section of the Roberts Mountains Formation and type section of the underlying Hanson Creek Formation. Section extends S. 80° E. between south and middle forks of Pete Hanson Creek, Roberts Creek Mountain quadrangle, Nevada. of uppermost Roberts Mountains Formation in normal stratigraphic contact with overlying Rabbit Hill Limestone of Early Devonian age. The strata of this section probably occupy the lower plate of an overthrust. One-half mile southeast of the mouth of Coal Canyon, a flat-lying discordant outcrop of brecciated Ordovician Vinini chert and shale probably represents the upper plate of the thrust. All strata of this area are cut by later north- trending high-angle faults which exert topographic control and hamper measurement of continuous stratigraphic sections. A north-trending shear zone along the west side of Coal Canyon is several hundred feet wide and separates the less disturbed upper beds of the Roberts Mountains Formation along the east wall of the canyon from the dislocated limestone and calcareous shale of probable Silurian age to the west. On the east of the canyon, the uppermost 250 feet of the Roberts Mountains Formation below the Rabbit Hill boundary comprises flaggy to thick-bedded dark-bluish-gray limestone containing lenses and interbeds of coarse depositional limestone breccia (Winterer and Murphy, 1960). Clasts and matrix of these breccia bodies contain well-preserved corals and brachiopods representing Silurian coral zone E. of this report. The Roberts Mountains-Rabbit Hill contact is drawn where the thicker coralline beds and lenses of Silurian coral zone E pass upward into thinner bedded and platy, somewhat darker gray limestone and calcareous shale of the Rabbit Hill. This boundary appears to be gradational and is without recognized features of disconformity, such as might be expected along a tradational system boundary. The Helderbergian Rabbit Hill of this eastern structural block has a minimum thickness of 900 feet. Allowing for probable duplication of Rabbit Hill strata by faulting, the total width of outcrop, which exceeds half a mile, suggests that this formation may be more than 1,000 feet thick in this area. The easternmost and stratigraphically uppermost exposures in the Coal Canyon section are the argillaceous limestones of Merriam's Nevada Formation unit 2 (Merriam, 1973c). Alluvial cover prevents determination of true stratigraphic relationship of the Rabbit Hill Limestone to the contiguous Nevada. No strata of the Early Devonian (Siegenian) unit 1 of Merriam (1973¢) of the Nevada Formation were recognized. The Roberts Creek Mountain stratigraphic section appears fairly continuous in the structural block west of the Coal Canyon shear zone. Johnson and Murphy (1969) used the name "Windmill Limestone" for upper beds of this block and have included in this unit not only the Coal Canyon shear zone but also the uppermost Roberts Mountains Formation below the Rabbit Hill contact in the contiguous eastern structural block. Johnson and Murphy (1969, fig. 2) regarded their Windmill Limestone as Early Devonian on the basis of somewhat controversial evidence from graptolites, conodonts, and brachiopods. This rugose coral investigation, together with concurrent detailed geologic mapping of the Coal Canyon area by Merriam, fails to support the conclusions of Johnson and Murphy (1969) with respect to Devonian age assignment of the uppermost Roberts Mountains Formation in this reference column. Clearly, the 12 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN "Quadrithyris zone' of Johnson and Murphy is Merriam's Silurian coral zone E, which contains here, as elsewhere in the Great Basin, a large and distinctive rugose coral assemblage of Gotlandian character. Rationalization of this question should await the completion of detailed geologic mapping in this area. Other structural and paleontologic problems engendered by the Johnson- Murphy stratigraphy call for review of fossil identifica- tions and fossil ranges. As presently interpreted by these workers, the lower part of their Windmill Limestone, dated as Early Devonian by species of Monograptus (M. hercynicus and M. praehercynicus) with support from conodont and brachiopod evidence, underlies their "Quadrithyris zone," which brackets Merriam's Silurian coral zone E. The Coal Canyon reference section supplements the type section of the Roberts Mountains Formation 12 miles to the southeast (Merriam, 1940, p. 11). Both occupy structural belts of thrusting and subsequent high-angle faulting. In detail the two sections present both similari- ties and differences. Dolomite, present as tongues and interbeds in the type section, has not been found at Coal Canyon, whereas the coral-rich depositional limestone breccias of Coal Canyon are unrecognized in the type section of the Roberts Mountains Formation. Graptolitic facies are better shown and probably more extensive in the Coal Canyon Silurian. Most noteworthy is the failure to recognize the Helderbergian Rabbit Hill beds where they are to be expected above the type Roberts Mountains Formation on Pete Hanson Creek. However, in this section these Helderbergian strata may well be represented in the thick dolomites occupying the interval between the Silurian Roberts Mountains beds and the Devonian Nevada Formation at Roberts Creek Mountain. NORTHERN PANAMINT RANGE REFERENCE SECTION The Silurian strata of the northern Panamint Range reference section are a part of the Hidden Valley Dolomite in its type locality 2% miles north of Ubehebe Peak (McAllister, 1952, p. 15). There, the Hidden Valley is 1,365 feet thick and rests conformably upon Late Ordovician (Richmondian) Ely Springs Dolomite. In neighboring areas to the east, higher beds of this dolomite formation contain Early Devonian (Oriskany) fossils. Only Silurian fossils are known in the type area, and a system boundary cannot be indicated within the unbroken sequence. McAllister (1952, p. 15, 16) defined three lithologic units. Only in the lower unit, or unit 1, having a thickness of 485 feet, are Silurian fossils abundant. The thick-bedded saccharoidal dolomites of this division weather blocky and medium to light gray and are cherty. Coral-rich beds of Great Basin Silurian coral zone B occur in the upper part of unit 1, about 300 feet above its base. Few fossils have been found in the 730 feet of dolomite in overlying unit 2. A faulted Hidden Valley Dolomite sequence at Whitetop Mountain, 10 miles northeast of the type section, shows the lowermost beds of unit 1, which contain the fauna of Great Basin Silurian coral zone A. A similar zone A assemblage was collected by McAllister in the Andy Hills 6% miles east of the type locality. Thus far, the Early Silurian zone A fauna has not been found below coral zone B, where it would be expected, in the lowermost dolomites of the Hidden Valley in its type locality. LONE MOUNTAIN REFERENCE SECTION The Lone Mountain Reference section is on the south- west side of Lone Mountain, Eureka County, Nev., where the entire carbonate sequence from the top of the Eureka Quartzite to the base of the Nevada Formation of Devonian age is diagenetic dolomite. Detailed geologic mapping of Lone Mountain, which is within the type area of the Lone Mountain Dolomite, was carried out under the Kobeh Valley project of Nolan and Merriam; this mapping called for stratigraphic revision, in accordance with which the name Lone Mountain Dolomite is applied to the entire 2,500 feet of section from the bottom of the Silurian basal chert directly overlying the Hanson Creek Formation to the base of the Nevada Formation. Merriam's (1940, p. 18, 21) earlier redefinition of Hague's (1892, p. 57) Lone Mountain Limestone had used the term Roberts Mountains Formation for the lower 750 feet of darker weathering dolomite now designated as Lone Mountain unit 1. Thus revised and reapportioned (fig. 5), Hague's original Lone Mountain Limestone comprises, at the bottom, a Late Ordovician dolomitic facies of the Hanson Creek Formation, overlain by unit 1 and unit 2 of the Silurian Lone Mountain Dolomite. Stratigraphy and paleontology of the Lone Mountain Dolomite are treated in a separate paper (Merriam, 19782). Approximately 80 feet thick in places, the lower chert member of Lone Mountain unit 1 is much thicker than usual for the basal Silurian chert in limestone facies; to- gether, the basal chert and the overlying darker gray saccharoidal dolomite total about 750 feet thick. Although barren of identifiable fossils, Lone Mountain unit 1 probably correlates with the basal chert and limestone of Roberts Mountains Formation unit 1 and part of unit 2 in the richly fossiliferous Silurian limestone facies of the Roberts Mountains area to the north. Lone Mountain Dolomite unit 2, having a thickness of about 1,750 feet, is lighter gray, more massive, and blockier weathering than unit 1. Although coarse saccharoidal texture is characteristic of unit 2, the finer textured dolomite members occur toward the top. In the type section, Lone Mountain Dolomite unit 2 appears to be gradational with the overlying, richly fossiliferous dolomitic Lower Devonian sandy limestone of Nevada Formation unit 1. No trace of the Helderbergian Rabbit Hill fauna has been found where it would be expected near this boundary. RUGOSE CORAL ZONATION OF THE GREAT BASIN SILURIAN 13 Hague (1892) Merriam (1940) Merriam (this report) Nevada Limestone Nevada Formation Nevada Formation Early Devonian unit 1 (early Emsian) Lone Mountain Formation (restricted) Lone Mountain Dolomite unit 2 Silurian } Lone Mountain Limestone Roberts Mountains Formation (dolomite facies) Hanson Creek Formation (dolomite facies) Lone Mountain Dolomite unit 1 Hanson Creek Formation (dolomite facies) Eureka Quartzite Eureka Quartzite Ordovician Eureka Quartzite ¢ All known fossils of the Lone Mountain Dolomite type area are Silurian. * Silurian basal chert marker. FIGURE 5.-Comparative diagram illustrating present usage of the stratigraphic name Lone Mountain Dolomite in its type area. Fossils are scarce and very poorly preserved because of magnesian recrystallization through the Lone Mountain Dolomite type section. In the upper 500 feet of unit 2, scattered very dark gray carbonaceous dolomite lenses contain fairly abundant but fragmentary and partly macerated colonial rugose corals probably of the Silurian genus Entelophyllum, a common and well-Ereserved silicified fossil in neighboring Lone Mountain Dolomite exposures. Supplementary Lone Mountain exposures yielding Entelophyllum and well-preserved Silurian brachiopods have recently been mapped in the Mahogany Hills, 16 miles southeast of Lone Mountain, and in the Fish Creek Range, 25 miles southeast of Lone Mountain. Other outcrops of Lone Mountain Dolomite have been mapped in the southern Sulphur Spring Range, 20 miles northeast of Lone Mountain. There, the large dolomite fault block of East Ridge, near Romano Ranch, contains Silurian coral faunas probably representing lower horizons of the Lone Mountain Dolomite. As discussed below under correlation of Great Basin Silurian coral zones, the higher Lone Mountain in the Mahogany Hills and the Fish Creek Range pertains to the Late Silurian upper Lone Mountain-Laketown Dolomite faunal facies. In the Sulphur Spring Range, the large East Ridge dolomite fault block near Romano Ranch includes about 1,200 feet of blocky Lone Mountain with two coral horizons-one about 250 feet above the base, and the other 504-634 O - 73 - 2 near the top. Abundant Halysites - and Silurian Pycnostylus (pl. 15, fig. 11) and Stylopleura? (pl. 16, figs. 3, 4) occur in these horizons. These dolomites may be partly correlative with Lone Mountain unit 1. In a separate fault block west of the East Ridge block occur dolomitic lime- stones with a Helderbergian Rabbit Hill fauna. These beds lie above the Lone Mountain Dolomite at the base of Nevada Formation unit 1 (Merriam, 1973a). Mapping of these dolomitic Helderberg beds in the Sulphur Spring Range has led to the conclusion that they are correlative with the Beacon Peak Dolomite Member, the lowest member of the Nevada Formation in the Eureka mining district (Nolan and others, 1956, p. 38). Southeast of Eureka in its type section, the fine-textured Beacon Peak is separated from coarse-textured subjacent Lone Mountain Dolomite by a sharply incised undulant erosion surface unrecognized in the type section of the Lone Mountain Dolomite. RUGOSE CORAL ZONATION OF THE GREAT BASIN SILURIAN Study of the stratigraphic distribution of Silurian Rugosa in correlative and overlapping reference sections makes possible a hypothetical fivefold paleontologic zonation based on ranges of species and genera. Provisional zones are designated by capital letters A through E, in ascending stratigraphic order. Gaps in the coral record within a single reference section may be filled 14 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN in the correlative sections to complete the overlapping composite zonal scheme. At present, no more than three coral zones have been recognized within any one reference column; additional collecting is expected to eliminate some of these local gaps. Ranging in age from late Early to Late Silurian, the five coral zones are as follows: Great Basin Age Silurian British Series coral zone E Late Silurian Ludlovian D C Middle Silurian Wenlockian B Late Early Silurian A Late Llandoverian As noted elsewhere, there is inconclusive evidence of biofacies or ecologic difference between the rugose corals in diagenetic dolomite and those in approximately correlative limestone deposits. Rugosa of the upper part of the Lone Mountain Dolomite and of the Laketown Dolomite are, in a biofacies sense, unlike those of the more or less equivalent limestones and cannot, therefore, be included at present in the fivefold zonal arrangement. Silurian coral zone A is based on rugose coral genera present in both dolomite and limestone facies, as well as on forms collected only in the dolomites (fig. 6). Coral zone B assemblages have been collected only in the dolomites. Coral zones C and E are established on the basis of limestone faunas, whereas coral zone D indicators have been found in both carbonate facies. ZIONE A Early Silurian faunas of coral zone A occupy lower beds of the Hidden Valley Dolomite in the reference section of the northern Panamint Range. These are the lowest known Silurian shelly faunas of the Great Basin, occurring in the lower 100 feet of Hidden Valley unit 1 and above the Ely Springs Dolomite with a Richmondian fauna. Rugose corals in basal Silurian beds of Whitetop Mountain, northern Panamint Range, are as follows: Rhegmaphyllum sp. h Dalmanophyllum sp. A Palaeocyclus porpita subsp. mcallisteri Rhabdocyclus sp. d Arachnophyllum kay: Other diagnostic Rugosa present in limestone facies coral zone A of the Toquima Range are Cyathophylloides ferguson: and Neomphyma crawfordi, there in association with Arachnophyllum kayi. Palaeocyclus, a small button coral, is the distinctive fossil of this zone. However, it seemingly has facies-restricted distribution, having been collected only in dolomites of the Panamint Range, the Characteristic Rugosa of the Great Basin Silurian coral zones Great Basin Silurian coral zone Characteristic rugose corals of Age Amati Great Basin Siluriar Stylopleura berthiaumi, n. gen., n. sp. Stylopleura nevadensis, n. gen., n. sp. Mucophyllum oliveri, n. sp. Kodonophyllum mulleri, n. sp. Rhizophyllum cl. R. enorme Rhizophyllum sp. D > E Chonophyllum simpsoni, n. sp. Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. Kyphophyllum nevadensis, n. sp. Salairophyllum?* sp. Late Silurian Stylopleura berthiaumi, n: gen., n. sp. Tryplasma duncanae, n. sp. D Tonkinaria simpsoni, n. gen., n. sp. Denayphyllum denayensis, n. gen., n. sp. Tryplasma newfarmeri, n. sp. C Entelophylloides (Prohexagonaria) occidentalis, n. subgen., n. sp. Small streptelasmid corals Brachyelasma sp. B Ryderophyllum ubehebensis, n. sp. B Pycnactis sp. k Petrozium mecallisteri, n. sp. Middle Silurian Rhegmaphyllum sp. h Dalmanophyllum sp. A Cyathophylloides fergusoni, n. sp. Palaeocyclus porpita subsp. meallisteri, n. subsp. A Rhabdocyclus sp. d Arachnophyllum kayi, n. sp. Neomphyma crawfordi, n. sp. Early Silurian * Salairophyllum? material from uncertain stratigraphic horizon at Coal Canyon, Simpson Park Mountains, Nev., probably from beds in coral zone E. Ruby Mountains of north-central Nevada, and the Confusion Range of western Utah. Tabulate corals, thus far unstudied, are the common corals of Silurian coral zone A. These include massive favositids, Cladopora, Heliolites, and Halysites. Silicified brachiopods associated with this assemblage are assigned to Dicaelosia, Dalmanella, Camarotoechia, and Atrypa. Of the Rugosa in coral zone A, only Arachnophyllum and Neomphyma are known in strata above the Lower Silurian, but in regions other than the Great Basin. Cyathophylloides is more commonly a Late Ordovician genus. ZIONE B Of early Middle Silurian age, coral zone B includes the following Rugosa; Small streptelasmid corals Brachyelasma sp. B Ryderophyllum ubehebensis Pycnactis sp. k Petrozgium meallisteri Corals of zone B are known in dolomites of the Great Basin Silurian reference sections north of Ubehebe Peak, Panamint Range, and in the Funeral Mountains. At the ~ RUGOSE CORAL ZONATION OF THE GREAT BASIN SILURIAN 15 Great eae? Basin Characteristtf Location of reference sections, Silurian coral zones, Saga?“ ruggrfsrgora central and southwest Great Basin Geologic |__zones age 1 2 3 4 5 6 Northern Northern Toquima _Northern Roberts Mts, Fish Creek Panamint Inyo Mts, Range, Nev. | Simpson Park Nev Range, Nev. Range, Calif. Calif. Mts, Nev. Australophyllum c o (Toquimaphyllum} hgh Mucophyllum E E = E Rhizophyll 6 | at. $$ Entelo- Che hyll (> o Xyprephy lum 3 38 phyllum £ Stylopleura S facies e § € e Stvlople © o -= ge D Tgnzfnlerliza a C 5 D a: D D 8 ECs 09 GE Tryplasma 5 S E E 'E f B to C E £ £ s 8 6 6 6 < < 2 E u. L. I fe) .S vg "J « w g o 5 Entelophylloides £ .£ C = a z (Prohexagonaria) 'C 5 © 'o 0 C 71 w C Tryplasme £ a E E LL. fol Denayphyllum _° 2 3 w C 3 fe] O 0 a 3 3 o € S S 'o C Ces € 3 < , f > w € = a." & § § s s Fetrozi ~ 8 [+] B T > B > e G < -I Brachyelasma c CC CC 2 Palaeophyllum © as C 9 3 e Palaeocyclus C CC P- Dalmanophyllum e Arach hyll F A N tie A A Brachyelasma FIGURE 6.-Great Basin Silurian coral zones and common rugose coral genera and subgenera. former locality in the type area of the Hidden Valley Dolomite, the zone B fauna occurs in McAllister's (1952, p. 15) unit 1, about 325 feet above the base of the formation. Tabulates are the abundant fossils, as in coral zone A. These include Halysites, Heliolites, and Syringopora. The halysitids are diverse, ranging from the large Halysites (Cystihalysites) of the magnitubus type to species with medium and small corallites. Brachiopods are relatively scarce; only the genus Atrypa has been recognized. Dasycladacean algae first make their appearance in coral zone B, where they are represented in some abundance by a species of Verticillopora with narrow shaft; these do not attain the large size of the Verticillopora in coral zone D. ZONE C Coral zone C of late Middle Silurian age is characterized by the following Rugosa: Denayphyllum denayensis Tryplasma new farmeri Entelophylloides (Prohexagonaria) occidentalis Coral zone C is proposed for the richly coralline beds near the base of unit 3 of the Roberts Mountains Formation (fig. 4) in the type section of that formation on Pete Hanson Creek. No associated brachiopods or other fossils were found in these beds. IONE D Great Basin Silurian coral zone D of Late Silurian age includes the following rugose corals: Stylopleura berthiaumi Tryplasma duncanae Tonkinaria simpsoni The reference section for this zone is also the type sec- tion for the Roberts Mountains Formation on Pete Hanson Creek (fig. 4), where these corals and associated tabulates and brachiopods occupy dolomitic limestones in the upper 250 feet of unit 3. Beds of coral zone D lie about 500 feet above coral zone C in the same section. Between the two intervals this section is penetrated by mafic dikes, but it appears to be otherwise unbroken; toward zone D the limestones become progressively more dolomitic, passing upward into a thick blocky dolomite unit. All fossils obtained in coral zone D are silicified. Predominant in the coral beds are massive and digitate favositids, followed in order of abundance by Rugosa, brachiopods, and calcareous algae. Among the silicified brachiopods pre- pared by acid etching are Dicaelosia, Homoeospira, Kozlowskiellina, and Atrypa. One of the more distinctive elements of the coral zone D assemblage in this section is the dasycladacean alga Verticillopora. ZIONE E Uppermost of the five zones is coral zone E of Late Silurian age, which is characterized by the following Rugosa: Stylopleura berthiaumi Stylopleura nevadensis 16 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Mucophyllum oliveri Kodonophyllum mulleri Rhizophyllum cf. R. enorme Chonophyllum simpsoni Australophyllum (Toquimaphyllum) johnsonii Ryderophyllum? sp. Cyathactis? sp. Coral zone E is proposed for the diverse assemblage occurring in the uppermost beds of the Coal Canyon reference - section, northernmost: Simpson - Park Mountains. The zone fossils come from a limestone interval which includes bodies of breccia-conglomerate; some were extracted from clasts of the depositional breccia. Other than Rugosa, the common fossils of coral zone E. at Coal Canyon are stromatoporoids, massive Favosites with medium and small corallites, chaetetids, Alveolites, and Cladopora. Much of this limestone is bioclastic, is dark, slightly bluish-gray, and contains abundant crinoidal debris and large columnal segments. Well- preserved silicified brachiopods prepared by acid etching are as follows: Orthostrophia sp. Schellwienella? sp. Barrandella? sp. Sicorhyncha? sp. Rhynchospirina sp. Plectatrypa? sp. Atrypa? sp. Kozlowskiellina sp. Meristella sp. The large dasycladacean alga Verticillopora is present but very uncommon in coral zone E at Coal Canyon. Other than fossils removed from breccia clasts or the limestone in place, most collections made on this outcrop band are surface weathered material and float, some of which may be derived from upslope overlying exposures of the Early Devonian Rabbit Hill Limestone. Surface rubble of this kind, which cannot with full assurance be ascribed to coral zone E, yielded the following fossils: Orthostrophia? sp. Cymostrophia sp. Rafinesquina sp. Howellella? sp. Atrypa? sp. Leonaspis sp. Harpid trilobite Proetid trilobite Phacopid trilobite Orthoceras-like cephalopod Conocardium sp. Leperditia sp. (large) Large crinoid columnals and abundant crinoid debris A complex solitary rugose coral (pl. 12, figs. 6-8) placed provisionally in the Russian genus Salatrophyllum was collected at Coal Canyon locality M1117 and was probably derived from uppermost beds of the Roberts Mountains Formation, Silurian coral zone E. This coral resembles an undescribed species from Kuiu Island, southeastern Alaska, where it occurs at locality M1186 with the Late Silurian Conchidium alaskense. The subgenus Toquimaphyllum is the most diagnostic fossil of coral zone E, occurring at all sites where this zone has been recognized. At Ikes Canyon in the Toquima Range, Toquimaphyllum is associated with large phaceloid Kyphophyllum, found also in coral zone E. of the Mazourka Canyon reference section. Coral zone E. is known only in the intermediate limestone belt of the Great Basin. STRATIGRAPHY AND RUGOSE CORALS OF THE LONE MOUNTAIN AND LAKETOWN DOLOMITE The Lone Mountain Dolomite of the central Great Basin and the Laketown Dolomite of the eastern Great Basin are comparable lithologic units in which silicified fossils occur sporadically, most exposures being devoid of identifiable material. Stratigraphy and fossils of the Lone Mountain are dealt with in a separate contribution (Merriam, 1973a). In the eastern Great Basin where Silurian limestone facies are as yet unknown, the term Laketown Dolomite has been applied locally to most of the rocks believed to be of Silurian age. Possible time-stratigraphic equivalence of the entire Laketown to the entire Lone Mountain in its type area as redefined herein remains unsupported by paleontologic evidence. Like faunas of the Lone Mountain those of the Laketown Dolomite seemingly represent biofacies differing from those of Great Basin Silurian limestones in which the fivefold rugose coral zonation here proposed is best shown. Fossils and stratigraphy of both Silurian dolomite formations are at present insufficiently known for coral zoning. Equivalence of the upper part of unit 2 of the Lone Mountain Dolomite to upper beds of the Laketown is convincingly supported by occurrence in both of the Howellella pauciplicata brachiopod fauna, the precise stratigraphic position of which is established in unit 48 (fig. 7, col. 10) of the Confusion Range, Utah, strati- graphic column (R. K. Hose, written communs., 1954-64). These correlative Silurian dolomites are referred to faunally as upper Lone Mountain-Laketown biofacies. Fossils of this biofacies have not been recognized in Silurian limestones. Adjacent to the Lone Mountain Dolomite type area, strata in the upper 500 feet of this formation contain faunas of the upper Lone Mountain-Laketown biofacies with the Silurian rugose coral Entelophyllum. At Lone Mountain itself, macerated corals of this kind are too poorly preserved for positive identification. As unit 2 of GEOLOGIC CORRELATION WITHIN THE GREAT BASIN 17 the Lone Mountain Dolomite is traced southeastward from the Lone Mountain area through the Mahogany Hills to the Fish Creek Range, scattered bodies of dark- gray to black carbonaceous dolomite become increasingly numerous within the lighter, barren blocky phase. Well- preserved silicified fossils in these dark dolomites represent the upper Lone Mountain-Laketown biofacies. Coral beds largely made up of favositids with associated Entelophyllum engelmanni and E. eurekaensis are extensive. - Associated brachiopods are Howellella pauciplicata Waite, H. smithi Waite, Camarotoechia pahranagatensis Waite, and Protathyris hesperalis Waite, together with undescribed species of ?Hyattidina, Hindella, Salopina, and Atrypa. The Confusion Range (Ibex Hills) unit 48 (fig. 7, col. 10) Howellella pauciplicata brachiopod assemblage described in part by Waite (1956) has more recently been elucidated in the Pahranagat Range of southeastern Nevada by Johnson and Reso (1964). Coral faunas in the lower part of the Lone Mountain Dolomite or Lone Mountain unit 1 are little known, as are those in the lower part of the Laketown. Halysites and pycnostylid genera of the East Ridge dolomite block near Romano Ranch, Sulphur Spring Range, are believed to occur in lower beds of this formation. Beds containing an Early Silurian coral zone A assemblage with Palaeocyclus in the Confusion Range, Utah (loc. M1129), occupy an isolated fault block whose position in the Laketown section remains uncertain. RUGOSE CORALS AND GEOLOGIC CORRELATION OF SILURIAN ROCKS WITHIN THE GREAT BASIN Interpretation of overall vertical and evolutionary order among Great Basin Silurian corals depends upon reliability of interarea geologic correlation within the province, as well as upon paleontologic ties with distant reference columns, such as those of eastern North America, Gotland (Sweden), England, and eastern Europe. Within the province, lithologic criteria exclusive of fossils also have value in this connection (fig. 7). Among pertinent factors are lateral continuity of bedded cherts at the system base and wide areal persistence of other distinctive sedi- mentary rock types, such as continuity in particular direc- tions of diagenetic dolomite or the contrasting limestone lithofacies. Contrasting | facies belts distinguished: by pre- dominance of either graptolitic or shelly biofacies have long been recognized in Ordovician and Silurian Systems of the Great Basin. Facies differences of this order greatly complicate or obviate direct paleontologic correlation from basin to basin and justify the multiplication of separate local stratigraphic columns. No better example of such facies variance may be cited than the Ordovician Vinini graptolitic sequences as compared with those of the Pogonip Group, thus far recognized together in fault relationship only. Facies isolation is but slightly less of a deterrent to correlation in the Silurian System of this province. Because of wide acceptance and growing dependability of the remarkable British graptolite sequence, worldwide Silurian stratigraphy and correlation lean heavily upon these fossils. Some belts of Great Basin Silurian exposure have thus far yielded only graptolite evidence, such as the calcareous shales of the Monitor Range stratigraphically below the Helderbergian type Rabbit Hill Limestone. Conversely, much of the Silurian in this province has thus far disclosed no graptolites, as throughout the eastern dolomite belt. By comparison, the intermediate limestone belt with its calcareous shales and platy limestone is graptolite bearing in some places. Graptolites are most abundant in lower horizons, where the shales and laminated limestones readily disclose their graptolitic nature to the collector. Higher in some of the same strati- graphic sections, where limestone bedding is generally thicker and more massive, graptolites are either less evident to the collector or seemingly absent. It is in upper beds of limestone reference sections, as in Coal Canyon, Simpson Park Mountains, in the type Roberts Mountains Limestone area, and in the Mazourka Canyon area, Inyo Mountains, Calif., that the greatest possibilities exist for future discovery of intercalated graptolitic and shelly bio- facies. In the northwestern part of the Great Basin, ap- proaching the Pacific Border graywacke belt (Pacific Border province), graptolitic shales may theoretically be expected to become even more widespread. Geologic correlation by means of a single biologic group may be misleading; use of corals alone in this re- spect would doubtless lead to error. Correlation of seemingly equivalent or identical coral assemblages from place to place is the equating of ecologically comparable coralline biofacies. In the present state of knowledge of these assemblages, it cannot be said with confidence that they do not have greater value as environmental indi- cators than of time equivalence. Little is yet known of the vertical ranges of Silurian coral genera and species. Data from research upon associated fossils are essential in sup- port of rugose coral evidence. Among these, brachiopods are usually common and closely associated in the coral biota. Their supplementary use facilitates greater resolu- tion of correlation problems. Studies of other associated fossil groups are needed; among these are trilobites, ostracodes, conodonts, and calcareous algae. A test of the correlation value of any one of these groups individually is the degree of adjustment required to bring data and the specialist's conclusions based upon these data into reason- able accord with evidence from independent study of the other stratigraphically associated groups. At best, a standard Silurian paleontologic sequence for the Great Basin will always be composite. Thus, for the 18 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN 120° 115° 110° T T T WASHINGTON ] % ) / 4A) MONTANA 45° |- OREGON o pfens Austin (ECarson City \ ha o NFS CALIFORNIA ~ o ~ Fresno e! s 9 } ty Las Vegas ARIZONA » o Z m 1 1 I 0 100 200 MILES 1 2 3 4 5 6 NORTHERN INYO MTS NORTHERN PANAMINT RANGE FUNERAL MTS TOQUIMA RANGE MONITOR RANGE NORTHERN SIMPSON Mazourka Canyon Ubehebe Peak area, Ikes Canyon Dobbin Summit PARK MTS Andy Hills, Whitetop Mtn Coal Canyon Rabbit Hill p Limestone y* oo L— 399 haw Faes yhe , » ¥ Perdido Lost Burro Formation ei Formation -laaap X_ ~s ~ A60 ft f 200 tt Lower Devonian or | Upper Silurian we ET 5 h ”_ cas K Ple c Limestone oquimaphyllum Rhizophyllum p pon ws e and shale me w & Formation E Verticillopora ax®, e?, . Vaughn Gulch 730 ft ? ¢ Toquima- Limestone 720 t s phyllum 1530 ft £ Hidden Valley x & - p b Hidden Valley D olomite Dolomite Stylopleura 1366 tt ind Ryderophyllum Tonkinaria \ Raban'” - s Petrozium LE”??? Verticillopora \ Limestone Dalmanophyllum Verticiltopora B8 Ryderophyllum °" > - - 350 ft i 435 ft ? Dalmanophyllum 510,147?!) e Arachnophyllum A A Arachnophyllum Verticillopore Cvathophylloides Limestone Basal chert _Siluri Palaeocyclus Basal chert Silurian jg: Ely Springs l Gatecliff Formation of Kay Hanson Creek Ordovician y Spri and Crawford (1964) i Dolomite Ely Springs flag! avg? Time: Formation Dolomite stone . of Kay and / _ Crawford (1964) - -- Eureka -en Quartzite Ely Springs gao tt Eursks equivalent Dolomite Eureka Quartzite Quartzite Eureka Quartzite 400 ft FIGURE 7.-Correlation chart of Great Basin GEOLOGIC CORRELATION WITHIN THE GREAT BASIN 19 6 7 8 9 10 11 NORTHERN SIMPSON ROBERTS CREEK MTN LONE MTN FISH CREEK RANGE CONFUSION RANGE GOLD HILL PARK MTS Ibex Hills section Coal Canyon of R.K. Hose Nevada Nevada / Formation Formation ¢ ust evonian _- _ Dolomite Silurian +" Coral beds with o k 3» "al debris of probable i lenee ith oun £709 yllum 2 Tonkinaria Entelophyllum Entelophyllum and Rhizophyll # C i Sr ll: oplafmum Stylopleura Lone Mountain Howellella pauciplicata L _ __ ev _ / Tryplasma Dolomite fauna Verticillopora D Tonkinaria R Lone Mounts) Stylopleura Unit 3 ”Somme“ Sevy Tryplasma 900 ft 1750 ft Dolomite C Tryplasma Sevy Prohexagonaria Dolomite -Rain. Devonian A Silurian Roberts Mountains 7\ Unit 48 Formation p " 2200 ft th, Me Howellella pauciplicata m 9 % fauna s Unit 46 Unit 2 Laketown Verticillopora 1100 ft Dolomite Huronia 1200 ft ; 9 Laketown Lissocoelina Dolomite Dolomite 970 ft 741 ft Unit 1 A Palaeocyclus (M1129) 180 ft | Basal chert Basal chert Lal | Basal chert member Silurian Ordovician Fish Haven Hanson Creek Fish Haven Dolomite Formation Dolomite 250 ft Hanson Creek 425 ft iptamine moon net ane Formaton nm tml. ils, Eureka Quartzite Eures ureka Quartzite 537 ft Eureka Quartzite 11 13 15 GOLD HILL THOMAS RANGE EAST TINTIC MTS RANDOLPH AREA BAYHORSE AREA BORAH PEAK AREA / ? \ / Laketown \ Jefferson / Dolomite Entelophyllum Sevy Dolomite 3000 ft + Lykophyllid coral Dolomite 1200 ft / ‘ / \ Jefferson 5 ? Zelophyllum Dolomite 329 ft Halysites magnitubus / 800 ft+ -L i e \ Pinyon Peak, fhe a I Limestone \ 243 ft 85 ft a beven'gn vor Laketown ’ Victoria Formation #" UC s uskslonn L Reomat Dolomite | 319 j, 278 ft t. Dolomite - 1228 ft L_ \ pevenien ? ' Lykophyllid corals _> 1000 ft Silurian Laketown 2 ? Polyorophe Dolomite 411 ft Bluebell Dolomite 600 1% Entelophyllum 49! ft ? Zelophyllum 1 Pyenactis i ; 135 ft Sllur_ in al [> Silurian Fish Haven Ordovict Tish Haven f Mountain Ordovician Dolomite Dolomite Fish Haven Formation m__. go 285 ft Dolomite 300 ft + Saturday Mountain Entelo- 500 ft a Formation phyllum \ errs 700 ft + Lykophyllid me corals Silurian formations, showing lettered coral zones. 20 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN proposed coral zonation, no single measureable reference section has been found to include all five of the zones in succession. Piecing together of zonal units in partial, over- lapping sections passing from one mountain area to another of structurally deformed beds calls for integration of physical-stratigraphic and paleontologic data, not only from coral and graptolite research but also from investi- gation of all associated organic groups, toward a con- verging pattern of geologic dating evidence. ZIONE A Mazourka - Canyon reference section, - Cali- fornia. thicknesses suggest that the Vaughn Gulch Limestone occupies about the same strati- graphic interval as the Hidden Valley Dolomite to the southeast. The lowest Vaughn Gulch beds contain the zone A solitary rugose coral Dalmanophyllum sp. A, to- gether with a small tryplasmid, a pycnostylid, favositids, Heliolites, and the brachiopod Camarotoechia. The primary zone A indicator Palaeocyclus of the basal Hidden Valley Dolomite was not found in the Vaughn Gulch Limestone. Detailed geologic mapping of the Independence quad- rangle by Ross (1966) demonstrates that northward in Mazourka Canyon the stratigraphic interval normally oc- cupied by the Vaughn Gulch Limestone is in considerable part occupied by calcareous shale, siltstone, and argil- laceous limestone in which Monograptus is a common fossil. Named separately as the Sunday Canyon Formation by Ross (1963), these graptolitic beds may be compared to wholly graptolitic facies equivalents of the Roberts Mountains Formation of the central Great Basin. The Sunday Canyon graptolite beds probably represent horizons above coral zone A. Corals in the uppermost beds of this unit are discussed below under correlatives of Great Basin Silurian coral zone E. Tuscarora Mountains, Nev.-Graptolite beds perhaps slightly younger than coral zone A are known in the Tuscarora Mountains, 75 miles north of Roberts Creek Mountain (Berry and Roen, 1963). The graptolites a few feet above the basal chert corresponding to the basal chert of unit 1 in the type Roberts Mountains Formation were considered to be early Wenlockian by Berry and Roen, re- presenting the British zone of Monograptus riccartonensis. No associated coral or other shelly faunas were reported. Carlin mining district, Nevada.-Strongly deformed Silurian rocks assigned to the Roberts Mountains Formation underlie large areas in the Carlin mine vicinity of the southernmost Tuscarora Mountains. Coral and brachiopod faunas from localities along Maggie Creek for the most part probably represent horizons in the upper part of the formation. A Silurian fossil assemblage of un- known horizon contains Cyathophylloides similar to C. fergusoni of coral zone A. Associated brachiopods are small Coelospira, Fardenia, Ptychopleurella, and small coarse-ribbed _ Conchidium-like - pentamerids. - The brachiopods suggest that this assemblage may be younger than coral zone A. Ruby Mountains, Nev.-Crinoidal dolomitic lime- stone containing the button coral Palaeocyclus occurs at locality M1836, on the north side of the north fork of Mitchell Creek, 3 miles northeast of Mitchell Ranch. As- sociated - are - Halysites, - favositids, Atrypa, - and Camarotoechia-like brachiopods in a fauna probably re- presenting coral zone A. Confusion - Range, - Utah. exposures of Silurian dolomite in this area (loc. M1129) contain a large zone A fauna. Beds in question (R. K. Hose, written commun., 1964) do not form part of a continuous Lake- town Dolomite section but crop out in a minor fault block. Rugose corals of this assemblage are Palaeocyclus cf. P. porpita, Brachyelasma sp., and Tryplasma cf. T. hedstromi. Tabulate corals include favositids, Alveolites, Heliolites, and Halysites. Other fossils are Encrinurus, Hesperorthis, Atrypa, and Atrypina. Ikes Canyon reference section, Nevada.-Platy lime- stone and calcareous shale in the lower part of the Masket Shale of Kay and Crawford (1964, p. 439) are correlative with coral zone A and share with it the colonial rugose coral Arachnophyllum kayi. Other rugose corals in these lower beds are Cyathophylloides - fergusoni - and Neomphyma crawfordi. The primitive cerioid genus Cyathophylloides is more commonly Late Ordovician. Similar Arachnophyllum was reported in the lowermost Gotland Silurian by Lindstrom (1884, p. 7). This genus ranges upward as high as the Brownsport Formation of eastern North America, but in Gotland and the Great Basin it is known only in Early Silurian beds. Roberts Creek | Mountain reference section, Nevada.-The 300-foot interval of unit 1 and the lower- most part of unit 2 in the type Roberts Mountains Formation probably includes the time-stratigraphic equivalent of coral zone A, but it has yielded no Palaeocyclus, Dalmanophyllum, or Arachnophyllum. Other than poorly preserved Monograptus, these beds con- tain pycnostylids, Orthophyllum, favositids, Cladopora, Heliolites, and Halysites. Among the brachiopods are small -like pentamerids, Dicaelosia,Eatonia?, Atrypa, and Merista?. ZONE B Funeral Mountains section, California. zone B faunas have been collected by J. F. McAllister 3 miles south-southwest of Schwaub Peak (Ryan quadrangle), 110 feet above the base of the Hidden Valley Dolomite. Rugose corals are Ryderophyllum, Pycnactis, and Brachyelasma, together with favositids, Heliolites, Hesperorthis, and the cephalopods Huronia and Huroniella. Also present is the large dasycladacean alga Verticillopora. About 300 feet above the base in the same section occurs another fauna GEOLOGIC CORRELATION WITHIN THE GREAT BASIN 21 characterized by Tryplasma, Halysites, Alveolites, Romingerella, and Cladopora. Associated brachiopods in- clude Leptaena, Fardenia, Rhipidium, Atrypa, Atrypina, and Eospirifer (Striispirifer). Lykophyllids, generally to be expected in coral zone B, were not found in this upper horizon. Roberts - Creek Mountain reference section, Nevada. -Fossils of coral zone B are to be expected in the middle and upper beds of unit 2 of the type Roberts Mountains Formation. Possibly because of limestone facies, the zone B indicators Ryderophyllum, Pycnactis, and Petrozium of the Hidden Valley Dolomite have not been found in this section. Rugose corals occurring here are Tryplasma, Palaeophyllum, Diplophyllum, and Microplasma, together with the tabulates Halysites, Heliolites, Cladopora, and Aulopora. Brachiopods abundant in the higher part of unit 2, possibly within the range of coral zone B, are Coelospira, Pytchopleurella, and finely ribbed Conchidium-like pentamerids. Of the last one species superficially re- sembles the Norwegian Conchidium miinsteri Kiaer, as described and figured by St. Joseph (1988, p. 301); this species has been reported in southern Norway Silurian zone 5b and is considered Early Silurian (Llandoverian). ZONE C The distinctive rugose coral fauna of zone C in the Roberts Creek Mountain reference section has not been recognized elsewhere in the Great Basin. In California, that part of the Hidden Valley Dolomite above McAllister's (1952, p. 15) unit 1 and above coral zone B of the type area Hidden Valley has yielded no significant fossil material. Likewise the Vaughn Gulch Limestone in Mazourka Canyon is sparingly fossiliferous within the in- terval where zone C indicators would be expected. In other areas studied, lithologic equivalents of the Roberts Moun- tains Formation, possibly correlative with zone C, belong to the platy graptolitic facies and, therefore, have yielded no Rugosa. LIONE D Mazourka - Canyon - reference section, - Cali- fornia. -Abundant fossils below coral zone E. in the mid- dle of the Vaughn Gulch Limestone are the large dasy- cladacean algae Verticillopora. These are similar to Verticillopora associated with the zone D coral biota in the Roberts Creek Mountain and Ikes Canyon reference sections. Ikes Canyon reference section, Nevada.-Stylopleura, Tonkinaria, and large Verticillopora occupy an interval considerably above the horizon of coral zone A in the Masket Shale of Kay and Crawford (1964, p. 439) at Copper Mountain. Intermediate strata have not yielded the in- dicators of coral zones B and C, but coral zone E is present in higher strata, which Kay and Crawford included in their McMonnigal Limestone. Confusion _- Range, - Utah. -Abundance of - the dasycladacean alga Verticillopora in the upper part of the Laketown Dolomite of the Confusion Range, Utah (fig. 7, col. 10), suggests that the time-stratigraphic interval of coral zone D may be represented. Verticillopora is especially common elsewhere in limestone facies of coral zone D, during which time the genus appears to have peaked. The horizon of prolific Verticillopora lies in unit 46, 330 feet below the top of the Laketown in a strati- graphic section measured by R. K. Hose, of the U.S. Geological Survey, in the Ibex Hills, Confusion Range, Utah (written commun., 1954). In this section the Lake- town Dolomite is 1,203 feet thick and lies between the Fish Haven Dolomite of Late Ordovician age below and the Sevy Dolomite of Early Devonian age above. The distinc- tive Howellella pauciplicata fauna is present in beds 87 feet below the top of the Laketown in unit 48 of the Hose measured section. This fauna also characterizes the higher beds of Lone Mountain Dolomite unit 2 in Nevada and oc- cupies the upper Lone Mountain-Laketown biofacies. Perhaps because of facies differences, the Rugosa of coral zone D do not occur in the Verticillopora beds of the Lake- town or the Lone Mountain. ZIONE E Roberts Creek Mountain reference section, Nev- ada. -Strata above coral zone D in the upper part of unit 3 in the type Roberts Mountains Formation are sparsely fossiliferous dolomite, passing upward into barren dolomite beneath the Nevada Formation. Within this un- differentiated and barren dolomite, coral zone E may well be represented, together with an Early Devonian Rabbit Hill equivalent. Certain zone D corals, such as Stylopleura berthiaumi, are very similar to zone E species, suggesting that zones D and E may overlap; however, as presently known they represent somewhat different biofacies. Ikes Canyon reference section, Nevada. phyllum (Toquimaphyllum) johnsoni, a limestone facies occupant and the most distinctive zone E indicator, is as- sociated with Kyphophyllum on the northwest side of Copper Mountain. The beds appear to lie within the McMonnigal Limestone of Kay and Crawford (1964). Lower horizons in the same section on the southwest con- tain corals of zones D and A. Exposures east of Copper Mountain contain Rhizophyllum and probably also fall in coral zone E. Carlin mine area, Nevada.-Mapping and strati- graphic investigation in progress by the U.S. Geological Survey in this part of northern Eureka County and ad- joining Elko County, Nev., has disclosed strongly de- formed rugose-coral-bearing strata of Late Silurian and Early Devonian ages. These coralline beds are pro- visionally assigned to the Roberts Mountains Formation and to the Rabbit Hill Limestone. At the Bootstrap mine, north of the open-pit Carlin mine, upper beds of the 22 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Roberts Mountains Formation contain large heads of Australophyllum (Toquimaphyllum), n. sp., having smaller and more slender corallites than - 4. (Toquimaphyllum) johnsoni, n. sp., of Silurian coral zone E. Other exposures in the Carlin mine area yield another type of Australophyllum and fragmentary corals classified as Entelophyllum, Palaeophyllum, and Chono- phyllum. The Bootstrap mine Toquimaphyllum is very similar - to - Australophyllum __ (Toquimaphyllum) originalis (Zhmaev) from the Ural Mountains, Russia (Shurygina, 1968, pl. 59, figs. 3a, b). The Ural species originalis is reported to occur with Gotlandian type Silurian corals, this association being interpreted by Russian paleontologists as Early Devonian. Antelope Peak, Elko County, Nev. -Rugose corals from this area north of Wells, collected by B. L. Peterson, include Toquimaphyllum similar to johnsonii of coral zone E and pycnostylids resembling Stylopleura. Mazourka - Canyon - reference section, - Cali- fornia.-Great Basin Silurian coral zone E occupies a 200- foot interval at the top of the middle unit of the Vaughn Gulch Limestone (fig. 3). The interval contains a large and diverse but rather poorly preserved coral biota. The common coral is Toquimaphyllum, which closely re- sembles Australophyllum (Toquimaphyllum) johnsoni; occurring with this are Australophyllum sp., Kypho- phyllum, Chonophyllum-like forms, and Crassilasma? sp. Float material of Rhizophyllum sp. D doubtless came from these beds. Plectatrypa is the only associated brachi0- pod identified. Strata just below coral zone E carry abun- dant large Verticillopora (pl. 16); this dasycladacean alga ranges up into zone E, appearing also in the lowest beds of the upper unit of the Vaughn Gulch Limestone at locality M1093. The upper unit is considered to be Upper Silurian or Lower Devonian. The Verticillopora-rich beds be- neath coral zone E may represent Silurian coral zone D, as these large dasycladaceans appear to have peaked at about that time-stratigraphic interval. Rugose coral indicators of coral zone D were not found in this section. The lowest beds of the Vaughn Gulch upper unit at locality M1093 contain, in addition to Verticillopora, the rugose corals Australophyllum sp. (pl. 12, fig. 5), Kypho- phyllum similar to K. nevadensis (pl. 14), Ryderophyllum sp. (pl. 6, fig. 8), Crassilasma sp. (pl. 6, fig. 9), and Chono- phyllum sp. (pl. 8, fig. 8). The Sunday Canyon Formation (Ross, 1966) exposed north of the Vaughn Gulch area in Mazourka Canyon is largely a graptolitic facies. However, a cerioid rugose coral collected in 1969 by C. H. Stevens in the upper 40 feet of the Sunday Canyon is provisionally assigned to Australo- phyllum; this coral resembles Australophyllum sp. from locality M1093 in the upper Vaughn Gulch unit just above Silurian coral zone E. In both places these higher strata are provisionally classified as Upper Silurian or Lower Devonian (fig. 3). GREAT BASIN RUGOSA AND CORRELATION WITH DISTANT SILURIAN ROCKS Most Great Basin Silurian rugose corals are congeneric with forms known in Europe, Australia, and eastern North - America. Several special researches and monographs upon Silurian Rugosa of Great Britain, Gotland, Czechoslovakia, and Russia facilitate fossil comparison and correlation with reference sections in these distant regions. The Gotland column is an incomparable yardstick for the coral-bearing carbonate Silurian of western Europe and for the rest of the world; it is with Rugosa of this large island that many of the closest paleontologic comparisons are made (fig. 8). Correlation with the standard British Silurian sequence is indirect and places a premium upon graptolite evidence. Neither in the Great Basin nor in Gotland does the known Silurian graptolite succession approach completeness. Hede's (1942) evaluation of the Gotland column in terms of British graptolites provides a circuitous avenue of geologic comparison between the Great Basin and British sequences, through the medium of associated Gotland rugose corals. Noteworthy com- parisons of Great Basin Rugosa with American and Old World Silurian species are dealt with below in accordance with the proposed fivefold zonal scheme. ZIONE A Northwest Canada and Alaska. -Palaeocyclus, reported by Norford (1962, p. 12) from the dolomitic Sandpile Group of northern British Columbia, suggests the presence of an Early Silurian horizon. However, the rather extensive coral assemblages dealt with by Norford appear on the whole to be somewhat younger and are perhaps representative of coral zone B. Palaeocyclus kirby? Meek from Porcupine River, Alaska, was reported by Bassler (1937, p. 190, pl. 30, figs. 7-9) as Devonian; this occurrence has not been confirmed, and an Early Silurian age seems plausible. New York State.-The diagnostic button coral Palaeocyclus of coral zone A suggests correlation with the Clinton Group of New York State and eastern Canada, where species of this coral are fairly common (Bassler, 1937, p. 190). A species of Palaeocyclus from the Michigan Silurian is reported to be somewhat younger. Gotland, Sweden.-Early Silurian (Llandoverian) deposits include the Lower Visby Marl, Upper Visby Marl (fig. 8), and reddish marl stratigraphically beneath the Lower Visby. Oldest of the Gotland rugose corals is a species of Arachnophyllum similar to A. typus (McCoy) which occurs at Visby below the low-water line in the reddish marl underlying the Lower Visby (Lindstrom, 1884, p. 7; Hill, 1958, p. 153). The genus Arachnophyllum is not reported above the reddish marl horizon in Gotland. In North America it continues upward to younger beds of the Niagara Group and the Brownsport Formation CORRELATION WITH DISTANT SILURIAN ROCKS bo C I wo C Pa © > ._} £ 'C 8 § 5 Gotland rugose corals having affinity to Great Basin Silurian , o & 0 w 33 5 A species in coral zones as indicated by symbols and Gotland grapolites Gotlaqd rock < I = m (Hede, 1942) units ® 2 0 & numbers C o i O [s] co | 3 Sundre | | Hamra f | | Burgsvik « | &. [Foquimaphyllum _ | | > fel 5 rectiseptatums ug | Entelophyllum Eke 6 5 .Rh' umm | | fasciculatum* | _ Monograptus Hemse _ |S t le | | nilssoni Klinteberg |- { 1 | § e ‘ | | ‘ | | I Kodonophyllum®5 | I | Cyrtograptys Mulde __ [- | richteri | | | lundgreni | | | | | | 3 6 l 1 | j | Halla # | | Phaulactis | % ig o | cyathophylloides 0 € thonophy/hiin s5 ee - Cyrtograptus ellesi Slite 5 < I flabellata | Pycnactis®2 3 A | mitrata | | | % | Tofta B | | "2 | | | | | f | | w L | hie o I T 1 ra S fs Dalmanophyllum 1 | Kafonopfyllum'5 I | | Hogklint dalmani | read | Phaulact i r SchlotheimophyllumV aZZuasials- | Monqgraptus Upper Visby g $ A patellatum | spiralis B 6 | Aq kel _- 4 N g Palaeocyclus a | ; jus) porpi‘a Arachnophyllum } Lower Visby typus V Schlotheimophyllum is probably related *Entelophylli¢m of upper Lone Mountain- to Mucophyllum of Great Basin Laketown biofacies Silurian coral zone E FIGURE 8.-Gotland stratigraphic units and rugose corals related to Great Basin forms. (Amsden, 1949, p. 104; Stumm, 1964, p. 30) | Petrozium are present in upper beds of the Gazelle Arachnophyllum kayi of Great Basin Silurian coral zone A is similar to 4. typus. Palaeocyclus porpita subsp. mcallisteri of coral zone A rather closely resembles the Lower Visby P. porpita, and Dalmanophyllum sp. A is close to D. dalmani of the Hogklint Group (fig. 8), which is earliest Wenlockian (Hede, in Regnéll and Hede, 1960, p. 55). The Llandoverian Upper Visby Marl contains lykophyllid corals (Phaulactis) and kodonophyllids (Schlotheimophyllum) not present in great Basin coral zone A, the lykophyllids appearing in coral zone B and the kodonophyllids in coral zone E. In terms of the classic Gotland sequence (fig. 8), Great Basin Silurian coral zone A fits in the interval bracketing the Llandoverian reddish marl below the Lower Visby Marl and the early Wenlockian Hogklint Group. IONE B Klamath - Mountains, Calif. -Lykophyllid_ Rugosa assigned to Cyathactis and the kyphophyllid genus Formation, which is considered to be Ludlovian on the basis of brachiopod evidence, supported by similarity of its endophyllid corals to Great Basin zone E Toquimaphyllum. Northwest Canada.-Solitary lykophyllids suggesting zone B Ryderophyllum occur in the Sandpile Group of northern British Columbia (Norford, 1962, pl. XIV, figs. 5-8). Palaeocyclus reported here presumably comes from lower strata representing coral zone A. Gotland, Sweden.-Lykophyllid corals characterizing zone B are common in the Lower and lower Middle Silurian beds of Gotland, where they are represented by the genera Phaulactis and Pycnactis. Zone B lykophyllids are assigned to Ryderophyllum, which, in mature growth stages, closely resembles Phaulactis. In Gotland the lykophyllids appear to have peaked in Wenlockian time. Russia.-A lykophyllid from Podolia assigned by Bulvanker (1952, pl. 2) to Phaulactis cyathophylloides Ryder resembles zone B Ryderophyllum. The Podolian 24 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN species comes from beds reported to range in age from middle Wenlockian to Ludlovian. Shropshire, England. -Petrozium mecallisteri of zone B resembles P. dewari, the type species, described from the Shropshire, England, Early Silurian (Smith, 1930, p. 307). This colonial genus ranges through the Silurian, to judge from the Gazelle occurrence (Klamath Mountains, Calif.), here considered to be Ludlovian. ZONE C New York State.-Entelophylloides (Prohexagonaria) occidentalis is not closely related to Rukhin's type species of Entelophylloides, which is the American Cobleskill Late Silurian Columnmaria inequalis (Hall). It appears doubtful that Great Basin coral zone C is as young as the New York Cobleskill. Gotland, Sweden.-An undescribed Entelophylloides (Prohexagonaria) from the Visby vicinity, figured only in transverse section by Smith and Tremberth (1989, pl. VIII, fig. 1), rather closely resembles zone C occidentalis. The Gotland species, to judge from its recorded geographic occurrence, came from beds somewhere in the interval of the Lower Visby Marl to the Hogklint Group and is, therefore, high Llandoverian to early Wenlockian. Ural Mountains and Siberia.-Cerioid_ Rugosa resembling Entelophylloides (Prohexagonaria) occi- dentalis are known from middle and Upper Silurian beds of the Ural Mountains and Siberia (Sytova, 1952, p. 140, pl. IV; Soshkina, 1955, p. 126, pl. XIII, figs. 2a, 25; Ivanovsky, 1963, p. 86-90, pl. XXII, figs. la, 1b, and pl. XXIV, figs. 2a, 2b). These were initially assigned to Entelophyllum Wedekind, Evenkiella Soshkina, and Tenuiphyllum Soshkina. Species classified as Entelophyllum and Evenkiella are closest to the Great Basin occidentalis. Evenkiella has more of a tendency to develop lonsdaleioid dissepiments, a character not usual with Entelophyllum or - Entelophylloides. _ Entelophyllum _ is normally phaceloid, not cerioid; thus, some of the Russian and Siberian species in question may belong in Rukhin's Entelophylloides. Eastern Australia.-Tryplasma newfarmeri of coral zone C, a smooth, cylindrical, phaceloid tryplasma, is rather close morphologically to Tryplasma lonsdalei Etheridge, as figured by Hill (1940, p. 406, pl. XII, figs. 13a-c) from the Yass-Bowning district. The host rocks are reported to be Wenlockian, possibly including early Ludlovian (Hill, 1940, p. 388-390), and therefore younger than coral zone C. Several Yass-Bowning Rugosa are, in fact, very similar to species in Great Basin coral zone E., here considered to be Ludlovian. IZONE D Kentucky and Tennessee. -Externally - rugate Tryplasma as represented by T. duncanae of coral zone D occurs in the Louisville Limestone of Kentucky and the Brownsport formation of Tennessee. The Louisville species is T. prava (Hall) as figured by Stumm (1964, pl. 6, fig. 8); T. brownsportensis Amsden is the Brownsport representative (Amsden, 1949, pl. XXVII, figs. 7-13). It is probable that both species are older than Great Basin Silurian coral zone D. Gotland, Sweden.-Tryplasma hedstrdomi Wedekind (1927, pl. 29. figs. 1, 2) is externally suggestive of 1. duncanae. The Gotland species comes from the Visby area, probably: from strata ranging in. age from late Llandoverian to early Wenlockian (fig. 8) and therefore considerably older than coral zone D. IONE E Klamath Mountains, Calif. -Rugose corals related to species of Great Basin coral zone F occur in the higher beds of the Gazelle Formation of the northeast Klamath region; other Rugosa in these strata are closer to zone B species. Similar species of the brachiopod Plectatrypa are present in coral zone E and the upper Gazelle beds. Of the Rugosa, Gazelle species of Kodonophyllum, Kyphophyllum, and undescribed endophyllids are allied to zone E species. The Gazelle endophyllids are the analoguelof the new subgenus Toquimaphyllum. Gazelle lykophyllids assigned to Cyathactis resemble zone B Ryderophyllum _ and Gotland Phaulactis. Gazelle Petrozium differs specifically from P. meallisteri of coral zone B. Brachiopod ties between the Gazelle Formation and the Alaskan Silurian favor Ludlovian age and bring these beds more in line with Great Basin Silurian coral zone E. Southeastern Alaska. -A - complex solitary coral collected in Coal Canyon, Simpson Park Mountains, and assigned provisionally to the Russian genus Salatrophyllum Besprozvannikh, 1968 (pl. 12, figs 6-8) is similar to undescribed Salairophyllum in Late Silurian beds of northern Heceta Island and Kuiu Island, Alaska. Collections from locality M1186, Kuiu Island, also include this form in direct association with Late Silurian Conchidium alaskense. Gotland, Sweden.-Three zone E rugose genera are re- presented in Gotland (fig. 8) by similar species. Chono- phyllum simpsoni resembles C. flabellata (Wedekind) of the Slite Group (Wenlockian), Kodonophyllum mulleri resembles K. richter? Wedekind from Lilla Karlsd Island off Gotland, and Rhizophyllum cf. R. enorme Etheridge may be compared to Rhizophyllum of the Hemse Group (Ludlovian). Patellate corals of coral zone E assigned to Mucophyllum oliveri have certain features of Gotland Schlotheimophyllum patellatum (Schlotheim) from the Visby Marl, as figured by Smith (1945, p. 18, pl. $2), but are generically different. Spongophyllum rectiseptatum Dybowski (1878a, p. 479, pl. IV, figs. 3, 3a) is probably Toquimaphyllum. The SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN locality of Dybowski's material suggests a horizon near the Eke Marl of Gotland (fig. 8), and therefore a Ludlovian age. Gotland Rugosa comparable to species of coral zone E. occur within the age range of late Llandoverian for Schlotheimophyllum to early Ludlovian or Mono- graptus nilssoni zone for the Hemse Group Rhizo- phyllum (Hede, 1942, p. 22). Kodonophyllum from Lilla Karlso Island is high Wenlockian or low Ludlovian in age. Czechoslovakia. -Australophyllum __ (Togquima- phyllum) fritschi (Novak, in PoCta, 1902, pl. 102, figs. 6-8) resembles the undescribed. Gazelle Formation endo- phyllids but is probably more closely allied to Australo- phyllum (Toquimaphyllum) johnsonii of Great Basin coral zone E. The Czechoslovakian analogue is con- sidered to be Ludlovian, occurring in strata at Kozel ("'Bande e2"). Prantl (1940, p. 9) termed these beds the "eg" zone. Ural Mountains.-Newly described rugose corals from the Ural Mountains (Shurygina, 1968) resemble species known in the Gotland Silurian, in Silurian rocks of the Cordilleran belt of North America, in southeastern Alaska, in Eastern Australia, and in eastern Europe. Among these Russian corals are species of Toquima- phyllum, several forms of Tryplasma, Neomphyma, Rhizophyllum, _ Spongophylloides, _ Holmophyllum, pycnostylids, and lykophyllids. Others among these Ural corals are possible Kodonophyllum and Kyphophyllum as well as an undescribed cerioid genus occurring in the Silurian Gazelle Formation of the Klamath Mountains, Calif. Strata containing these Russian Silurian-Devonian boundary coral assemblages are in part classified by Shurygina as Early Devonian; in general, all have a decidedly Gotlandian aspect in terms of Rugosa. Australo- phyllum (Toquimaphyllum) giganteum (Shurygina) re- sembles Toquimaphyllum johnsoni of Great Basin Silurian coral zone E. Australophyllum (Toquima- phyllum) originalis (Zhmaev) is strikingly similar to the undescribed Toquimaphyllum earlier mentioned from the higher beds of the Bootstrap mine Silurian section, Carlin mine area. Eastern Australia.-Several rugose corals in Silurian beds of the Yass-Bowning district, as figured by Hill (1940), reveal fairly close morphologic similarities to species of coral zone E. Among these is Australophyllum (Toquimaphyllum) spongophylloides (Foerste), which shows features of Great Basin johnsoni. Also comparable to corals of Great Basin zone E are Yass-Bowning species of - Mucophyllum - and Rhizophyllum. - Tryplasma lonsdale: of these Australian beds resembles a Great Basin Silurian coral zone C Tryplasma. The Yass-Bowning beds were considered by Hill to range in age from high Wenlockian to Ludlovian. 25 CORRELATION OF LONE MOUNTAIN AND LAKETOWN DOLOMITE Silurian dolomite in the Ruby Mountains, Nev.(Ronald Willden and R.W. Kistler, written commun., 1967), is lithologically comparable to Lone Mountain Dolomite. The distinctive button coral Palaeocyclus collected by Willden and Kistler suggests that lower dolomites of this sequence are correlative with Hidden Valley Dolomite coral zone A and may accordingly be equivalent by in- ference to lower beds of the Roberts Mountains Formation in the intermediate limestone belt. Other and probably higher dolomite of the Ruby Mountains contains Entelophyllum- like that of the. upper Lone Mountain-Laketown biofacies in the eastern dolomite belt. As noted elsewhere, isolated dolomite exposures of the Confusion Range, Utah, doubtless pertaining to lower- most Laketown, contain a large coral zone A assemblage. Few of the rugose corals from other Laketown exposures in the eastern Great Basin have been sufficiently studied for generic identification. However, the published lists suggest that some are lykophyllids; others are probably Entelophyllum and the pycnostylids. None suggest the prolific colonial Rugosa of the intermediate limestone belt to the west. Rugose corals provide but meager evidence for cor- relation of the Lone Mountain and Laketown Dolomites with the Silurian of eastern North America. Palaeocyclus of the Confusion Range Laketown and the Ruby Moun- tains suggests a Silurian Clinton equivalence for lower- most Laketown. Entelophyllum of the upper Lone Mountain-Laketown biofacies reveals no intimate or specific relationship to described Entelophyllum of the eastern Louisville Limestone and the Brownsport (Smith, 1933; Amsden, 1949; Stumm, 1964), all of which are geologically older. Gotland Entelophyllum ranges upward from Visby Marl (Wedekind, 1927) to the Eke Marl and Hemse Group. Upper Lone Mountain-Laketown Entelophyllum is closer to Gotland species from the higher Wenlockian and to those of the Eke and Hemse (Ludlovian). Among these, Entelophyllum articulatum (Wahlenberg) resembles the Lone Mountain E. eurekaensis, and E. fasciculatum Wedekind is similar to E. engelmanni of the Lone Mountain Dolomite. Ludlovian age of the upper Lone Mountain-Laketown biofacies containing Entelophyllum, as concluded on the basis of the Howellella pauciplicata fauna, suggests that this higher Silurian zone may fall within the interval of combined coral zones D and E. In possible support of this conclusion, the dasycladacean alga Verticillopora seems to have peaked in about the interval of coral zone D and oc- curs abundantly in unit 46 beneath the Howellella pauciplicata beds of Confusion Range unit 48. (See fig. 7; tol 10;) 26 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN AGE CONCLUSIONS BASED ON SILURIAN RUGOSA Provisional age determinations are based largely upon rugose coral comparison with European and Australian faunas, especially those in formations of the Gotland sec- tion. Of supplementary value are coral and brachiopod comparisons with Klamath Mountains and Alaskan Silurian, as well as with Silurian of eastern North America. Base and top of the Great Basin Silurian are fixed paleontologically with some assurance by coral faunas of zones A and E, of which zone A is the firmer in terms of European correlation (fig. 9). Zone A is late Llandoverian; zone E is considered to be late Ludlovian. Intermediate zones B and C are Wenlockian; zone D is provisionally re- garded as early Ludlovian. Supporting evidence is needed from detailed study of associated brachiopods, as well as from graptolites collected in established sections where graptolitic and shelly facies are both represented. Stratigraphic ranges of Silurian rugose coral genera are little known. A few, such as Palaeocyclus and Dalmano- phyllum, seem restricted to the lower part of the system, but most carry through the middle Silurian Wenlockian to the Late Silurian. Peaks or regional bursts within certain generic lineages and confined to given stages may have age significance, as among the lykophyllids. In Gotland the Lykophyllidae peak, or attained an evolutionary acme, within early and middle Wenlockian time. Gotland Rhizophyllum reveals but a single burst-that of the Ludlovian Eke and Hemse (fig. 8). The subgenus Toquimaphyllum and related endo- phyllids have thus far been recognized only in Ludlovian and Early Devonian (Helderbergian) rocks. Myco- phyllidae range upward from the late Llandoverian (Upper Visby) to Great Basin coral zone E (Ludlovian). The Upper Visby Schlotheimophyllum is generically dis- tinct from the higher Wenlockian and Ludlovian Mucophyllum of Australia, the Klamath Mountains, and the Great Basin. Long-ranging as a big genus, Entelophyllum will eventually lend itself to taxonomic subdivision. In Gotland (fig. 8), Entelophyllum is common and diverse in the Eke Marl (Ludlovian), as it is in the Great Basin upper Lone Mountain-Laketown biofacies, also considered to be Ludlovian. Eastern representatives of this group in the Louisville and Brownsport are older. Great Basin Silurian coral zone A. -Late Llandoverian age of coral zone A harmonizes with the Gotland occur- rence of Palaeocyclus porpite and pre-Lower Visby Arachnophyllum (fig. 9). Great Basin Dalmanophyllum sp. A is related to Hogklint Dalmanophyllum dalmani, an early Wenlockian coral in Gotland. Great Basin Silurian coral zone B.-Wenlockian age of coral zone B is supported by fairly conclusive superposi- tion above the interval of coral zone A and by the presence of the lykophyllids Ryderophyllum and Pycnactis. In Gotland this family peaks in the Wenlockian. Petrozium of coral zone B resembles the high Llandoverian P. dewar; of Shropshire, England, but is also similar to Petrozium of the Ludlovian beds in the upper part of the Gazelle Formation in the Klamath Mountains. Great Basin Silurian coral zone C.-Probable Wen- lockian age of coral zone C is neither strongly supported nor controverted by two rugose corals, Tryplasma new- farmeri and Entelophylloides (Prohexagonaria) occiden- talis, or by its stratigraphic position in the Roberts Creek Mountain reference section (fig. 4) below coral zone D. Tryplasma new farmeri is similar to T. lonsdalei of the late Wenlockian and Ludlovian Yass-Bowning beds of Australia. The Entelophylloides resembles a species from Visby, Gotland, which is probably no younger than Wenlockian. Study of the abundant brachiopod fauna of Roberts Mountains unit 2 just beneath coral zone C is expected to shed light on the age of these beds. Conchidium-like pen- tamerids seemingly differ from all known Late Silurian Conchidium of the Pacific Border province in the Klamath Mountains and in southeastern Alaska. Great Basin Silurian coral zone D.-This coral zone is provisionally regarded as early Ludlovian, pending elucidation of the stratigraphic relationship of coral zone D to Ludlovian coral zone E within the Roberts Creek Mountain reference section. The two zones share the dis- tinctive pycnostylid genus Stylopleura and may overlap in the time-stratigraphic sense. Occurrence of Verticilloporae in type coral zone D suggests that it may predate zone E.; this dasycladacean is especially. abundant immediately be- low coral zone E of the Mazourka Canyon reference sec- tion (fig. 3). The rugate Tryplasma duncanae of coral zone D suggests a somewhat greater age, as it resembles . probable Wenlockian T. prava of the Louisville Lime- stone (Stumm, 1964, pl. 6, fig. 8) and the Gotland T. hedstromi from strata that are probably also Wenlockian (Wedekind. 1927. pl: 29; figs. 1, 2). Great Basin Silurian coral zone E.-Coral zone E of late Ludlovian age includes the uppermost Silurian beds of the Great Basin within the intermediate limestone belt. Over- lying beds in the Coal Canyon reference section carry the Helderbergian (Early Devonian) Rabbit Hill fauna. Endo- phyllid corals of the subgenus Toquimaphyllum are characteristic and related to an undescribed member of this family in Ludlovian upper members of the Klamath Mountains Gazelle Formation. Australophyllum (To- quimaphyllum) johnsoni of zone E is comparable to Spongophyllum rectiseptatum Dybowski of the Gotland Ludlovian Eke Marl, as well as to species of Toquima- phyllum in the Late Silurian of Czechoslovakia. Australian species in the Yass-Bowning beds are reported to be of late Wenlockian and Ludlovian age. COMPARISON OF SILURIAN CORALLINE ROCKS 27 £ w & 3 © $ $2 m ' I ) i. O 5 o 32% | | | | | | | | I hyll E I Kod hyll Toquimaphyllum : | ped Pi IT Kyphophyllum Chonophyllum o | Mucophyllum 2 a 3 | I I I I | D Stylopleura I Tonkinaria : | | I | T > | .G f 3 | o C Prohexagonaria f | _ Denayphyllum | | o | | | $ t E | I S , i | 1 | | B Palaeophyllum Petrozium Ryderophyllum | Tryplasma | Pycnactis | | | i 1 1 | | i I g A Brachyelasma ‘ Cyathophylloides |__ Palaeocyclus Neomphyma Arachnophyllum 3 Dalmanophyllum c ( I $ |/ k I | C | € I 3 8 5 f | | O I | l I FIGURE 9.-Stratigraphic occurrence of characteristic Great Basin Silurian rugose coral genera. The Ludlovian burst of Rhizophyllum in the Hemse and Eke horizons of Gotland (fig. 8) is more or less paral- leled by Rhizophyllum of Silurian coral zone E. However, the stratigraphic range of this genus extends at least from the Brownsport of eastern North America to the Early Devonian Konieprus of eastern Europe. In Australia and in Alaska, also, this coral is reported to have survived into the Devonian Period. COMPARISON OF SILURIAN CORALLINE ROCKS IN THE GREAT BASIN WITH THOSE OF OTHER REGIONS Morphologic and taxonomic comparisons of Great Basin Silurian corals with corals of the classic Silurian re- gions provide a basis for geologic correlation; at the same time, these studies invite comparative treatment of de- positional and environmental conditions under which the coral-bearing strata accumulated. In this connection, two types of marine environment, broadly speaking, are considered: the environment of tectonically active geo- synclinal belts, represented by the graywacke belt of the Pacific Border province, and the shelf environment, re- presented by the Niagara Series of the Great Lakes and the Gotland Silurian. In the Pacific Border graywacke belt, great volumes of siliceous conglomerate, graywacke, bedded chert, and sub- marine volcanics manifest recurrent crustal movement and vulcanism. Depositional environments such as this might be expected to inhibit limestone accumulation and therefore to provide few benthonic sites favorable for ex- tensive coral growth. Coralline rocks of the Klamath Mountains, Calif., and of southeastern Alaska fall within this province. Limestones of these regions are mostly lenses within the "dirty" siliceous clastics. Surprisingly 28 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN enough, however, many of these circumscribed carbonate bodies are fairly pure, and many are coral bearing. Diagenetic dolomitization processes were not in operation here. Rugose corals of colonial growth habit are more abundant in the Klamath Mountains than in south- eastern Alaska, where Silurian coralline life in general ap- pears to have been somewhat less diverse and prolific. So far as known, the unstable tectonic-volcanic conditions of this belt did not foster environments required for wide- spread patch reef or biohermal growth like those of shelf seas. Silurian corals of the Pacific Border graywacke belt and the rocks in which they occur are treated in a separate report (Merriam, 1972). Coral faunas of the Great Basin Silurian appear to be less closely related to those of the Middle Silurian Niagara shelf seas than to those of either the Pacific Border pro- vince or the Gotland Silurian. However, the lack of well- preserved Niagara coral comparative material makes pos- sible only the vaguest of generalizations in this regard. Taxonomically and environmentally, the western faunas appear to differ appreciably. Unlike the Great Basin Silurian seas, shallow Niagara carbonate seas of the Great Lakes area | were.. optimal - for proliferation . of bioherm-patch-reef complexes characterized by un- stratified, altered core rock, inclined flank beds, and partial dolomitization, especially of the core rock (Lowenstam, 1948, 1950). For purposes of this investigation, the coral faunas of Gotland, Sweden, have provided a most valuable standard of morphologic and taxonomic comparison. In terms of deposition and environment, the Gotland column is, likewise, the best yardstick for the world Silurian marine carbonate rocks. In Gotland, the Silurian System is about 1,600 feet thick (Regnéll and Hede, 1960, p. 46), a thickness comparing favorably with the Great Basin Silurian average thickness. Both sequences have the carbonate depositional character- istics of shelf seas, and both have a comparatively small thickness for the Silurian System in a world sense. For example, the geosynclinal Silurian of southeastern Alaska is about 20,000 feet thick, or 12 times the thickness of the system in carbonate stable-shelf columns. Conceivably, the greater part of Silurian time is recorded by sediments and faunas of the Gotland reference column, which com- prises 13 primary map units that are defined on the basis of physical rock differences and supported by paleontologi- cal evidence. Whereas the Gotland strata and those of the Great Basin Silurian are predominantly carbonate, much argillaceous matter was pervasively admixed during the course of sedimentation in Gotland. The argillaceous de- bris, evidently of terrigenous derivation, occurs through- out the section as argillaceous limestone, marlstone, clay- stone, and shale. Associated with these sediments in Gotland are biohermal limestone, sandstone, oolitic lime- stone, and minor bentonitic deposits. Unlike Great Basin Silurian and unlike the Great Lakes Niagaran, the Gotland Silurian includes very little dolomite. Major lime contributors in Gotland were the crinoids, stromato- poroids, calcareous algae, and corals. Especially distinctive of the Gotland Silurian are in- numerable bioherms in which the corals are associated with other lime contributors. These depositional features are found in some 10 of the 13 Gotland units. Typically, the Gotland bioherms have unstratified limestone cores of inverted cone shape which intertongue laterally with reef detritus (Hadding, 1941, 1950; Jux, 1957; Regnéll and Hede, 1960). Unlike the Niagara bioherms, those of Gotland do not ordinarily have core-rock dolomitization. Greenish-gray or red argillaceous limestones occur with some Gotland bioherms. Although the Gotland Silurian is mainly of shelf-sea character, these lithologically diverse strata were re- peatedly influenced during accumulation by landward crustal disturbances. Hinterland deformation acting upon the terrigenous debris source areas is manifested in the complex record of Gotland marine-sediment discontinui- ties, both vertical and lateral. Bioherm growth on the shallow sea floor was markedly influenced by frequent marine current changes, together with landward or sea- ward shift of the shore zone as a result of deformation. DEPOSITIONAL FEATURES OF GREAT BASIN SIL CORALLINE ROCKS IN RELATION TO THE REEF PROBLEM Field studies of Great Basin Silurian coral-bearing strata have thus far failed to disclose complex bedding structures like the classic bioherms or patch reefs of the Niagara and Gotland sequences. Coral-rich limestones of the intermediate limestone belt are usually medium- coarse-grained jumbled bioclastics in which bedding is fairly even and crinoidal debris predominates. All fossils in such facies are obviously transported, the corals com- monly showing little evidence of wear and having scat- tered, random distribution. Such deposits appear to have formed as banklike accumulations to which the fossils had been carried only short distances from their growth sites. Generally lacking in these limestones are in situ organic- growth depositional structures which possessed initial bottom relief. Unstratified core rock and inclined flank beds like those of the Niagara and Gotland patch reefs have not thus far been recognized in the Great Basin Silurian strata. In the Great Basin Silurian, few exposures have been ob- served which reveal corals entombed in their original growth positions, but among these exposures are certain Entelophyllum beds in Lone Mountain Dolomite of the Mahogany Hills and the Fish Creek Range. There, large, laterally extended colonies of a rather open colonial form occupy fairly even beds and seemingly existed in thin, dispersed coral fields. None of these in situ growths were CLASSIFICATION OF GREAT BASIN SILURIAN RUGOSA 29 observed to have the wave-resistant mound, or dome con- figuration, which might have developed as a result of continued upward accretion of corals, algae, and other or- ganisms, aided by sediment-binding agents. Theoretically, the Silurian shelf seas of the Great Basin in both limestone and dolomite belts would be expected to favor bioherm or patch-reef complexes in ecologically suitable places. The coral-rich bioclastics earlier dis- cussed are perhaps interreef facies; the Entelophyllum fields may be reef-marginal or lagoonal. Another sug- gestion of reef proximity is the lenticular occurrence of contemporaneous depositional limestone breccias con- taining abundant corals. These have been described in the topmost Roberts Mountains limestone of the Simpson Park Range, Nev. (Winterer and Murphy, 1960, p. 126). At Coal Canyon the limestone clasts and matrix of these de- positional breccias have yielded much of the Silurian coral study material from that vicinity. In theory, coarse de- positional breccias of this kind might form as a product of wave action along a reef front. Other reefal features, such as inclined flank beds and unstratified core rock, were not observed in association. Similar coarse coral-rich lime- stone breccia-conglomerates are known also in the Kla- math Mountains Silurian within the tectonically active Pacific Border graywacke belt; here again there is no further supporting evidence of reef origin (Merriam, 1972). In comparison with the great stratigraphic and facies complexities of the shelf sea Gotland Silurian with its numerous patch reefs, the Great Basin Silurian of the eastern dolomite belt is on the whole far more uniform, as it has fewer abrupt lithofacies discontinuities. Tectonical- ly, the marine environmental conditions appear to have been more stable in the Great Basin dolomite belt than in the Gotland nondolomitic, commonly very muddy seas. From these environmental assumptions, one can perhaps speculate that the more uniform, dolomitic deposition in the eastern dolomite belt served in some manner to arrest the development of reefal structures. Fairly stable tectonic conditions, again without proven marine reefal manifestations, prevailed also to the west within the Great Basin intermediate limestone belt. De- creasingly stable tectonic conditions probably prevailed in the westernmost part of the limestone belt as the hypothe- tical transition to the Pacific Border graywacke belt of active Silurian tectonism is approached. Hence, marine environments more like those of Gotland may con- ceivably have existed in buried and unexplored terrane in the northwestern part of the Great Basin province. DASYCLADACEAN ALGAE IN GREAT BASIN SIL CORALLINE DEPOSITS Plate 16, figures 5-17 Calcareous algae of the family Dasycladaceae were among the major limestone builders and played a 504-634 O - 73 - 3 significant role in the economy of Great Basin Silurian seas. Dasycladaceae are represented here by Verticillopora Rezak, the conical to cylindrical thalli of which were long confused with sponges or with large crinoid stalks, either of which they may closely resemble. In 1954, P. E. Cloud called the writer's attention to plant affiliation of these fos- sils, following which the collections were intensively studied by Rezak (1959). Intimate ecologic association of Great Basin Silurian Rugosa with dasycladaceans calls for a brief reference to these plants. As in the Gotland Silurian (Rothpletz, 1908, 1913), cal- careous algae are known to have contributed much lime in the Great Basin and the Pacific Border seaways. Johnson and Konishi (1959) and Rezak (1959) showed that Dasycladaceae, Solenoporaceae, and other algal families were active in the Klamath Mountains Silurian; however, the large Verticillopora was not recognized in that region. The Great Basin Verticillopora ranges upward from coral zone B through coral zone E. It is, however, in about the interval of coral zone D that this fossil is most abundant. Verticillopora annulata develops to large size and in a variety of cylindrical, conical, and irregular turbinate shapes. In some beds of the Vaughn Gulch Limestone below coral zone E., this alga outnumbers the rugose corals. Similar large thalli occur with Rugosa in zone D of the Ikes Canyon reference section. In the Roberts Creek Mountain reference section, Verticillopora of coral zone D is smaller and more like that of unit 46 in the Laketown of the Confusion Range. (See fig. 7, col. 10.) Verticillopora of coral zone B is narrowly cylindrical, strongly suggestive of a crinoid stalk, and may represent a distinct species. CLASSIFICATION OF GREAT BASIN SILURIAN RUGOSA Great Basin Silurian rugose corals here described are classified in 13 families. The usage and content of several families depart from Hill's 1956 classification, the most comprehensive and authoritative published thus far. De- partures from Hill's scheme include the elevation of cer- tain subfamilies to independent family status, the restora- tion of the family Pycnostylidae, and the shift of certain genera from one family to another believed to be more ap- propriate. Of three new genera proposed, Denayphyllum is not assigned to a family. Family Streptelasmatidae Nicholson, ' 1889 (as Streptelasmidae). Genus Rhegmaphyllum Wedekind, 1927 Rhegmaphyllum sp. h Genus Brachyelasma Lang, Smith, and Thomas, 1940 Brachyelasma sp. B Genus Dalmanophyllum Lang and Smith, 1939 Dalmanophyllum sp. A Family Stauriidae Edwards and Haime, 1850 Genus Cyathophylloides Dybowski, 1873 Cyathophylloides fergusoni, n. sp. 'In Nicholson and Lydekker (1889). 30 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Family Stauriidae Edwards and Haime, 1850-Con. Genus Palaeophyllum Billings, 1858 Palaeophyllum sp. b Palaeophyllum? sp. c Family Pycnostylidae Stumm, 1953 Genus Stylopleura, n. gen. Stylopleura berthiaumi, n. sp. Stylopleura nevadensis, n. sp. Family Tryplasmatidae Etheridge, 1907 Genus Tryplasma Lonsdale, 1845 Group 1: Solitary-rugate Tryplasma Tryplasma duncanae, n. sp. Group 2: Fasciculate-cylindrical Tryplasma Tryplasma newfarmeri, n. sp. Tryplasma sp. R Genus Rhabdocyclus Lang and Smith, 1939 Rhabdocyclus sp. B Rhabdocyclus sp. d Rhabdocyclus sp. K Genus Palaeocyclus Edwards and Haime, 1849 Palaeocyclus porpita subsp. n. subsp. Genus Zelophyllum Wedekind, 1927 Family Kodonophyllidae Wedekind, 1927 Subfamily Kodonophyllinae, new subfamily Genus Kodonophyllum Wedekind, 1927 Kodonophyllum mulleri, n. sp. Subfamily Mycophyllinae, new subfamily Genus Mucophyllum Etheridge, 1894 Mucophyllum oliver, n. sp. Family Arachnophyllidae Dybowski, 1873 Genus Arachnophyllum Dana, 1846 Arachnophyllum kayi, n. sp. Family Lykophyllidae Wedekind, 1927 Genus Pycnactis Ryder, 1926 Pycnactis sp. k Genus Cyathactis Soshkina, 1955 Cyathactis? sp. Genus Ryderophyllum Tcherepnina, 1965 Ryderophyllum ubehebensis, n. sp. Family Cystiphyllidae Edwards and Haime, 1850 Genus Microplasma Dybowski, 1873a Microplasma? sp. R Family Goniophyllidae Dybowski, 1873a Genus Rhizophyllum Lindstrom, 1866 Rhizophyllum sp. D, Oliver Family Kyphophyllidae Wedekind, 1927 Genus Kyphophyllum Wedekind, 1927 Kyphophyllum nevadensis, n. sp. Genus Petrozium Smith, 1930 Petrozium meallisteri, n. sp. Genus Entelophyllum Wedekind, 1927 Entelophyllum eurekaensis, n. sp. Entelophyllum engelmanni, n. sp. Genus Entelophylloides Rukhin, 1938 (as subgenus) Subgenus Prohkexagonaria, n. subgen. Entelophylloides (Prohexagonaria) occidentalis, n. sp. Genus Neomphyma Soshkina, 1937 Neomphyma crawfordi, n. sp. Genus Tonkinaria, n. gen. Tonkinaria simpsoni, n. sp. Family Chonophyllidae Holmes, 1887 Genus Chonophyllum Edwards and Haime, 1850 Chonophyllum simpsoni, n. sp. Family Endophyllidae Torley, 1933 Genus Australophyllum Stumm, 1949 Subgenus Toquimaphyllum, n. subgen. Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. Family Acervulariidae Lecompte, 1952 Genus Diplophyllum Hall 1852 Diplophyllum? sp. m No family assignment Genus Salairophyllum Bresprozvannikh, 1968 Salairophyllum? sp. Genus Denayphyllum, n. gen. Denayphyllum denayensis, n. gen., n. sp. SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY All 35 rugose coral species treated in this report were previously undescribed. Five are classified in the new genera Stylopleura, Tonkinaria, and Denayphyllum; two are assigned to the new subgenera Entelophylloides (Prohexagonaria) and Australophyllum _ (Toquima- phyllum). Twenty of the new species are given formal names, being represented in our collections by well- preserved material considered appropriate for complete diagnosis. Fifteen species, mostly solitary Rugosa, are designated provisionally and informally by letter; whereas these lettered taxa have prime stratigraphic value, they are represented by rather poorly preserved, mostly incom- plete specimens judged too few and inadequate to warrant formal species naming at present. In general, the strati- graphically more important unnamed species are assigned capital letters. Regretfully, with all of the studied species, the number of sectioned coralla is insufficient for quantitative variation techniques, which by modern standards is a part of any species characterization. The Great Basin Silurian coral zone is indicated under occurrence of most species. Locality numbers, such as M1097, are recorded in the U.S. Geological Survey Menlo Park Paleozoic fossil locality catalogue; also, a register of these locality numbers accompanies this report. Descriptive terminology used in this report is largely that proposed by Hill in 1985 and 1956. Family STREPTELASMATIDAE Nicholson, 1889 * (as STREPTELASMIDAE) Reference genus and species. corni- culum Hall. Ordovician, New York. Mostly solitary rugose corals lacking dissepiments, and with a septal stereozone; tabulae and tabellae usually but not always arched, and involved with septal ends as an axial structure in some species. In genera with a wide stereozone, tabulae may be obscure. This diverse and long-ranging family is probably an- cestral to a large number of the post-Ordovician rugose *In Nicholson and Lydekker (1889). SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY 31 corals and will probably eventually lend itself to sub- family _ taxonomic - subdivision. - Rhegmaphyllum, Brachyelasma, and Dalmanophyllum are the Great Basin Silurian Rugosa here classified. Genus RHEGMAPHYLLUM Wedekind, 1927 1831. Turbinolia turbinata Hisinger (in part), p. 128. 1868. Zaphrentis. conulus p. 428; pl. 6, fig. 8. 1927. Rhegmaphyllum Wedekind, p. 14, pl. 24, figs. 6-8. 1940. - Rhegmatophyllum Lang, Smith, and Thomas, p. 114. 1956. Rhegmaphyllum Wedekind. Hill, p. F269, fig. 182,9b, Oc. Type - species. -Rhegmaphyllum _ turbinatum (Hisinger); by subsequent designation (Soshkina, 1937, p. 85; see also Lang, Smith, and Thomas, 1940, p. 114). Silurian, Wenlockian, Slite group, Gotland, Sweden. Diagnosis.-Small, solitary ceratoid-trochoid rugose corals with long, smooth major septa, some of which ex- tend to axis; minor septa less than half the length of major septa. Septal stereozone narrow. Tabulae arched, some complete; may be weakly developed. Exterior nearly smooth; septal grooves weak or absent. Remarks.-These small and rather simple solitary streptelasmid corals are smaller than Streptelasma and have a narrower stereozone and a more discrete fossula. Orthophyllum of PoCta (1902, pl. 112, figs. 5-7) has few or no minor septa and lacks a well-defined fossula. (See also Smith, 1990, p. 504.) fig. 4.) In the Great Basin province, corals of this kind occur in the lower part of the Silurian. Rhegmaphyllum sp. h Plate 1, figures 7, 8 Small silicified corals assigned to Rhegmaphyllum sp h occur in the lower part of the Hidden Valley Dolomite of southwest Great Basin. Only the exterior is known be- cause the material is inadequate for thin-section pre- paration. Figured corallum with 26 smooth major septa in a deep conical calice, at the bottom of which most major septa meet the axis. Cardinal septum abbreviated in its fossula. Outer surface is almost smooth, with faint traces of longitudinal grooves. Occurrence.-In lower beds of the Hidden Valley Dolomite, Early Silurian, coral zone A northern Panamint Range, where it is associated with Dalmanophyllum, Tryplasma, and Palaeocyclus. Whitetop Mountain, northern Panamint Range, locality M1096. Study material consists of three silicified coralla. Genus BRACHYELASMA Lang, Sn. 1940 1927. Dybowskia Wedekind, p. 18, pl. 1, figs. 10, 11 [not Dall, 1876]. 1940. Brachyelasma Lang, Smith, and Thomas, p. 28. 1956. Brachyelasma. Hill, p. F268, fig. 182,5a, 5b. Type species. -Dybowskia prima Wedekind; by original designation (Lang, Smith, and Thomas, 1940, p. 28). Stavnestangen, Tyrifjord, Norway; in strata of either Late Ordovician or Early Silurian age. Diagnosis.-Trochoid-ceratoid solitary rugose corals lacking dissepiments and having subhorizontal, straight, or slightly arched tabulae, some of which are complete. Tabulae bent downward as they approach the wall. Major septa not meeting the axis, though commonly extending more than half that distance. Minor septa short. Septal stereozone narrow. A fossula recognizable in some species. Remarks.-Brachyelasma shares some of the char- acteristics of Devonian siphonophrentids, especially the subgenus Breviphrentis which differs in possessing an elongate subcylindrical corallum and has amplexoid septa together with a wider stereozone (Merriam, 1973c). Siphonophrentis (Breviphrentis) commonly undergoes repeated rejuvenescence to give the corallum a narrow seg- mented appearance. , Brachyelasma occurs in rocks of Late Ordovician, Early Silurian, and early Middle Silurian age. The type species, B. prima, is reported by Lang, Smith, and Thomas (1940, p. 28) to be Llandoverian, although Hill (1956, p. F268) implied a Late Ordovician age. In the Toquima Range of the Great Basin this genus has been found in the lower part of the Gatecliff Formation of Kay and Crawford (1964, p. 437), which may be pre-Richmondian; Brachyelasma is found also in the Ely Springs Dolomite of Richmondian age, and in Silurian coral zones A and B. Brachyelasma sp. B Plate 1, figures 9-11; plate 16, figures 1, 2 Silicified corals upon which this description is based were collected from the lower part of the Hidden Valley Dolomite in the northern Panamint Range and in the Funeral Mountains, Calif. About 32 major septa, thickened peripherally, tapering axially, and withdrawn from the axis; minor septa short. Septal stereozone very narrow. Tabulae complete, close spaced, and straight except for peripheral downward bend. No suggestion of a fossula, in transverse thin sec- tions. One weathered specimen (pl. 16, fig. 2) shows a dis- crete fossular down-bend of the calice tabula in the position of a primary septum. Occurrence.-Early Middle Silurian, coral zone B; lower part of the Hidden Valley Dolomite. Northern Panamint Range: Ubehebe Peak area, locality M1094; Andy Hills, locality M1095. Funeral Mountains, Pyramid Peak area, localities M1097, M1127. A somewhat different Brachyelasma occurs at locality M1098 in the Schwaub Peak area, Funeral Mountains (pl. 1, figs. 5, 6). Study material consists of two coralla (M1094), one corallum (M1095), one corallum (M1097), and one corallum (M1127). 32 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN In »*#ihe>> Confusion: Range,. Uiah (loc.. MH129), Brachyelasma of this same general type is associated with Palaeocyclus and a large fauna indicative of Silurian coral zone A. Brachyelasma like the sp. B occurs elsewhere in beds of probable Late Ordovician age, such as the Gate- cliff Formation of Kay and Crawford (1964) in the Toquima Range and beds in the Tuscarora Mountains of northern Eureka County, Nev., where this coral genus is associated with Catenipora, - Palaeofavosites, - and Hesperorthis. Genus DALMANOPHYLLUM Lang and Smith, 1939 1933. - Tyria Scheffen, p. 33, pl. V, figs. 2, 3. 1939. Dalmanophyllum Lang and Smith, p. 153. 1940. Dalmanophyllum. Lang, Smith, and Thomas, p. 49. 1956. Dalmanophyllum. Hill, p. F269, {fig. 182.6a-6c. 1961. Dalmanophyllum Lang and Smith. Minato, p. 81-86, text figs. 20-23; pl. XL, pl. XIX, figs. 2-5. Type species. dalmani Edwards and Haime, 1851; by original designation (Lang and Smith, 1999; "p: ~ 158). Silurian. Gtoup, early Wenlockian, Gotland, Sweden. Diagnosis.-Small solitary rugose corals of trochoid shape with solid bladelike axial structure projecting up- ward in bell-shaped calice; transverse outline of calice rim broadly ovoidal and nonangulate. Fossula in line with median plane of axial structure. Major septa project axial- ly to columella in early adult and younger growth stages. Minor septa short; major septa dilated. Septal stereozone narrow. Tabulae largely suppressed by septal thickening. Dissepiments absent. Remarks.-Dinophyllum _ differs from Dalmano- phyllum in having a loose and open axial structure rather than a solid columella; its major septa are usually less dilated and are twisted toward the axis. Dinophyllum commonly does not develop well-defined short minor septa and is more often ceratoid than trochoid. The Late Ordovician Bighornia (Duncan, 1957) re- sembles Dalmanophyllum, but it normally is flattened apically, and the mature transverse section is commonly angulate. Bighornia may show even more dilated major septa than Dalmanophyllum, and minor septa are more weakly developed. Dalmanophyllum sp. A Plate 1, figures 1-3 Dalmanophyllum sp. A is known only from exteriors; available material is insufficient for sectioning. External- ly, this species closely resembles D. dalmani (Edwards and Haime), as figured by them (1851, pl. 1, fig. 6); a copy of one holotype figure of dalmani is here reproduced for comparison (pl. 1, fig. 4). Epitheca with faint longitudinal striations, but no pro- nounced septal grooves; moderate rugae developed. Major septa in mature calice about 36; septa straight and smooth peripherally, becoming periaxially wavy where they join the laterally compressed columella. Solid columella pro- jecting upward 3 millimeters in calice and elongate-ovoid in cross section, with long axis in cardinal-counter plane. Short septum in fossula probably the cardinal septum; fossula situated on convex side of corallum. Occurrence.-KEarly Silurian, coral zone A. Basal beds of Hidden Valley Dolomite, Whitetop Mountain, northern Panamint Range; locality M1096. Basal part of Vaughn Gulch Limestone, Mazourka Canyon, northern Inyo Mountains, locality M1091. Study material consists of the two complete silicified figured specimens and fragments of coralla from Whitetop Mountain (loc. M1096). Comparable columellate solitary corals assignable either to Dalmanophyllum or to Dinophyllum occur in the lower part of the Silurian section, Gazelle area, north- eastern Klamath Mountains, Calif., and in the Mont- gomery Limestone near Taylorsville, Calif. Family STAURIIDAE Edwards and Haime, 1850 Reference genus and species.-Stauria astreiformis Ed- wards and Haime. Silurian, Gotland, Sweden. Fasciculate and cerioid rugose corals having slender corallites mostly without dissepiments; tabulae straight or arched, and long lamellar major septa commonly extend to the axis. In some lineages of this family, dissepiments in a single column or sporadically in a broken column. Two of the species here described are placed in genera classified as Stauriidae; these are Cyathophylloides and Palaeophyllum. Genus CYATHOPHYLLOIDES Dybowski, 1873 1851. Columnaria gothlandica Edwards and Haime, p. $09, pl. 14, figs. 2, 2a. 1873. Cyathophylloides Dybowski, p. 334, 379. 1940. _ Cyathophylloides Dybowski. Lang, Smith, and Thomas, p. 43. 1950. _ Cyathophylloides Dybowski, Bassler, p. 274 (in part). 1956. Cyathophylloides. Duncan, pl. 24, figs. 6a, 6b. 1956. Cyathophylloides Dybowski, Hill, p. F296, fig. 202,8a,3b? 1961. Cyathophylloides Dybowski, Flower, p. 83, pl. 43, figs. 1-10; pl. 44, figs. 1-5. Type species.-Cyathophylloides kassariensis Dybow- ski, 1873; by subsequent designation (Sherzer, 1891, p. 278). Island of Kassar, Estonia, from beds believed to be Upper Ordovician (Bassler, 1950, p. 274). Diagnosis.-Massive cerioid rugose corals having 12-14 smooth, simple lamellar major septa which meet axially, where they may be twisted but do not form a discrete axial structure or columella. Tabulae complete, highly variable from straight to arched distally with median sag or sagging slightly overall; widely spaced to closely set. Minor septa short to rather long. No dissepiments. Remarks.-Cyathophylloides is closely related to "Favistella'"' or Favistina Flower, a new generic term (Flower, 1961, p. 77) which, in adjustment of a nomencla- tural problem, may appropriately cover species pre- viously assigned to "Favistelle." Characters such as SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY 38 arching of tabulae and axial meeting of septa are, however, not overly constant in Cyathophylloides, which also, as here interpreted, may have some straight or nearly horizontal tabulae and whose major septa may in places be shorter, as in normal Favistina. Nonetheless, there is evidently a recognizable group of these Rugosa with the septal arrangement of Cyathophylloides which ranges from Late Ordovician into the Silurian and is represented by the lower Masket Cyathophylloides fergusont, n. sp. Cyathophylloides gothlandicus (Edwards and Haime) (1851, p. 809, pl. 14, figs. 2, 2a), one of the few described Silurian species, is insufficiently known internally. Bassler's (1950, pl. 18, figs. 10, 11) figures of gothlandicus do not show long, axially meeting septa. The strati- graphic horizon of gothlandicus is not known, but presumably the type material may have come from the vicinity of Visby, Gotland, in the lower part of the Silurian column. In a comprehensive study of Late Ordovician colonial Rugosa from the Montoya Dolomite of New Mexico, Flower (1961, p. 77-87) emphasized a close genetic rela- tionship of Cyathophylloides to Favistina, pointing up the survival of Cyathophylloides into the Silurian, where its species differ more widely from those of the shorter ranging Favistina. Cyathophylloides similar to fergusoni occurs in rocks of probable Silurian age in northern Eureka County, Nev. Float specimens which may represent either the Late Ordovician Hanson Creek Formation or the lower part of the Silurian Roberts Mountains Formation were col- lected by the writer at Section Ridge, Roberts Mountains (Duncan, 1956, explanation of pl. 24). Another float specimen from the same locality represents a seemingly undescribed genus with some features of Cyathophylloides but having an aulos and a single column of large peripheral dissepiments. Cyathophylloides fergusoni, new species Plate 5, figures 9, 10 Type material. USNM Silurian, Toquima Range, Nev. Diagnosis. cerioid Cyathophylloides forming large colonies. Wall thick for the genus, major septa meeting axially, minor septa very short; tabulae widely spaced, horizontal to arched. External _ features.-Coralla - developed as large lenticular masses more than 1 foot in diameter; weathered distal surfaces showing the thick-walled character and fairly uniform size of corallites. Transverse sections.-Major septa 12-14, fairly straight to axial part, smooth and of nearly uniform width without taper; some septa wavy toward the axis. In some individuals, two or more septa merge laterally, others terminate against the side of a contiguous longer septum. 159393; - Early In a few individuals, median dark line of a septum con- tinues across the axis into that of an opposite septum. No axially twisted intertwining of septal terminations as in some columellate Rugosa. Longitudinal sections.-Wall much thicker than tabulae and septa. Septa continuous lamellae, smooth and fairly even periaxially. Tabulae in part domed distally, in part nearly horizontal. No crenulation or pronounced downward bend of the periphery as in the genus Crenulites. Tabulae for the greater part widely spaced. _ septa - show _ well-defined medial dark line. Trabecular wall structure indistinct in longitudinal section. Comparison with related forms. figures (1950,.-pl. 17, figs. 10, 11) iof. the. type species, C. kassariensis, show more closely set tabulae with decided peripheral depression of tabulae not shown by ferguson. Major septa of kassariensis are more numerous and taper toward the axis. Cyathophylloides gothlandicus (Edwards and Haime) as figured by Bassler (1950, pl. 18, figs. 10,11) shows close-set tabulae and major septa which are thinner and do not reach the axis as, by definition, they would be expected to do in this genus. C. burksae Flower (1961, p: 83, pl. 43, figs. 1-10, pl. 44, figs. 1-5) of the Middle and Late Ordovician Montoya Group appears to be the closest to fergusoni, differing in its somewhat longer minor septa and in its distinctly arched, more closely spaced tabulae. Occurrence.-Lower Silurian, coral zone A, Masket Shale of Kay and Crawford (1964). Ikes Canyon, Toquima Range, Nev., locality M1088. Study material consists of one very large, nearly complete corallum, two partial coralla, and fragments of coralla. Genus PALAEOPHYLLUM Billings, 1858 1858. Palaeophyllum Billings, p. 168. 1956. - Palaeophyllum. Duncan, pl. 25, figs. la, 1b. 1959. - Palaeophyllum Billings. Hill, p. 4. 1961. Palaeophyllum Billings, Flower, p. 88. 1963. Palaeophyllum Billings. Oliver, p. G4. Type species.-Palaeophyllum rugosum Billings. Or- dovician, Black River or Trenton, Quebec, Canada. Diagnosis.-Phaceloid _ Stauriidae with - narrow peripheral stereozone and no dissepiments. Major septa long and simple, minor septa short; tabulae complete, commonly arched with axial depression. Forms very large colonies by lateral increase. Remarks.-All aspects of the morphology, taxonomy, and genetic relationships of Palaeophyllum have in re- cent years been dealt with by Flower, Hill, and Oliver. This phaceloid genus is probably closely related to the cerioid Favistina or Favistella and to Cyathophylloides. These nondissepimented colonial Rugosa are especially important in the higher Ordovician. In the Silurian, forms which appear to fit best in Palaeophyllum and Cyathophylloides are common in the Cordilleran belt; 34 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN these occur with other nondissepimented species having complete tabulae and similar growth habit, but having partly acanthine septa and therefore probably unrelated. Palaecophyllum sp. b Plate 3, figures 4, 5 A large silicified colony of this coral was collected by H. R. Cornwall and F. J. Kleinhampl from the lower part of the Silurian section at Bare Mountain near Beatty, Nev., in beds above the Ely Springs Dolomite. Palaeophyllum sp. b has 20 major septa, most of which extend more than half the distance to the axis; minor sep- ta are short. The tabulae are straight to slightly arched and lack axial sag. Palaeophyllum sp. b lacks the well-arched tabulae with axial sag of thomi (Hall), multicaule (Hall), and margaretae Flower; it has more major septa than the Silurian multicaule (Oliver, 1963, pl. 4, figs. 1, 2). Occurrence.-Lower part of the Silurian carbonate section on the east side of Bare Mountain, Nev., between Tarantula Canyon and Chuckwalla Canyon, locality M1085. The Great Basin Silurian coral zone of this occurrence has not been established; it probably repre- sents coral zone A. Palaecophyllum? sp. c Plate 2, figures 5, 6 Coral collections from the lower part of the Vaughn Gulch Limestone of the Owens Valley region, California, include a phaceloid species provisionally assigned to Palaeophyllum. Major septa number about 22; minor septa commonly exceed half the length of major septa. Major septa of most corallites are amplexoid and extend less than half the distance to the axis. Tabulae are straight or slightly arched. Occurrence.-Lower 300 feet of Vaughn Gulch Lime- stone, 125 feet stratigraphically above beds with Dalmano- phyllum sp. A. Associated with Heliolites and small in- determinate horn corals either near top of Silurian coral zone A or base of coral zone B. Northern Inyo Mountains, east of Kearsarge, at mouth of Mazourka Canyon, locality M1086. Family PYCNOSTYLIDAE Stumm, 1953 Reference genus and species.-Pycnostylus guel- phensis Whiteaves, 1884. Silurian, Guelph Dolomite; Ontario, Canada. Fasciculate rugose corals with subcylindrical mature corallites; septa low, continuous longitudinal ridges arising from narrow stereozone without acanthine spines. Tabulae complete, straight, unarched; no dissepiments. Reproduction by multiple wall (peripheral) offsets from calice interior. Trumpet-shaped flaring calices are characteristic. Long lamellar septa and arched tabulae of the Stauriidae and acanthine septa of the Tryplasmatidae are absent in this family, which otherwise presents homeo- morphic features. The slender fasciculate tryplasmids are externally similar and may, as with Tryplasma fascicularia Oliver, 1960, have fivefold axial increase (W. A. Oliver, written commun., 1969). Multiple calice offsets are probably less characteristic of the tryplasmids. The Zelophyllum group with sporadic acanthine spines are also homeomorphic; they are not known with multiple calice offsets as in the pycnostylids and seemingly do not produce the markedly flaring calices. The problematic Fletcheria is poorly understood. This Silurian pycnostylid has some cystose tabulae, and a rather thick wall with structure suggesting that of Syringopora (Duncan, 1956, pl. 25, figs. 6a, 6b). According to Duncan, Fletcheria lacks septa and does not have the inward- projecting free trabecular spines of tryplasmids. On the basis of Duncan's evaluation and the original figure of Edwards and Haime (1851, pl. 14, fig. 5), it appears some- what doubtful that the type species of Fletcheria is con- generic with Pycnostylus, as implied by Lang, Smith, and Thomas (1940, p. 112). Genera assigned to the Pycnostylidae are as follows: Pycnostylus Whiteaves, 1884 Fletcheria Edwards and Haime, 1851 Stylopleura, new genus (?)Cyathopaedium Schliiter, 1889 (?)Fletcherina Lang, Smith, and Thomas, 1955 ~ '(?)Maikottia Lavrusevich, 1967 Genus STYLOPLEURA, new genus Type species.-Stylopleura berthiaumi, n. sp., here designated. Silurian, Roberts Mountains Formation; Roberts Creek Mountain, Nev. Diagnosis. rugose corals with sub- cylindrical mature corallites joined by long, in some in- stances hollow, connecting processes. Septa low, longitudinal ridges, not differentiated into major and minor. Tabulae complete, straight, horizontal, and generally rather widely spaced. Septal stereozone narrow. No dissepiments. Multiple reproductive offsets, as many as 11, developed peripherally from the calice wall. Mature calice flaring. Remarks.-Stylopleura differs from Tryplasma and Zelophyllum in its lack of acanthine septa and in pos- sessing the connecting pillars. Fletcheria is believed to lack septal ridges and connecting processes. Among _ well-characterized - pycnostylid _ genera, Pycnostylus is closest to Stylopleura; but insofar as known, it does not have the connecting pillars and is, by definition, reported to produce only four calicinal offsets; this quadripartite offset pattern may not be a valid generic character. It is not unlikely the number of offsets is subject to considerable variation, as in Stylopleura and probably also in Fletcheria. Probably a pycnostylid related to Stylopleura is the SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY Asiatic genus Maikottia Lavrusevich, 1967, with type species M. turkestanica Lavrusevich from Upper Silurian rocks of the Turkestan Range. As figured by Lavrusevich (1967, pl. 3, figs. 4-6), Maikottia has a compact cerioid growth habit, whereas Stylopleura reveals both phaceloid and cerioid features, with partly open phaceloid characteristics predominant in some species. Maikottia is not known to possess lateral connecting pillars like those of Stylopleura. Maikottia _ resembling - Asiatic M. - turkestanica Lavrusevich (pl. 2, figs. 18; 14) has been collected by Michael Churkin, Jr., of the U.S. Geological Survey from Upper Silurian or Lower Devonian beds on the Porcupine River, half a mile upstream from the mouth of the Salmontrout River, Alaska. Stylopleura berthiaumi, new species Plate 3, figures 6-20 Type material. USNM 159382; paratypes 159381, 159383, 159384; figured specimen USNM 159385. Diagnosis.-Stylopleura forming loose phaceloid colonies with some mature cylindrical corallites of large size. Exterior with rugae and long, partly tubular con- necting processes which are fairly straight and join coral- lites at all angles. Peripheral calice offsets variable, numbering as many as 11. External features.-Some immature corallites ceratoid in lower part of colony, becoming cylindrical upward. Longitudinal grooves well defined; where wall is thin, these are true septal grooves. Within the loose colonies, generation of multiple calicinal offsets oblique becoming more nearly erect upward. Interspaces and corallite sur- faces occupied in places by attached Cladopora and Aulopora. External rugae, rather obtuse folds, reflected in- ternally as circular grooves. Large nonreproductive coral- lites flaring outward in a trumpetlike calice without offsets. Transverse sections.-Septal ridges within corallites from 44 to about 60 in mature corallites, some ridges with very minute surficial spines. Narrow stereozone showing no internal trabeculae in the silicified material available. No differentiation of septal ridges as major and minor. Septal ridges broadly rounded on the reflected calice plat- form. Longitudinal sections.-Tabulae complete, rather widely spaced. No trabeculae or spines visible in narrow stereozone of silicified specimens. Some tubular con- necting processes communicating with interiors of attached corallites through open pores. Reproductive offsets. growing inward and up- ward from the calice wall, numbering from five to 11. Offsets stand erect or axially inclined if the calice is flared; where vertical, offsets occupying most of the calice. Size of offsets fairly uniform within the calice. 35 Comparison with related forms.-No other described pycnostylid corals having long tubular connecting pro- cesses are known. The closest morphologically is Pycnostylus guelphensis Whiteaves of the Middle Silurian Niagara Series, reported to have quadripartite arrange- ment of interior calice offsets, not multiple as in Stylopleura; it is not known to have the connecting stolonal processes of Stylopleura. Occurrence.-Upper part of unit 3 of type section of the Roberts Mountains Formation (fig. 4), Silurian coral zone D; locality M1100 on upper Pete Hanson Creek, west side of Roberts Creek Mountain. Simpson Park Mountains near mouth of Coal Canyon, Silurian coral zone E; locality M1106, in upper coral-bearing limestone breccia. Toquima Range, at Ikes Canyon, Masket Shale of Kay and Crawford (1964); locality M1103 in Silurian coral zone D associated with large Verticillopora. Similar Stylopleura occurs in Silurian limestone at Bare Mountain near Beatty, Nev. In Chuckwalla Canyon (loc. M1099), dark-gray limestones containing Stylopleura lie in the lower part of the Silurian sequence (Cornwall and Kleinhampl, 1960) and are probably correlative with some part of the Roberts Mountains Formation. The Bare Mountain Stylopleura shows numerous lateral con- necting pillars, but available specimens do not reveal the multiple calice offsets of berthiaumi. Study material of Stylopleura berthiaumi consists of about 175 corallites from several coralla (loc. M1100), three corallites (loc. M1103), and one corallite (loc. M1106). Stylopleura nevadensis, new species Plate 2, figures 11, 12, 15, 16; plate 15, figures 1-4 Type material. -Holotype USNM 159431; paratypes USNM 159379, 159440, 159440a. Diagnosis.-Wide, subcylindrical, somewhat meander- ing corallites loosely to tightly appressed in large fasciculate coralla with few connecting pillars. Tabulae not distantly spaces. External features.-Holotype a large unsilicified lenticular head 10 inches in greatest diameter, having nonuniform corallites which vary considerably in size at distal surface. Corallum with cerioid tendency where closely appressed. Flaring calices not observed. Transverse sections.-At maturity, about 56 short un- differentiated septa, forming longitudinally continuous bladelike internal ridges. Septal stereozone medium to narrow, vaguely lamellar; epitheca discrete. Longitudinal sections.-Most tabulae straight to slight- ly wavy, terminating at inner stereozone margin. Trabeculae vague, nearly horizontal. The single observed lateral connecting pillar (pl. 15, fig. 4) is stereoplasm filled. Longitudinal sections prepared thus far show corallites in parts of the corallum, where they are tightly appressed and would not, therefore, be expected to reveal connecting processes. 36 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Reproductive offsets.-Three to five offsets, possibly more, filling most of calice. Comparison _ with _ related _ forms.-Stylopleura berthiaumi has narrower corallites, some of which have more widely spaced tabulae and more numerous offsets than nevadensis. Stylopleura nevadensis reveals fewer lateral connecting pillars, having more closely appressed corallites. Markedly flaring calice margins like those of some corallites of the type species have not been observed in nevadensis. Remarks.-The types of S. berthiaumi are silicified and were prepared by etching, such that connecting pillars are evident. The holotype of nevadensis is unsilicified and was studied internally by thin sections which show few of these lateral processes. It is possible that nevadensis is no more than a subspecies of berthiaumi. Occurrence.-Late Silurian, coral zone E in upper limestone beds of the Roberts Mountains Formation. Coal Canyon, northern Simpson Park Mountains, Nev., localities M1107, M1105, M1817. Late Silurian coral zone D, Ikes Canyon, Toquima Range, Nev., in association with large Verticillopora and Tonkinaria,locality M1103. Study material consists of the large complete corallum which is the holotype (USNM 159481, loc. M1107), two large coralla (locs. M1105, M1317), and one large corallum (loc. M1103). Stylopleura? sp. T. Plate 2, figures 7-10 This loosely appressed phaceloid-cerioid coral with un- usually large corallites is provisionally assigned to Stylopleura. The wall is much thickened stereo- plasmically, and its tabulae straight, mostly complete, and very closely spaced, in places being essentially in contact one upon another. Wall trabeculae are nearly horizontal; none extend internally as acanthine spines. Stylopleura? sp. T is not known to have the lateral connecting pillars of Stylopleura berthiaumi, n. sp., or S. nevadensis, n. sp. Its wall is thicker and its tabulae more even, much more closely spaced, and more nearly com- plete than in the Asiatic and Alaskan Maikottia, which also differs in having big arched tabellae and a uniformly cerioid growth habit. Occurrence.-Silurian or Lower Devonian limestone; Toquima Range, Nevada, Ikes Canyon vicinity, locality M1104. Collected by Kay and Crawford (1964). Family TRYPLASMATIDAE Etheridge, 1907 Reference genus and species. aequabile Lonsdale, 1845. Silurian, Ural Mountains, Russia. Solitary and colonial rugose corals with acanthine septa composed of vertical columns of trabecular spines pro- truding from a peripheral stereozone. Tabulae complete or partial; no dissepiments. In some species of Tryplasmatidae the trabecular septal spines are mostly buried in peripheral stereoplasm with only tips exposed; in others, they project obliquely in- ward and upward as long free spines where the stereozone is narrowed. Trabecular spines may develop also in radial rows on upper tabular surfaces to produce longer acanthine septa (Hill, 1986). Genera of the Tryplasmatidae recognized in the Great Basin Silurian are as follows: Tryplasma Lonsdale, 1845 Rhabdocyclus Lang and Smith, 1939 Palaeocyclus: Edwards and Haime, 1849 Zelophyllum Wedekind, 1927 The true Cystiphyllidae of the Silurian commonly have trabecular septal spines and, on this basis, have from time to time been considered as genetically related to this family. However, the pervasively dissepimented character of the Cystiphyllidae does not add support to this conclusion. Genus TRYPLASMA Lonsdale, 1845 1845. Tryplasma Lonsdale, p. 613. 1871. Pholidophyllum Lindstrim, p. 125. 1894. Spiniferina Penecke, p. 592. 1907. Tryplasma Lonsdale. Etheridge, p. 76-77. 1927. - Tryplasma Lonsdale. Lang and Smith, p. 461. 1927. Pholidophyllum Lindstrom. Wedekind, p. 25. 1927. Stortophyllum Wedekind, p. 30. 1936. Tryplasma Lonsdale. Hill, p. 204. 1940. Tryplasma Lonsdale. Lang, Smith, and Thomas, p. 135. 1940. Pholadophyllum Lang, Smith, and Thomas, p. 99. 1940. - Tryplasma Lonsdale. Hill, p. 405. 1950. _ Tryplasma Lonsdale. Schouppé, p. 80-84. 1952. Tryplasma Lonsdale. Stumm, p. 841-848. 1956. - Tryplasma Lonsdale. Hill, p. F312. 1960. _ Tryplasma Lonsdale. Oliver, p. 96. 1962a. Tryplasma Lonsdale. Oliver, p. 13. Type species.-Tryplasma aequabile Lonsdale, 1845; by subsequent designation (Etheridge, 1907, p. 42). Silurian, near Bogoslovsk, east of northern Ural Moun- tains, Russia. Diagnosis.-Solitary and fasciculate rugose corals with acanthine septa which are vertical columns of trabecular spines. Corallites elongate or subcylindrical. Septal stereo- zone medium wide to narrow. No dissepiments. Tabulae mostly complete, commonly straight and widely spaced. Remarks.-Tryplasma - and related corals with acanthine septa have been the subject of special studies by Hill (1936), Schouppé (1950), Stumm (1952), and Oliver (1960). Species of this genus are characteristic of Silurian deposits in Europe, Australia, and North America, and, as noted by Duncan (1956, p. 226-227; pl. 23, figs. 3a, 3b), they are among the common fossils in the Silurian of western North America. Oliver (1960, p. 96) noted that the range of Tryplasma extends into the Lower Devonian of Europe, Australia, and eastern North America. The genus Tryplasma, as understood at present, in- cludes species with considerably different growth habits, ranging from solitary forms with elongate coralla SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY 37 showing repeated rejuvenescence rims to bushy phaceloid colonies of slender, relatively smooth branches. The genus Tryplasma may be further subdivided taxonomically, on the basis of external form and growth habit, into units which may eventually be considered sub- genera. Two such form groups are recognized in the Great Basin Silurian: 1. Solitary-rugate Tryplasma with numerous reju- venescence rims like those of the Gotland T. hedstromi (Wedekind) and the Great Basin T. duncanae, n. sp. 2. Fasciculate cylindrical Tryplasma with loosely arranged slender subcylindrical, nearly smooth corallites like those of the Australian T. lons- dale Etheridge and the Great Basin T. newfar- meri, n. sp. Rugate Tryplasma of group 1 conceivably began with a form like the nontabulate Rhabdocyclus. Fasciculate members of group 2 may include species transitional to the colonial Zelophyllum, with less obviously acanthine septa. A third tryplasmid group has the growth habit of Polyorophe Lindstrom, 1882 (1882a), of the Gotland Silurian, which shows excessive lateral outgrowths of attachment. Certain rugose corals of the Lone Mountain Dolomite have the external appearance of Polyorophe, but internally reveal the nonacanthine structure of Entelo- phyllum. (See pl. 10, fig. 10.) Tryplasma of group 1 (solitary-rugate) Tryplasma duncanae, new species Plate 1, figures 26-28 1956. Type material. -Holotype USNM 159374; paratypes USNM 159375, 159376. Silurian, Roberts Mountains Formation, Nevada. Diagnosis.-Small solitary Tryplasma with elongate subcylindrical mature corallum having repeated re- juvenescence rims and prominent septal grooves. Calice deep and flat-bottomed with near vertical sides and septa which are vertical rows of short trabecular spines. Lateral attachment processes developed in nepionic and neanic growth stages. External features. -Attachment processes and talons present on the ceratoid early growth stages, after which the corallum becomes more nearly cylindrical with irregular- ly spaced and very prominent rejuvenescence rims and lo- cal changes in growth direction at rejuvenescence. Transverse section. wall a moderately thick stereozone in which the trabecular spines are largely buried. About 22 short acanthine septa. Longitudinal section. -Some widely spaced tabulae straight and complete; others slightly bowed, incomplete, and inclined at 45° or less. (?)Tryplasma Duncan, pl. 23, [ig. 3a. Comparison with related forms.-Tryplasma duncanae has much more numerous and prominent rejuvenescence rims, stronger septal grooves, and shorter septal spines than Tryplasma nordica Stumm from the Silurian of Maine and Quebec. T. duncanae resembles externally both T. prava (Hall) Stumm of the Louisville Limestone, Ky., and T. hedstromi (Wedekind) of the Gotland Silurian, which have numerous rejuvenescence rims. The similarity to hedstrémi seems particularly close, but the septal spines of duncanae are shorter, and the tabulae are more widely spaced. Occurrence.-Upper beds of unit 3, Roberts Mountains Formation; Late Silurian, coral zone D. Northwest side of Roberts Creek Mountain, Nev., upper Hanson Creek drainage basin, locality M1100. Study material consists of 14 corallites. Tryplasma of group 2 (fasciculate-cylindrical) Tryplasma newfarmeri, new species Plate 2, figures 1-4 Type material.-Holotype USNM 159377; Silurian, Roberts Mountains Formation. Diagnosis.-Compound Tryplasma with slender small, very elongate, loosely phaceloid cylindrical corallites re- producing by calicinal offsets at the periphery. Wall moderately thick with no prominent rejuvenescence rims, lateral connections, or attachments. Tabulae mostly com- plete and widely spaced. External features.-Fairly straight cylindrical coral- lites; abundant annular incremental striations, but no conspicuous rejuvenescence rims, and no septal grooves. No calice features on available specimens. Transverse sections. -About 40 acanthine septa; septal spines short, set in a moderately wide stereozone. Longitudinal sections.-Short septal spines projecting axially and distally within and beyond stereozone. Most tabulae widely spaced and complete or nearly complete; many nearly straight, others slightly bowed. Well-defined columns of spine bases within the stereozone seen in tangential sections. Reproductive offsets.-Calicinal offsets observed in longitudinal section arise at stages where the calice is of greater than average width; several offsets developed con- currently within some individual calices. Comparison with related forms. newfarmeri, n. sp., is a more slender form than T. nordica Stumm, which is solitary (Oliver, 1962a, p. 13). T. lonsdalei Etheridge is an Australian Silurian colonial species (Hill, 1940, p. 406) similar to new farmer, but T. lonsdale? appears to differ by having more closely spaced tabulae, and according to Hill, its corallites may be connected by processes. Occurrence.-Lower beds of unit 3, Roberts Mountains Formation; Middle Silurian, coral zone C. Northwest side of Roberts Creek Mountain, Nev., upper Hanson Creek 38 drainage basin, locality M1102. Study material consists of one very large corallum and fragments of other coralla. Tryplasma sp. R Plate 1, figures 29, 30 This subcylindrical species, known only as isolated corallites, has especially long and robust trabecular spines; rows of more slender spines occur on upper sur- faces of slightly undulant tabulae. In transverse thin sec- tion the septal spines lack uniformity of length and weight. Occurrence.-Unit 3 of Roberts Mountains Formation. Roberts Creek Mountain, Nev., locality M1101. Genus RHABDOCYCLUS Lang and Smith, 1939 1850-54. - Palaeocyclus fletcheri Edwards and Haime, p. 248; pl. LVIL, figs. 3-34. 1851. Palaeocyclus fletcheri Edwards and Haime, p. 205. 1873a. Acanthocyclus Dybowski, p. $38, 359; pl. 1, figs. 10, 10a, 10b [not Lucas, 3 1848-44]. 1927. Acanthocyclus fletcher? (Edwards and Haime). Lang and Smith, p. 450, figs. 1, 2. 1927. Acanthocyclus porpitoides Lang and Smith, p. 486, fig. 16. 1936. Acanthocyclus porpitoides Lang and Smith. Hill, p. 196; figs. 9, 12, 15, 19; pl. 29, fig. 37. 1936. Acanthocyclus fletcheri. Hill, p. 199, fig. 21. 1939. Rhabdocyclus Lang and Smith, p. 152. 1940. Rhabdocyclus. Lang, Smith, and Thomas, p. 113. 1956. Rhabdocyclus Lang and Smith. Hill, p. F311, fig. 213. 1a, 1b. Type species.-Palaeocyclus fletcheri Edwards and Haime, by author's designation (Lang and Smith, 1927, p. 450; Lang, Smith, and Thomas, 1940, p. 113). Silurian, Wenlock Limestone, Dudley, England. Diagnosis.-Turbinate or curved trochoid solitary ru- gose corals with acanthine septa and lacking tabulae and dissepiments. Deep calice extending to nepionic tip. Remarks.-Rhabdocyclus is morphologically inter- mediate between Palaeocyclus and Tryplasma. There is, however, no evidence of evolutionary lineage. In Rhabdocyclus the initial cone is usually excentric, whereas in Palaeocyclus it is commonly near the center. Some individuals of typical porpita do show an excentric initial cone and patellate convexity of the basal disk. Tryplasma is distinguished from Rhabdocyclus by development of complete tabulae and could be derived from the latter. The type species of Rhabdocyclus is reported to come from the Wenlock Limestone of Dudley, England. The Hidden Valley specimens here dealt with occur in the lower part of that formation in coral zone A and are be- lieved to be Lower Silurian (Llandoverian). 'In Edwards and Lucas, 1843-44. SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Rhabdocyclus sp. B Plate 1, figures 24, 25 Large silicified trochoid individuals of this form col- lected at Bare Mountain, Nev., have about 74 acanthine septa in which the trabecular spines are especially coarse. There is an incipient differentiation into major and minor septa. The exterior is longitudinally grooved and has well- developed rugae. This species resembles R. sp. d but is much larger, and its trabecular spines are coarser. Occurrence.-In dark-gray Silurian limestone about 150 feet stratigraphically below contact with light-gray dolomite. Study material of sp. B consists of four silicified coralla. Bare Mountain quadrangle, Nevada, near mouth of Chuckwalla Canyon, locality M1099. Rhabdocyclus sp. d Plate 1, figures 22, 23 Small silicified specimens assigned to this genus were collected by J. F. McAllister from the lower unit of the Hidden Valley Dolomite at Whitetop Mountain, north- ern Panamint Range. Rhabdocyclus sp. d is curved trochoid and has about 26 major septa with coarse trabecular spines; minor septa are short and comprise rather widely spaced columns of spines. The septal stereozone is medium wide to narrow. Lateral projections are present on the exterior. Edwards and Haime's figures of R. fletcheri show more numerous primary septa and a reflected calice rim not present in sp. d. Large individuals of Rhabdocyclus sp. B from the Silurian of Chuckwalla Canyon, Bare Mountain, Nev., reveal more numerous acanthine septa and a trochoid corallum. Occurrence.-Lower part of the Hidden Valley Dolomite; Early Silurian, coral zone A. Whitetop Mountain, northern Panamint Range, locality M1096. Study material of sp. d consists of two silicified coralla and fragmentary coralla. Rhabdocyclus sp. K Plate 15, figures 5-9 A curved-turbinate to near-patellate Rhabdocyclus re- presentative of this Silurian tryplasmid genus was col- lected from the Laketown Dolomite of the Confusion Range, Utah, by A. J. Boucot. Its acanthine septa are dif- ferentiated as major and minor, with 26 major septa. Columns of trabecular nodes form minor septa. This species possesses un excentric apex, the apical cone flar- ing abruptly in the neanic growth stage, followed by abrupt curvature in some individuals. Weak obtuse long- itudinal ribs are crossed by fine incremental lines and rugae on the exterior. Rhabdocyclus sp. K resembles the British type species fletcheri more closely than either of the other two Great SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY Basin forms. Rhabdocyclus sp. K differs from fletcheri in having fewer septa but is very similar in its septal character and exterior ornamentation. Occurrence.-Laketown Dolomite. Confusion Range, Utah; Kings Canyon, Conger Mountain quadrangle, locality M1137. Study material consists of six silicified coralla. Genus PALAEOCYCLUS Edwards and Haime, 1849 1767. Madrepora porpita Linnaeus, p. 1272 (in part). 1849. Palaeocyclus Edwards and Haime, p. 71. 1850-54. Palaeocyclus Edwards and Haime, p. xlvi, p. 246-248. 1851. Palaeocyclus Edwards and Haime, p. 203-206. 1927. Palaeocyclus porpita. Lang and Smith, p. 485. 1936. Palaeocyclus Edwards and Haime. Hill, p. 193. 1936. Not Porpites Schlotheim (in part). Wells, p. 127. 1937. Paleocyclus Edwards and Haime. Bassler, p. 190, pl. 30, figs. 1-4. 1940. Palaeocyclus Edwards and Haime. Lang, Smith, and Thomas, p. 94. 1940. Porpites Schlotheim. Lang, Smith, and Thomas, p. 108. 1956. Porpites Schlotheim. Hill, p. F312. Type species. -Madrepora porpita Linnaeus, 1767 (by monotypy). Silurian, Gotland. Uncertainty has long ex- isted regarded validity of the name Palaeocyclus as op- posed to Porpites Schlotheim, involving the status of Schlotheim's syntypes (Wells, 1986, p. 127; Lang, Smith, and Thomas, 1940, p. 103-104). W. A. Oliver, Jr. (written commun., 1969), has pointed out that unless there was an earlier selection of a genolectotype for Porpites, Wells fixed the genus by selecting P. globulatus in 1986. Accordingly, the selecting of another species by Lang, Smith, and Thomas in 1940 is invalid. Porpites globulatus is a scleractinian, and, thus, Porpites is not available as a name for a Paleozoic coral. Diagnosis.-Small discoid tryplasmid rugose corals with flat to slightly patellate epithecal base having a small central cone and concentric incremental rings. Thick beaded septa with free, broadly convex peripheral edges; distal margins of major septa gradually sloping toward bottom of deep calicular pit. Minor septa commonly more than one-half the length of major septa. No fossula, tabulae, or dissepiments. Septal pattern distinctly radial. Remarks.-The septal beads or nodes are distal ends of large trabeculae. As seen on lateral surfaces of major septa, these trabeculae rise obliquely from the base as external ridges and slope toward the axis with increasing steepness. (See Hill, 1986, figs. 14-17.) The nodes may be very prominent or even spinose, and toward the periphery they become transverse, like yardarm carinae of other Rugosa. In some species the basal disk extends laterally as a flange beyond the exposed septa. Generally, most of the central cone has been removed by abrasion. Palaeocyclus porpita, the type species, occurs in the Lower Visby Marl of Gotland, regarded as late Llandoverian Lower Silurian. At Gotland Palaeocyclus is not known to range higher. In England this genus is re- 39 ported in the Wenlockian (Hill, 1986, p. 193). Reported oc- currences of the genus in North America (Bassler, 1937, p. 190) range from the Silurian Clinton Group and Manistique Dolomite to the Devonian of the Porcupine River, Alaska. Except for the Great Basin forms here dealt with these American forms differ considerably from porpita, Devonian assignment of the Alaskan form is certainly in need of review. Palaeocyclus porpita subsp. mcallisteri, n. subsp. Plate 1, figures 12-15, 17 1952. Porpites porpita. McAllister, p. 16. Type material. -Holotype USNM 159365; paratypes USNM 159364, 159366, 159867. Early Silurian, coral zone A; Ubehebe district, California. Diagnosis.-Septa thick, with coarse noding for the species porpita; septal thickness slightly exceeding length of radial interspaces between nodes. Transverse features. major septa, numbering 20-22, tapering gradually toward axis, where some of the attenuated projections meet. (This feature may be observed through the transparent basal disk of worn in- dividuals of Gotland porpita.) Minor septa the length of major septa. Trabecular nodes on upper edges of the major septa number 10 to 12. Central pit reaching basal plate. Longitudinal features. broken in two radially, with a radial profile of septa with curve inflection of distally convex major septa usually closer to periphery than to axis. Individuals with evenly rounded septal pro- file and steep-sided axial calice pit predominate. Sides of major septa show 10-12 slightly curved, thick trabecular spines standing almost vertical near axis, but toward the corallite periphery rising in a gentle arc inclined axially 30°-40°. Fine structure. -Available silicified material lacks fine structure. Hill's classic studies of well-preserved Gotland porpita material (1936, p. 193-196) deal with minute details of trabeculae and are basic to understanding of acanthine septal structures among Rugosa. Comparison with other species. -As noted above, the Hidden Valley form is regarded as conspecific with the Gotland porpita but is sufficiently different morphologically to warrant its classification as a geographic subspecies. Of described American species (Bassler, 1937, p. 190, pl. 30 figs. 5 -12), all are too poorly known for meaningful comparison. P. Michiganensis Bassler of the Manistique Dolomite appears to have more slender, wider spaced septa,|P. rotuloides (Hall) of the Clinton Group has fewer septa, and P. kirby? Meek of supposedly Devonian strata at the Porcupine River, Alaska, is a larger form with more numerous and more closely spaced, seemingly unbeaded septa. The last may re- present a different genus and requires restudy. 40 The undescribed Confusion Range, Utah Palaeocyclus resembles typical porpita but is, on the whole, smaller. Several of the individuals are slightly patellate, like variants of the Gotland porpita. Some have a peripheral flange on the basal disk. Occurrence. -Lower Silurian, Great Basin coral zone A. Basal beds of unit 1 in the lower part of Hidden Valley Dolomite. Whitetop Mountain, Northern Panamint Range, locality M1096. Southern Andy Hills, northern Panamint Range. Similar Palaeocyclus occurs in the Confusion Range, Utah, locality M1129, and in the Ruby Mountains, Nev. (pl. 15, fig. 10), 3 miles northeast of Mitchell Ranch, Sherman Mountain quadrangle, locality M1886. Study material is as follows: Whitetop Mountain (M1096), 25 coralla; Andy Hills, two coralla; Confusion Range (M1129), six coralla; Ruby Mountains (M1336), two coralla. Genus ZELOPHYLLUM Wedekind, 1927 1927. - Zelophyllum Wedekind, p. 34-85, pl. 5, figs. 1-5; pl. 6, figs. 11-13. 1956. Zelophyllum Wedekind. Hill, p. F312, fig. 213.7. Type species. -Zelophyllum intermedium Wedekind, by author designation. Silurian, Hiogklint, Gotland, Sweden. Diagnosis.-Solitary and colonial nondissepimented rugose corals with cylindrical corallites of large and medium size. Wall moderately thick, tabulae straight to undulant and unarched. Septa short or stubby, usually tapering abruptly from wall; in places, walls thinned and studded with acanthine trabecular spines. Outer surface fairly even, with longitudinal grooves and no pro- nounced rugae. Remarks.-Silurian - species from - Alaska - show especially well the acanthine septal spines and possible tryplasmid relationships of this coral. In some in- dividuals the large trabeculae are buried in the wall stereome and do not project inward as free spines. Dif- ferentiation of septa as major and minor may be un- recognizable in those forms with stout abruptly tapering very short uniform septa. Other cylindrical Silurian genera with which Zelophyllum may be confused are Palaeophyllum and Stylopleura. Palaeophyllum is more slender, has lamellar septa of greater length, and usually possesses well-arched tabulae, whereas tabulae of Zelophyllum are normally straight. Stylopleura has a trumpetlike calice, has lateral connections between coral- lites, and is not known to have acanthine septal spines. Zelophyllum is common in the Silurian of the Pacific Border province, as in southeastern Alaska and the Klamath Mountains of northern California. In the Great Basin most of the larger nondissepimented rugose corals of this general construction are assigned to the new genus Stylopleura. SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Occurrence.-Nondissepimented corals possibly repre- senting Zelophyllum occur in the Great Basin, but the wall structure is generally not well enough known to con- firm this generic assignment. Corals with abundant acanthine septa and cylindrical corallites are placed in Tryplasma. Possible Zelophyllum occurs at Dry Canyon, Toyabe Range, 8 miles south of Austin, Nev., in the Thomas Range, Utah, and in the east Tintic Mountains of Utah. Family KODONOPHYLLIDAE Wedekind, 1927 Representative genus and species. -Kodonophyllum milne-edwardsi (Dybowski). Silurian; Gotland, Sweden. Solitary and colonial rugose corals with long septa, a very wide stereozone, no dissepiments, and a tabularium of flat tabulae or arched tabellae which may combine with septal ends to produce an axial structure. Two subfamilies are recognized: Kodonophyllinae and Mycophyllinae. Subfamily KODONOPHYLLINAE Wedekind Fasciculate colonial and platelike solitary rugose corals with the family characteristics and arched tabulae and tabellae which combine to form an axial structure. Genera included in this subfamily are Kodonophyllum Wedekind and Schlotheimophyllum Smith. Genus KODONOPHYLLUM Wedekind, 1927 1758. _ Madrepora truncata Linnaeus (in part), p. 795. 1873b. Streptelasma milne-edwardsi Dybowski, p. 409-410, pl. xiii, figs. 5-12. 1927. _ Kodonophyllum Wedekind, p. 9-10, 35-36, pl. 5, figs. 5-11. 1927. _ Patrophontes Lang and Smith, p. 456-457, figs. 8-9. 1929. _ Kodonophyllum Wedekind; Smith and Tremberth, p. $67- 370, pl. viii, figs. 5-7. 1937. - Kodonophyllum Wedekind; Soshkina, p. 52-55 (in part), plo ix.. 'figs. 4, pl..x. figs. 8-6; pl.. xxi, figs. 1, 2. 1940. _ Codonophyllum Lang, Smith, and Thomas, p. 39. 1956. _ Kodonophyllum Wedekind; Hill, p. F271, fig. 184,la, 1b. 1962b. Kodonophyllum Wedekind; Oliver, p. 23-26, pls. 9-13. 1964. _ Kodonophyllum Wedekind; Stumm, p. 26, pl. 25, figs. 9-14. Type - species. -Streptelasma _ milne-edwardsi Dybowski, 1873; Silurian, Gotland. Diagnosis.-Solitary and compound rugose corals with trochoid to ceratoid and turbinate corallites. Septa thickened peripherally to form a wide sterozone. Major septa extending to axis, where they are involved with tabulae to form an axial structure thickened by stereo- plasm. Tabulae sloping downward from axis. No dissepiments. Remarks.-According to Smith and Tremberth (1929, p. 368, 369), Dybowski's Streptelasma milne-edwardst is a synonym of Madrepora truncata Linnaeus, 1758, which occurs at Hall, Lilla Karlso, Gotland, and other localities, in beds of Wenlockian and Ludlovian age, principally the last. In England this species is reported by Smith and Tremberth from the Wenlock only. The relationship of Kodonophyllum to Schlotheimo- SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY phyllum requires clarification; they appear to be distinct genera with quite different growth habits, and they occur in different parts of the Gotland section. The Great Basin Kodonophyllum mulleri has a large columellar boss projecting up in the calice and is more nearly ceratoid than trochoid. Kodonophyllum mulleri, n. sp. Plate 4, figures 3-7 Type material. -Holotype USNM 159386, 159386a-b; paratype USNM 159389. Diagnosis.-Medium to large solitary Kodonophyllum with trochoid to ceratoid corallum and deep calice with columellar boss. Transverse sections.-Major septa numbering about 48, smooth and fairly straight except as they approach the axis; septa thickened somewhat throughout but excessively in the wide septal stereozone and within the axial structure. Minor septa less than half the length of major; in some individuals projecting axially beyond stereozone. No fossula. Transverse interseptal traces are downward-inclined tabulae, not dissepiments. Longitudinal sections.-Tabularium more than half the corallite diameter. Stereozone width about one-fifth the corallite diameter. Tabulae close-spaced, dis- continuous, arched steeply to axial structure, where they are obscured by intersection with stereoplasm and septal ends. Marginal tabellae flat or axially inclined. Trabeculae in septal stereozone inclined peripherally. Large calice boss with axial depression. Comparison with related forms. truncatum of the Gotland Silurian is a colonial species and has a narrower tabularium with a less robust axial structure and wider. septal stereozone.. K. richteri Wedekind, also of the Gotland Silurian, has fewer major septa and more widely spaced, more nearly complete, arched tabulae. An undescribed species from the upper- most Gazelle Formation of the Klamath Mountains, Calif., differs in having somewhat nodose or spiny septa. Occurrence.-In limestone breccia near the top of the Silurian section; coral zone E. Coal Canyon, northern Simpson Park Mountains, Nev., locality M1107. Study material consists of three partial coralla. Subfamily MYCOPHYLLINAE Hill, 1940 Large solitary platelike and subcylindrical rugose corals with the family characteristics and having straight, usually unarched, and complete tabulae with no axial structure. Genera included in this subfamily are as follows: Mucophyllum Etheridge, 1894 Chlamydophyllum Po€ta, 1902 Pseudamplexus Weissermel, 1897 (?)Briantia Barrois, 1889 Other Rugosa, having similar growth habit but dif- 41 fering in details of internal structure, have been con- sidered in connection with the Kodonophyllidae. Among these are Naos (Lang, 1926) and Craterophyllum (Foerste, 1909), which are dissepimented. The name Chonophyllum has been applied erroneously to corals now classified as Schlotheimophyllum (Smith, 1945, p. 18). Genus MUCOPHYLLUM Etheridge, 1894 1894. - Mucophyllum Etheridge, p. 11-18, pls. iii, iv. 1926. - Mucophyllum. Lang, p. 431, 433; pl. xxx, figs. 7, 8. 1940. - Mycophyllum. Lang, Smith, and Thomas, p. 87. 1940. - Mucophyllum crateroides Etheridge. Hill, p. 400; pl. 12, figs. 1. 2. 1940. _ Not Mycophyllum liliiforme (Etheridge). Hill, p. 401, pl. 12, figs. 3-6. 1945. - Mucophyllum crateroides Etheridge. Smith, p. 19. 1949. - Mycophyllum Etheridge. Stumm, p. 49, pl. 23, figs. 9, 10. 1956. - Mucophyllum Etheridge. Hill, p. F277, fig. 189.32. Type species. -Mucophyllum crateroides Etheridge, 1894, by monotypy. Silurian, Hatton's Corner, Yass River, New South Wales, Australia. Diagnosis. -Large discoid or patellate to turbinate, usually solitary, rugose corals with broad calice platform, reflexed margin, and flat-bottomed central pit. Numerous thick septa in contact laterally to form a wide stereozone, : some longer septa reaching the axis. Tabulae medium wide or narrow, complete, and straight to undulant. No dissepiments. Longitudinal section showing fine, near- horizontal incremental layering of thick stereozone tran- sected by near-vertical trabecular pillars. Radial grooves of calice platform overlying sutures between thickened septa. Remarks.-The layered and usually thick stereo- plasmic peripheral disk of Mucophyllum is the most dis- tinctive feature of this genus. Schlotheimophyllum, with similar growth habit, has a comparable, though possibly less dense, stereozone and differs in possessing a more com- plex axial structure like that of Kodonophyllum. Naos Lang, 1926 (possibly a synonym of Craterophyllum Foerste, 1909), differs in having well-defined dissepi- ments and zigzag septa which break up peripherally in naotic fashion. Chonophyllum Edwards and Haime, 1850, has been confused with all of these genera; as here in- terpreted, this coral has separate generic status. Other forms which might be confused externally with Mucophyllum or Chonophyllum having a trumpet- shaped calice are longer stemmed corals, some of which are referrable to the new genus Stylopleura. The longest septa of Mucophyllum extend in part be- yond the stereozone and become involved with tabulae in an incipient axial structure, as in M. oliveri, n. sp.; this structure does not become complex like that of Schlotheimophyllum. Occurrence.-The type species from Yass River, Australia, occurs in beds of high Wenlockian or Ludlovian age (Hill, 1940, p. 388). The Klamath Moun- 42 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN tains representatives are of equivalent age; those from the Great Basin are believed to be Ludlovian. Mucophyllum oliveri, n. sp. Plate 5, figures 1-6 Type material. USNM 159390; paratype USNM 159391. Diagnosis.-Mucophyllum _ with _ multiple, _ fine horizontal layering of massive stereozone and close-spaced fine trabecular pillars normal to layers. Tabulae narrow, nearly horizontal, and undulant; thickened where in- volved with long septa. Traverse, sections. -About 76 septa, most of which ex- tend to the tabularium; a few attenuated and very ir- regular twisted extensions reaching or curving around the axis. Septa straight and even within the wide stereozone; prominent dark radial bands are sutures between thickened septa. Enlargement of transverse section reveals a closely spaced pattern of trabecular rods in septa dis- posed normal to the section. Ends of these trabecular rods number about 30 per square millimeter. Ends of rods com- monly revealing clear calcite interior and shadowy dark peripheral zone, suggesting initially tubular construction. Longitudinal sections. -Horizontal laminae of massive stereozone reflecting curvature of calice platform, bending as they approach the tabularium to a steep axial in- clination. Laminae alternating light and dark, varying considerably in thickness, and averaging about six per millimeter. Trabecular rods normal to laminae, becoming inclined peripherally near the tabularium. Tabulae numbering about 16 per centimeter, wavy and only in part complete, some terminating against other complete tabulae. Some tabulae thickened throughout, with exces- sive swelling close to the axis, where septa intersect. Comparison - with related forms.-Mucophyllum oliveri resembles an undescribed species in the Gazelle Formation of the Klamath Mountains, Calif. The Gazelle form possesses a similar calice platform, but layering of the massive stereozone is more widely spaced. The Gazelle species has thickened horizontal tabulae but lacks the tabular undulation and thickened septal intersections, being in this regard more typical of Mucophyllum. Mucophyllum crateroides, the type species, has a wider tabularium and straight tabulae with seemingly less close- ly spaced horizontal stereozone laminae. Certain features of the tabularium and axis of M. oliveri are in a sense more suggestive of the genus Schlotheimo- phyllum than of typical Mucophyllum because of the development of an incipient axial structure. Compared in detail with a longitudinal section of S. patellatum, the type species figured by Lang (1926, pl. xxx, fig. 5), there is little close similarity. In Schlotheimophyllum the mar- ginal parts of the tabulae are peripherally inclined, and these tabulae are strongly arched. A fairly complex wide axial structure is formed in Schlotheimophyllum by the meeting of the numerous major septa and their twisted in- volvement with arched tabulae. In S. patellatum the stereozone trabecular rods show steep axial inclination over a large part of the peripheral disk; this is not a feature of Mucophyllum. Occurrence.-Limestone breccia zone near the top of the Silurian section coral zone E. Coal Canyon, northern Simpson Park Mountains; locality M1108. Study material consists of two nearly complete coralla and three partial coralla. Family ARACHNOPHYLLIDAE Dybowski, 1873 a Reference genus. -Arachnophyllum Dana, 1846. These Early and Middle Silurian astraeoid and thamnostraeoid rugose corals resemble in growth habit certain Devonian Disphyllidae and Phillipsastraeidae, among which are Billingsastraea and Pachyphyllum. The superficial similarity is one of gross morphologic con- vergence and is not indicative of genetic relationship. Dybowski (1873a, p. 339), in naming the family, erroneously included Devonian homeomorphs and strangely enough, assigned his Darwinia, a homonym and synonym of Arachnophyllum, to the Ptychophyllidae. It appears doubtful that among described corals there are other genera sufficiently close morphologically to warrant their inclusion in the Arachnophyllidae. However, the single genus as it stands is highly diverse (Stumm, 1964) and may lend itself, on detailed study, to at least subgeneric division. Genus ARACHNOPHYLLUM Dana, 1846 1839. Acervularia baltica Schweigger (in part). Lonsdale,'pl. XVI, figs. 8b-e. 1846. Arachnophyllum Dana, p. 186, text fig. 1. 1848. Arachnophyllum Dana, p. 360. 1850-54. Strombodes typus (McCoy). Edwards and Haime, p. 293, pl. 71, figs. 1, la, 1b, 2a. 1873a. Darwinia Dybowski, p. 404, pl. II, figs. 8, 8a. 1927. Arachnophyllum typus (McCoy). Lang and Smith, p. 452, figs. 5, 6, 7. 1937. Darwinia Dybowski. Soshkina, p. 57, pl. XVI, fig. 5. 1940. Arachniophyllum; Lang, Smith, and Thomas, p. 19. 1949. Arachnophyllum pentagonum (Goldfuss). Amsden, p. 104, pl. XXVI, figs. 1-6. 1956. Arachnophyllum Hill, p. F274, fig. 187.3a, 3b. 1964. Arachnophyllum Dana. Stumm,. p. 30, pls. 20, 21. Type species. baltica Schweigger (in part), Lonsdale, 5 1839, pl. XVI, figs. 8b-e, according to Lang, Smith, and Thomas (1940). Lang and Smith (1927, p. 452) and Lang, Smith, and Thomas (1940, p. 19) gave localities for the type species at Wenlock and Dudley, England, Silurian Wenlock limestone. Diagnosis.-Astraeoid or thamnastraeoid rugose corals building horizontally layered colonies in which in- dividual corallites lack a discrete wall but on the distal sur- face are defined by elevated rim and axial pit, with or with- 'In Murchison (1839). "In Murchison (1839). Wi Otr ias ias de W i ea SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY out crateriform margin. Septa thin, commonly with abun- dant angulation carinae; longer major septa reaching the axis. Dissepiments very numerous, largely with near- horizontal bases in a wide dissepimentarium. with tabellae arched distally or rather flat. Longitudinal sec- tions showing groups of vertical trabecular thickenings commonly defining septal traces. Remarks.-These corals with shallow platform calice and axial pit have frequently been classified as "Strombodes," the presently accepted type of which is a phaceloid species (Strombodes stellaris Linnaeus) dif- fering in many other structural details. Described Arachnophyllum species show a considerable diversity with respect to size range of the flat dissepiments, con- tinuity and carination of septa, prominence of calice rims, and arching of tabellae. In some species the tabularium is weakly defined and the arching much less distinct than that shown in Dybowski's (1873a, pl. 2, fig. 8) drawing of speciosa. Peripheral discontinuity of septa and develop- ment of outer zones of irregular lonsdaleioid dis- sepiments is a characteristic of some species. As at present understood, Arachnophyllum is mainly a Lower and Middle Silurian coral. The genus was reported from the Llandoverian red marls below the Gotland Visby Marl by Lindstrom (1884, p. 7), and in North America it ranges up-ward to the Brownsport and the Louisville For- mations. In the Great Basin, Arachnophyllum has been found thus far only in Silurian coral zone A, which is con- sidered Early Silurian Llandoverian. Arachnophyllum kayi, n. sp. Plate 5, figures 7, 8 Type material. -Holotype USNM 159892; lower part of the Silurian section, Ikes Canyon, Toquima Range, Nev. Diagnosis.-Corallites small for the genus, with no lonsdaleioid dissepiments; septa thin, continuous into ad- jacent corallites, with numerous angulation carinae in- creasing in complexity toward the axis. Dissepiments mostly small; tabularium poorly differentiated. External features.-Upper surface of colony with medial crateriform rims; no elevated rims observed between corallites. Transverse section.-Ten major septa, most extending to axis; minor septa long, terminating just within tabularium margin. Angulation or zigzag carinae numerous, especially pronounced toward inner edge of dissepimentarium. Septal extensions wavy or twisted, but noncarinate in tabularium. Dissepiment traces vaguely defined, none are lonsdaleioid. Longitudinal section. columns of small, low dissepiments with more or less horizontal bases; larger globose dissepiments uncommon, and pattern more uniform than in most other described species. No arching of tabellae or indication of arching at rims between corallites. Septal traces showing carinal spurs. Shadowy 43 near-vertical trabeculae defining septal traces; shadowy trabeculae present elsewhere in larger groups. Comparison with related forms.-The upper surface of Arachnophyllum speciosa (Dybowski) from Kattentak, Estonia, resembles that of but Dybowski's figure does not show the minutely zigzag septa. Soshkina's (1937, pl. 16, fig. 5) figure of a similar form also referred to Dybowski's speciosa comes from the Ural Mountains in strata reported to be Wenlockian. Arachnophyllum - typus (McCoy) of the British Wenlock, as figured by Edwards and Haime (1850-54, p. 293, pl. 71, figs. 1-1b), differs in having wall rims on the upper surface and sporadic larger globose dissepiments. Of American species, the Brownsport pentagonum of Amsden (1949, p. 104, pl. 26, figs. 1-6) also differs in having wall rims and sporadic large globose dis- sepiments. Of the six species described from the Louisville Limestone (Stumm, 1964, p. 30, pls. 20, 21), most have wall rims, discontinuous septa, and large globose or lonsdaleioid dissepiments in a wide peripheral zone. Occurrence.-Lower part of the Silurian limestone section, in Masket Shale of Kay and Crawford (1964); Silurian coral zone A. Ikes Canyon, Toquima Range, Nev., locality M1088. Study material consists of two partial coralla and frag- ments of other coralla from Ikes Canyon (M1088) and a partial corallum from Whitetop Mountain, northern Panamint Range (M1096). Family LYKOPHYLLIDAE Wedekind, 1927 Representative - genus - and - species. -Phaulactis cyathophylloides Ryder, 1926. _ Silurian, Wenlockian, Slite Group, Vastergarn, Gotland, Sweden. Diagnosis.-Medium and large solitary rugose corals with multiple columns of small to medium dissepiments, a tabularium which may not be abruptly differentiated at margin from dissepimentarium, with septa commonly thickened and laterally in contact into or beyond neanic growth stage, and with no well-defined fossula in advanced growth stages. Remarks.-These well-dissepimented Silurian corals have some features of the Devonian Halliidae, but in the advanced growth stages they do not, like the Halliidae, have a well-defined fossula, and they lack the lonsdaleioid dissepiments of the Papiliophyllum subgroup. The Devonian Bethanyphyllidae are also very similar to these Silurian genera and may be difficult to distinguish; in general, the Bethanyphyllidae of the Great Basin pro- vince have more irregular, wavy, thin mature septa, a more distinct though not always sharp fossula, and more numerous straight tabulae; among Bethanyphyllidae, the early septal thickening does not persist in growth beyond fairly early neanic stages. Genera classified under the Lykophyllidae are as follows: 44 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Phaulactis Ryder, 1926 Pycnactis Ryder, 1926 Holophragma Lindstrom, 1896 Desmophyllum Wedekind, 1927 Cyathactis Soshkina, 1955 Ryderophyllum Tcherepnina, 1965 Neocystiphyllum Wedekind, 1927, may also belong here. Foo (little (is-known of. the- structure :of Lamprophyllum Wedekind, 1927, to warrant placing it, at present, in this family. Genera otherwise qualifying for assignment to the Lykophyllidae are doubtless synonyms, such as Mesactis Ryder, 1926, and Lykophyllum Wedekind, 1927. Genus RYDEROPHYLLUM Tcherepnina, 1965 1965. Ryderophyllum Tcherepnina, p. 31, pl. 2, figs. la, 1b. Type - species. _- kasandiensis Tcherepnina; by author designation. Ludlovian, Altai Mountains, Siberia. Diagnosis.-Small and medium-sized ceratoid to tro- choid rugose corals with numerous long, usually thin, smooth major septa; no septal stereozone or fossula. Dissepimentarium wide, with several columns of small to medium globose dissepiments. Tabularium wide, with close-spaced, mostly incomplete, axially flattened tabulae. Remarks.-Ryderophyllum is not known to pass through a Pycnactis-like neanic growth sequence with septa thickened and laterally in contact, differing thus from Phaulactis, in which thickened septa may persist in cardinal quadrants well into mature growth (Ryder, 1926; Smith, 1980; Minato, 1961). Ryderophyllum may be a junior synonym of Cyathactis Soshkina, 1955. An anguloconcentric pattern of chevron dissepiments develops in Cyathactis tenuiseptatus Soshkina and lonsdaleioid dissepiments in C. socialis Soshkina, neither feature appearing in the type species (C. typus Soshkina) or in Ryderophyllum. Other lycophyllids assigned to Cyathactis reveal, in longitudinal section, a depressed zone at the outer tabularium margin; among these are Cyathactis pegramense (Foerste) and Cyathactis catilla (Sutherland). As in the genus Phaulactis, species of Ryderophyllum may have adult major septa thickened axially within the tabularium but attenuated in the dissepimentarium. The type species, kasandiensis, was reported by Tcherepnina (1965) to occur in beds of Ludlovian age at Kasandi, Altai Mountains, U.S.S.R. Great Basin re- presentatives are in coral zone B, which is early Wenlockian in age. The probably related Phaulactis of Gotland is abundant in the Wenlock (Wedekind, 1927; Minato, 1961) and ranges elsewhere from Llandoverian to upper Ludlovian (Smith, 1980; Bulvanker, 1952; Hill, 1956; Oliver, 1962a). Cyathactis is known in beds of Middle and Late Silurian age. Ryderophyllum ubehebensis, n. sp. Plate 6, figures 1-7 Type material. USNM 159396; paratypes USNM 159394, 159395, 159397, 159398, 159399. Hidden Valley Dolomite, Ubehebe district, California; locality M1094. Diagnosis.-Medium-sized ceratoid_ and trochoid Ryderophyllum with wide tabularium in which some of the axially flattened tabulae are nearly complete. Peri- pheral dissepiments steeply inclined. Calice deep and acutely conical. External features. -Available material is silicified and weathered such that external details are poorly shown. Exteriors appear to have been rather even and smooth, with few rugae. Rejuvenescence rims may be developed in mature growth stages. Longitudinal grooves of weathered specimens interseptal, not true septal grooves. Outer wall probably very thin and without a septal stereozone. Transverse sections.-Long major septa numbering about 46 in larger adult individuals; some septa extend- ing to axis in early ephebic stage. Minor septa long, commonly more than half the length of major septa. In ephebic stages, all septa usually rather uniformly thin- ned, unbroken, and only slightly wavy. - Close-set dissepiment traces of outer zone making the angulo- concentric chevron pattern of this genus and some species of Phaulactis. Neanic stages well enough preserved for sectioning are not available. The possibility that this species passes through a Pycnactis stage with thickened septa cannot be entirely eliminated. One mature specimen shows thickening of major septa within the tabularium only. Longitudinal sections.-Eight or 10 dissepiment columns on each side; most of these steeply inclined axially, including those near the periphery. _ Wide tabularium sharply set off from dissepimentarium in most places; some tabulae nearly complete. Wider tabulae nearly straight or with slight axial sag, bending down peripherally at the depression which lies between the tabularium and dissepimentarium. In parts of the tabularium wide tabellae combined with the more continuous tabulae. Comparison with related forms.-Ryderophyllum ubehebensis has a slightly narrower tabularium than kasandiensis, the type species. Cyathactis of the Gazelle Formation in the Klamath Mountains has a narrower tabularium and a crowded chevron dissepiment pattern not present in ubehebensis. Cyathactis pegramense of the Brownsport Formation in Tennessee differs in having laterally depressed tabulae as in the Gazelle species. The northern British Columbia Ptycophyllum sp. (Norford, 1962, pl. XIV, figs. 5-8), from the Silurian Sandpile Group, is probably very similar to ubehebensis. Material SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY 45 showing early growth stages is needed to compare R. ubehebensis with Phaulactis, the adult stages of which commonly resemble this new species. Occurrence.-Hidden Valley Dolomite; Silurian coral zone B. Ubehebe Peak area, northern Panamint Range, locality M1094. Andy Hills, northern Panamint Range, localities M1095, M1109. Funeral Mountains, locality M1098. Study material of this species consists of 14 coralla (M1094), five coralla (M1095), one corallum (M1109), and two coralla (M1098). Genus PYCNACTIS Ryder, 1926 1820. Hyppurites mitratus Schlotheim, p. 352 (in part). 1850-54. Aulacophyllum mitratum. Edwards and Haime, p. 280, pl. Ixvi, figs. 1, la, 1b. 1926. Pycnactis Ryder, p. 386-390; pl. ix, figs. 1-8. 1927. Aulacophyllum angelini Wedekind, pl. 24, figs. 3-5. 1937. Pycnactis Ryder. Butler, p. 93-95. 1940. Pycnactis Ryder. Lang, Smith and Thomas, p. 112. 1956. Pycnactis Ryder. Hill, p. F272, fig. 185.5. Type species. mitratus Schlotheim, 1820; by original designation (Ryder, 1926). Silurian, Gotland, Sweden. Diagnosis.-Solitary trochoid rugose corals with long thickened major septa laterally in contact and pinnately arranged; cardinal septum long, minor septa very short or suppressed. Tabulae and dissepiments suppressed. Remarks.-The ontogeny of Pycnactis mitratus was elucidated by Ryder (1926, p. 389), and the supposed genetic relationships of Pycnactis, Mesactis, and Phaulac- tis were further examined by Butler (1987). Phaulactis and other lykophyllids are believed to pass through early growth stages, such as Pycnactis (Minato, 1961); however, the Pycnactis stages are not known in Ryderophyllum and Cyathactis. Occurrence.-According to Ryder (1926, p. 389), the Gotland and British Pycnactis mitratus is from beds of Wenlockian age. Hede (in Regnéll and Hede, 1960, p. 70, 73, 77) listed this species from the Slite Group, which is higher Wenlockian. Great Basin Pycnactis occurs in coral zone B, considered early Wenlockian. Pycnactis sp. k Plate 6, figures 10-12 Silicified corals assigned to Pycnactis occur in association with Ryderophyllum ubehebensis. Because of their large size, they are probably not immature growth stages of this lykophyllid. From 36 to 48 septa, arranged pinnately with reference to cardinal plane. Minor septa not distinguishable in transverse section. Epitheca or outer wall absent in avail- able specimens, which externally show pinnate pattern of thickened septa. Occurrence.-Hidden Valley Dolomite; early Middle Silurian, coral zone B. Andy Hills, northern Panamint 504-634 O - 73 - 4 Range, locality M1109. Funeral Mountains, locality M1098. Study material consists of two coralla (M1109) and one corallum (M1098). Family CYSTIPHYLLIDAE Edwards and Haime,1850 Reference form.-Cystiphyllum siluriense Lonsdale,® 1839; Silurian, Wenlock Limestone, Dudley, England. Remarks.-Silurian cystiphylloid corals include species which reveal trabecular septal spines in transverse thin section; some, however, lack these spines interally. In some individuals septal traces have been observed only on the calice floor, where they show as weak, radiating, spiny septal ridges or striations 1902). Edwards and Haime's (1850-54, p. 298, pl. 72, fig. 1a) description and figure of the trochoid Cystiphyllum siluriense suggest that the type species has faint calicular septal ridges. However, the internal features of siluriense from the type area remain to be elucidated. Cystiphyllum cylindricum Lonsdale (Lang and Smith, 1927, p. 477, pl. 36, figs. 1-5; Hill, 1956, fig. 214.la, 1b), another British Silurian species, shows numerous trabecular septal spines more or less radially alined. Wedekind's figures of Gotland corals referred to Lonsdale's C. siluriense also reveal abundant short. trabecular . septal | spines. In. the Gotland Holmophyllum _ Wedekind and Hedstromophyllum Wedekind the trabecular spines are much longer and heavier than in the genus Cystiphyllum. Cystiphylloids thus far studied by the writer from the Silurian of western North America reveal few or no tra- becular spines. However, Cystiphyllum cf. C. tubiforme Poulson figured by Norford (1962, pl. 13, figs. 8-11) from the Silurian of British Columbia clearly shows such features. Cystiphyllum? henry housense Sutherland (1965, p. 24, pls. 13-16) shows sporadic trabecular spines in some individuals, but, otherwise, it may be generically distinct from Cystiphyllum. Cystiphylloids of the Devonian undoubtedly represent many homoeomorphic lineages not closely related to the Silurian Cystiphyllum and are placed in other families, such as the Cystiphylloidae and Digonophyllidae, the last with strong septal crests and discrete septa. Microplasma Dybowski of the western North American Silurian shows trabecular septal spines only in the wall and is, with reservation, assigned to this family. Forms here provisionally assigned to the family Cysti- phyllidae are as follows: Cystiphyllum Lonsdale," 1839 Hedstromophyllum Wedekind, 1927 Holmophyllum Wedekind, 1927 Group of Cystiphyllum? henryhousensis Sutherland, 1965 (?)Microplasma Dybowski, 1873 In Murchison (1839, p. 675-699, 5, pls.). "In Murchison (1839, p. 675-699, 5 pls.). 46 Genus MICROPLASMA Dybowski, 1873 Type species.-Microplasma gotlandicum Dybowski; by subsequent designation, Wedekind (1927, p. 64). Silur- ian, Gotland, Sweden. Diagnosis.-Slender cylindrical corallites; in longitud- inal thin section, interior occupied by two to four columns of large globose dissepiments or tabellae which are not readily distinguishable. Wall a stereozone in which septal trabeculae are embedded and from which very short septal ridges project inward. No trabecular septal spines on dis- sepiments or tabellae as in Cystiphyllum. Remarks.-Microplasma may be a fasciculate colonial genus, but ordinarily only isolated corallites are found. Microplasma? sp. R Plate 7, figures 10,11 Small and presumably solitary cystiphylloid corals oc- curring in the Silurian Roberts Mountains Formation of the type section are known only from fragmentary material referred provisionally to this genus. A transverse thin section 11 mm in diameter shows an outer ring of large lonsdaleioid dissepimental traces with two larger tabellar traces occupying the interior. In longitudinal thin section, all these chambers are defined by axially inclined, usually continuous tabulae or tabellae, disposed in such manner that the term "dissepi- ment'' may not be entirely appropriate. The wall is laminar stereome in which are embedded septal trabeculae, spaced about four per millimeter; these trabeculae support very short abruptly tapering septa which cannot be distinguished as major and minor. Occurrence.-Top of unit 2, just above limestones with abundant Conchidium-like pentameroid brachiopods, and at base of Silurian coral zone C, type section of Roberts Mountains Formation. Ridge between south and middle forks of Pete Hanson Creek, locality M1089. Family GONIOPHYLLIDAE Dybowski, 1873 Representative genus and species. py- ramidalis (Hisinger); Silurian, Gotland, Sweden. These extraordinary operculate rugose corals have a worldwide distribution in the Silurian and Devonian (Lindstrom, 1883). Most of the American forms initially assigned to Calceola have, on careful study, been recognized as the genus Rhizophyllum, which is largely Silurian but ranges upward into strata of Devonian age. Oliver (1964) restudied several of the American species and described new species of Rhizophyllum. The following genera are included in this family: Goniophyllum Edwards and Haime, 1850 Rhizophyllum Lindstrom, 1866 Teratophyllum Lang, Smith, and Thomas, 1940 Rhytidophyllum Lindstrom, 1883 Calceola Lamarck, 1799 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Of these genera, only Rhizophyllum has been found in the Great Basin and in western North America generally. Genus RHIZOPHYLLUM Lindstrom, 1866 1866. Rhizophyllum Lindstrom, p. 287. 1940. Rhizophyllum Lindstrim. Hill, p. $94. 1956. - Rhizophyllum Lindstrom. Hill, p. F314. 1964. Rhizophyllum Lindstrim. Oliver, p. D149-D158. Type species. -Calceola gotlandica Roemer, 1856; by monotypy. Silurian, Gotland, Sweden. Diagnosis.-Calceoloid rugose corals with operculum; interior occupied by cystiphylloid dissepiments and tabellae. Septa short and limited to flat side; counter septum commonly longer and more prominent. Radiciform processes occasionally present. Remarks.-Calceola differs in having a stereoplasm- filled interior and is, insofar as known, confined to Devonian rocks. Rhizophyllum sp. D, Oliver Plate 7, figures 12-14 1930. - Calceola sandalina Lamarck. Staulfer, p. 107, pl. 12, figs. 2, 3. 1964. - Rhizophyllum sp. D, Oliver, p. D155. This somewhat compressed species has its greatest dia- meter of about 35 mm at the calice rim and a cardinal- counter diameter of about 15 mm; the length is about 43 mm. The flat thick septate wall projects as a tongue 16 mm above the calice rim; this wall is notched medially to ac- comodate the counter septum. The position of the medial counter septum is evident on the flat exterior where it lacks the strong longitudinal fold of R. gotlandicum; there are no indications of radiciform processes. In mature transverse section this form resembles RAhizo- phyllum sp. A of Oliver (1964, p. D15S, fig. 158.1) in general features of size, proportions, and distribution of dissepiments and tabellae. This southeastern Alaska species comes from the higher Silurian of Kosciusko Island. Rhizophyllum sp. cf. R. enorme of Oliver from Late Silurian coral facies of the Roberts Mountains Formation at Coal Canyon, Simpson Park Mountains, Nev., appears to be a somewhat less compressed form than sp. D. Occurrence.-Middle part of the Vaughn Gulch Lime- stone about 800 feet above its base. Mazourka Canyon, northern Inyo Mountains, Calif., near locality M1092. The float specimen is probably from a horizon near the bottom of coral zone E. Family KYPHOPHYLLIDAE Wedekind, 1927 Reference - genus - and _ species. -Kyphophyllum lindstromi Wedekind. Silurian, Gotland, Sweden. The Kyphophyllidae are mostly colonial, phaceloid and cerioid forms among which the fasciculate species with long subcylindrical corallites predominate.Long lamellar septa are characteristic, with one to several dissepiment SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY 47 columns, the outer of which are lonsdaleioid in some genera. Tabulae are fairly wide and arched in some of the genera, and in a few a flaring calice rim is known. Genera provisionally included in this family are as follows: Kyphophyllum Wedekind, 1927 Strombodes Schweigger, 1819 Petrozium Smith, 1930 Entelophyllum Wedekind, 1927 Entelophylloides Rukhin, 1938 (as a subgenus) Entelophylloides (Prohexagonaria), n. subgen. Neomphyma Soshkina, 1937 (?)Tonkinaria, n. gen. Genus KYPHOPHYLLUM Wedekind, 1927 1927. Kyphophyllum Wedekind, p. 18-22. 1940. Cyphophyllum, Lang, Smith, and Thomas, p. 47. 1956. Kyphophyllum Wedekind. Hill, p. F276. Type species. lindstromi Wedekind (1927, explanation pl. 2); by original desegnation. Silurian, Gotland, Sweden. Diagnosis.-Phaceloid and solitary rugose corals with elongate subcylindrical corallites; three or more columns of dissepiments, the outer of which are in part lonsdaleioid; moderately wide, partly continuous tabulae, and a rather narrow septal stereozone. Remarks. Smith, and Thomas (1940, p. 47) and Smith (1945, p. 57) noted the similarity of internal struct- ure between Wedekind's Kyphophyllum lindstromi and the phaceloid Strombodes stellaris, type species of Strombodes Schweigger, 1819. That the two are actually congeneric is somewhat doubtful at present, and sup- pression of Kyphophyllum as a synonym on this basis should await comparison of adequate Gotland topotype material. In Kyphophyllum the septa are long, major septa approaching the axis, and are peripherally discontinuous as septal crests in the lonsdaleioid areas. The tabulae are typically arched but may be flat or even sagging. Entelophyllum differs by lacking the lonsdaleioid dis- sepiments, having a narrower septal stereozone, and having fairly numerous lateral radiciform connections between - corallites. Pilophyllum _ Wedekind, with lonsdaleioid marginarium, has a heavier septal stereo- zone and a much wider tabularium comprising many overlapping tabellae and few complete tabulae. Wedekind's type species K. lindstromi is reported from a locality north of Stenkyrke huk, Gotland, in the "untere Mergel"; this map occurrence suggests Visby Marl, pro- bably the lower part, and therefore late Llandoverian age. Undescribed Kyphophyllum from the Gazelle Formation, Klamath Mountains, Calif., occurs in strata believed to be high in that formation and is therefore either Ludlovian or very early Devonian. The Great Basin occurrences are also high in the Silurian (Ludlovian). -.. \. phyllum nevadensis, n. sp. Plate 13, figures 1-4 Type material. -Holotype USNM 159425; Upper Silurian, Ikes Canyon, Toquima Range, Nev. Diagnosis. -Kyphophyllum forming large phaceloid or bushy colonies; corallites with narrow stereozone, medium-wide closely spaced tabulae, and irregular, wide peripheral segments of lonsdaleioid dissepiments. Transverse sections. -About 22 major septa, most of which reach the axis, where they may be somewhat twisted; septa smooth and straight to wavy, in places having sharp zigzag carinae. Minor septa nonuniform and discontinuous, varying from short projections at the stereozone to broken septa more than half as long as major septa. All septa discontinuous in the lonsdaleioid areas. Dissepiment trace pattern very irregular. Septal stereozone narrow. Longitudinal sections. -Tabulae closely spaced, partly complete with downward sag and averaging about one- quarter width of corallite. Dissepimentarium with three to five columns of nonuniform dissepiments ranging from small and globose to large and elongate, the outer ones being partly lonsdaleioid; most dissepiments steeply inclined, the inner ones near vertical. No discrete axial structure. Reproductive offsets.-Probably develop laterally from calice rim. Microstructure. not clearly shown in walls and stereozone of well-preserved specimens. Comparison with related forms.-A similar un- described Kyphophyllum from Late Silurian or Early Devonian strata of the Gazelle area, northeast Klamath Mountains, Calif., has a narrower tabularium and more extensive development of large lonsdaleioid dissepiments; some of the Klamath specimens have a wider stereozone. Kyphophyllum lindstrimi of the Gotland Silurian shows a narrower dissepimentarium, and its wider tabulae are arched with median sag and marginal depression not present in either nevadensis or the Klamath species. The Gotland form is reported to be a solitary coral. Occurrence.-In lower part of McMonnigal Limestone of Kay and Crawford (1964); coral zone E. Northwest side of Copper Mountain, Ikes Canyon, Toquima Range, locality M1114. Study material consists of one large, nearly complete corallum and fragments of other coralla. Genus PETROZIUM Smith, 1930 Type species. -Petrozium dewari Smith (1980, p. 307, pl. XXVI, figs. 20-28) by original designation. Lower Silurian, Valentian, Shropshire, England. Diagnosis.-Phaceloid rugose corals having long slender - cylindrical - corallites without connecting processes. Long axially thin major septa, some of which meet at the center, where they may be involved in an incipient axial structure. Dissepiments in several 48 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN columns, small, globose, steeply inclined toward axis. Tabularium wide, comprising arched tabellae mostly in- clined toward the periphery. Septal stereoitone thin or absent. Remarks.-True carinae, though mentioned in Smith's generic diagnosis, are not present in the American species; however, the septa may possess zigzag gleatures. An Alaskan species of Petrozium from Kuiu Island, south- eastern Alaska, has a discrete axial structure chinforced by stereoplasm to form a small bladelike columella. Petrozium probably ranges through most of the Silurian System; the type species is‘ Valentian (Llandoverian) Early Silurian. P. meallisteri, n. sp., of the Great Basin occurs in coral zone B, which is Wenlockian. An undescribed Petrozium in the Gazelle Formation of the Klamath Mountains in California is high Wenlockian or Ludlovian. As Petrozium is a rather specialized genus, such a long range is surprising. Petrozium mcallisteri, n. sp. Plate 9, figures 6-10 Type material. -Holotype USNM 159411. _ Diagnosis. -Petrozium with major septa slightly thickened peripherally, tapering to very thin where meeting axially. Septa have minute zigzag feyures. Transverse sections. -About 20 major septa, some of which reach the axis; septa mostly wavy and‘commonly zigzag peripherally. Major septa slightly thickened per- ipherally, attenuated axially. Minor septa rather long, some exceeding half the length of major septa. Septal stereozone weakly developed or absent. Symmqtry entirely radial; no suggestion of a fossula. Longitudinal sections-Tabularium about half the width of corallum, comprising arched tabellae without complete tabulae. Tips of major septa intersect, suggesting an incipient axial structure, but no development of true columella. | Comparison - with - related forms.—i’etrozium meallisteri has fewer septa than dewari, the tfipe species, but it is otherwise very similar, especially in longitudinal section. An undescribed Petrozium in the Silurian Gazelle Formation of the Klamath Mountains has more even, less tapering septa without zigzag features; some cprallites of the Gazelle species have a suggestion of a fossula not re- cognized in meallisteri. Occurrence.-Lower part of the Hidden Valley Dolomite; 1% miles north of Ubehebe Peak, Northern Panamint Range, locality M1111. The large silicified head of the coral here described was collected as float below the main in situ locality (M1094), but it is believed to have come from the bed of silicified corals which is the type occurrence of Great Basin coral zone B. Study material consists of a single large corallum. | Genus ENTELOPHYLLUM Wedekind, 1927 1927. Entelophyllum Wedekind, p. 22-24; pl. 2, figs. 11, 12; pl. 7, figs. 7-10; pl. 29, figs. 18-51. 1927. Xylodes Lang and Smith, p. 461, 462, figs. 18, 14. 1929. Xylodes Lang and Smith. Smith and Tremberth, p. 862-867; pl. 7, figs. 1-6; pl. 8, figs. 2-4. 1940 Entelophyllum Wedekind. Lang, Smith, and Thomas, p. 57-58. 1940. Entelophyllum Wedekind. Hill, p. 411. 1956. Entelophyllum. Duncan, pl. 23, figs. 5¢, 5d. 1956. Entelophyllum Wedekind. Hill, p. F275, fig. 187,2a-c. 1962. Entelophyllum Wedekind. Stumm, p. 2, 3. 1962a. - Entelophyllum Wedekind. Oliver, p. 15. 1964. Entelophyllum Wedekind. Stumm, p. $2. Type species. -Madreporites articulatus Wahlenberg = Entelophyllum articulatum (Wahlenberg). By sub- sequent designation, Lang, Smith, and Thomas (1940, p. 57, 140). Silurian, Gotland, Sweden. According to Smith and Tremberth (1929, p. 366), this species occurs at several localities in strata of Wenlockian and Ludlovian age on Gotland; it is recorded in England from Wenlock Limestone. Diagnosis.-Phaceloid or solitary rugose corals with elongate subcylindrical mature corallites. Major septa thin or slightly thickened only near outer wall, ap- proaching or slightly withdrawn from axis. Tabularium wide, typically with closely spaced flat tabulae and tabellae and a narrow peripheral, proximally depressed zone bordering the dissepimentarium. Dissepimentarium having from a few to many columns of small steeply in- clined globose dissepiments. Outer wall thin and without stereozone. No fossula or indication of bilateral symmetry in mature stages. Septa slightly to moderately wavy, but well-developed angle-carinae not present in typical form. Lateral attachment outgrowths from wall characteristic of some species. Five or six reproductive offsets developed marginal to the calice. Remarks.-Not all species placed in Entelophyllum have the strongly depressed peripheral zone of the tab- ularium shown by the type species. The English Wenlock representatives of E. pseudodianthus (Weissermel) have zigzag, thickened, highly carinate septa and less el- ongated cylindrical corallites (Smith and Tremberth, 1929, p. 361-362; Lang and Smith, 1927, p. 475, text fig. 15). Disphyllum of the Middle Devonian is similar to Entelophyllum. However, it is usually very slender, lacks the numerous coarse or thick attachment outgrowths of some species of Entelophyllum, has more even septa without carinae, and commonly has a somewhat wider tabularium. The transverse sections of Disphyllum show a more uniformly even concentric distribution of axially concave dissepiment traces. Some forms of Entelophyllum have several reproductive offsets marginal to the calice, a condition not known in Disphyllum. 2 «« SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY Entelophyllum eurekaensis, n. sp. Plate 10, figures 1, 2, 14, 15 Type material. -Holotype USNM 159412; paratype USNM 159419. Diagnosis.-Subcylindrical to ceratoid Entelophyllum with wide tabularium and closely spaced, straight, nearly continuous tabulae and flat peripheral tabellae, per- ipheral zone of tabularium proximally depressed as in typical Entelophyllum. Septa slightly thickened, with longer major septa approaching axis. Small- to medium- sized dissepiments appearing in transverse sections as axially concave and chevron traces. External features.-Known only from isolated pieces but assumed to be phaceloid, like the related species E. engelmanni of the same interval in the Lone Mountain Dolomite. Available specimens ceratoid rather than sub- cylindrical. Transverse sections. -About 30 major septa, most of which are withdrawn, but a few approach the axis; minor septa from short wedgelike stumps to about half the length of major septa. Septa not as thin as in most species of Entelophyllum and only slightly wavy. No carinae re- cognized. Dissepiments include herringbone and chevron traces as well as those that are concentric and axially con- cave. Septa wedge out markedly at outer wall, but no thickened stereozone; epitheca rather thin. Longitudinal sections. -Tabularium width nearly two- thirds the diameter. Tabulae, in part, nearly continuous, axially and periaxially flat, peripherally depressed. Flat peripheral tabellae also present. Small to fairly large, steeply inclined dissepiments. Comparison with related forms.-This species has a wider tabularium than engelmannit of the upper Lone Mountain Dolomite; the tabulae are medially flat with peripheral - sag, conditions less characteristic of engelmanni. Elongate cylindrical corallites with lateral growths and the bushy growth habit of engelmannt are unknown in eurekaensis. Occurrence.-Late Silurian, upper part of the Lone Mountain Dolomite; upper Lone Mountain-Laketown biofacies containing Howellella pauciplicata. Southern Fish Creek Range, Nev. locality M1113; associated with a silicified brachiopod assemblage including Howellella pauciplicata, Protathyris hesperalis, and Camerotoechia pahranagatensis. Study material of this species consists of 22 disassociated corallites. Entelophyllum engelmanni, n. sp. Plate 10, figures 5-13 Type material. -Holotype USNM 159413; paratypes USNM 159414, 159415, 159416, 159417; figured specimen USNM 159418. Diagnosis.-Phaceloid Entelophyllum forming large 49 bushy colonies of nearly straight subcylindrical corallites joined by lateral outgrowths. Tabularium wide, tabulae mostly complete and subparallel, not always with per- ipheral sag as in typical Entelophyllum; some tabulae with axial and periaxial sag or with slight distal arching. Tabellae not common. Major septa withdrawn from axis, slightly wavy, and with no carinae. Minor septa short, us- ually less than half the length of major septa. Septa thin internally but with wedge thickening at wall. No stereo- zone. External features. mature corallites large for this genus, with well defined septal grooves crossed by annular incremental striations but without coarse annular folds or rugae. Some corallites with thick irregular lateral attachment outgrowths along one side with vertical distribution. Transverse sections.-About 28 major septa, thin in- ternally and slightly withdrawn from the axis. Minor septa short, less than half the length of major septa. All septa wedges thickening at very thin outer wall. Septa slightly wavy and lacking carinae. Dissepiments not numerous, rather irregular as chevrons, forks, and simple traces which are either almost straight or slightly concave axially. Longitudinal sections. wide, about two- thirds of the diameter. Tabulae mostly complete, varying from straight or slightly arched axially and periaxially with or without peripheral depression to those with axial- periaxial sag and no peripheral depression. Dissepiments globose in one to three columns, steep and of small, medium, and large size. A few broad flat tabellae peri- pherally. Comparison with related forms.-Entelophyllum engelmanni differs from eurekaensis in the unevenness of its tabulae, which commonly lack the peripheral de- pression; its very elongate cylindrical corallites have lateral processes not observed in eurekaensis. Occurrence.-Late Silurian, upper part of the Lone Mountain Dolomite; upper Lone Mountain-Laketown biofacies. Southern Mahogany Hills, Nev. locality M1112. Southern Fish Creek Range, Nev., locality M1087. A similar form occurs in Silurian dolomite of the Ruby Mountains, Nev. (pl. 15, figs. 12-16). Study material of this species consists of several hundred corallites from numerous coralla (locs. M1087, M1112). Genus ENTELOPHYLLOIDES Rukhin, 1938 (as subgenus of ENTELOPHYLLUM) 1988. Entelophyllum (Entelophylloides) inequalum (Hall), Rukhin, p. 25. Type species. -Columnaria inequalis Hall (in part), 1852, p. 323, pl. 72, figs. 3, 4; by author designation. Silurian, Cobleskill Limestone, New York. Diagnosis.-Cerioid rugose corals with long, even septa, several columns of small and medium dis- 50 SILURIAN RUGOSE CORAL? OF THE CENTRAL AND SOUTHWEST GREAT BASIN sepiments, and tabulae of medium width. Lc‘msdaleioid dissepiments inconspicuous or lacking. No axial struc- ture. | Remarks.-Carinae were not observed in transverse thin sections of the type species, but longitudinal (gin sections reveal numerous delicate spinose bars or spurs extending laterally from the tabularium septal extensions. In the type species the number of major septa, being fibout 12, is small for the compound Rugosa. Some major Tepta reach the axis; minor septa are only a little shorter. The outer dissepiments are more irregular and nonuniform than the more concentric inner ones and may be sporadically sub- lonsdaleioid in the largest corallites. Entelophylloides, erected by Rukhin as a subgenus under Entelophyllum, is here considered an independent genus. The genus is Late Silurian.Specimens collected by Jean Berdan from the Silurian Cobleskill Limestone in the vicinity of Shutters Corners, Schoharie quadrangle, New York, are considered topotype material of Hall's ine- qualis. Similar corals from the Keyser Limestone of the Evitts Creek area, Maryland, collected by Jean Berdan and Helen Duncan, appear to be a distinct species with thicker septa and fewer septal spines within the tabularium. Subgenus ENTELOPHYLLOIDES, sensu stricto Type species.--Entelophylloides (Entelophylloides) inequalis (Hall). This subgenus has the characters of the genus Entelo- phylloides in the strict sense. Its members include species with small corallites, a small average number of major septa (about 12), straight unarched tabulae, and numerous lateral spines or spurs on major septa within the tabularium. Subgenus PROHEXAGONARIA, new subgenus Type species.-Entelophylloides (Prohexagonaria) oc- cidentalis, n. sp.; here designated. Silurian, bottom of unit 3 of the Roberts Mountains Formation; Roberts Creek Mountain, Nev. Diagnosis.-Cerioid rugose corals with numerous long thin septa, some reaching the axis; minor septa three- fourths the length of major septa. Tabularium less than one-third the corallite diameter; tabulae close spaced, some complete and straight, some arched as tabellae. Dis- sepimentarium wide, with eight or more columns of small- and medium-sized dissepiments which are nearly flat peripherally. Elbow or zigzag carinae inconspicuous. Septa with no lateral spines. > Remarks.-This subgenus has about 18 major septa, averaging 12 in typical Entelophylloides. Another significant distinction is absence of septal spines or spurs, which show well in longitudinal thin sections of the type species. Hexagonaria of the Devonian has more evenly and uniformly globose dissepiments, a more uniform pattern of concentric dissepimental traces in transverse section, and a broader tabularium. The typical Hexagonaria is characterized by yardarm carinae not present in Entelo- phylloides. The septal spines or spurs of the latter are absent in Hexagonaria.. Prohexagonaria resembles the Silurian cerioid Tenu:- phyllum Soshkina; the latter has an arched axial develop- ment more like Petrozium. Somewhat closer morphologically are Silurian cerioid forms heretofore classified as cerioid "Xylodes" or cerioid Entelophyllum. Undescribed cerioid Silurian Rugosa of the Gazelle Formation, Klamath Mountains, Calif., superfically resemble Entelophylloides, sensu stricto, but the tabularium is narrower, tabulae are weakly developed, the septa are thickened toward the wall, and larger lonsdaleioid dissepiments are sporadically developed. Entelophylloides (Prohexagonaria) occidentalis, n. sp. Plate 9, figures 1-4 1940. Strombodes. Merriam, p. 12, 92. 1963b. Strombodes. Merriam, p. 38. Type material.-Holotype, USNM 159410; Silurian, unit 3 of the Roberts Mountains Formation. Roberts Creek Mountain, Nev. Diagnosis.-Prohexagonaria with numerous, some- what wavy, unthickened septa. In transverse thin section, the dissepiment pattern includes many peripheral angulo- concentric and nearly straight traces. Tabulae close spaced and arched or flat. Corllite wall fairly straight. External features.-Occurs in compact cerioid heads exceeding a diameter of 10 inches. Transverse sections.-Major septa 18-20, unthickened throughout, with waviness increasing peripherally. Some incipient angulation carinae developed, but none showing in depth as true carinae in longitudinal thin sections. Pattern of dissepiment traces mostly concentric, but peripherally these traces changing to irregularly anguloconcentric or nearly straight with increasing septal waviness. A slight tendency to develop scattered small sublonsdaleioid dissepiments near walls. Longitudinal _ sections.-Mostly _ small _ globose dissepiments developed in eight or more columns. Combinations of close-spaced complete tabulae and tabellae which are more commonly uparched than flat in the tabularium. Reproductive offsets.-Small interstitial reproductive offsets developed from the calice margin (seen in transverse sections). Comparison with related forms. -Entelophylloides (Prohexagonaria) sp. from Visby, Gotland, figured by SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY S1 Smith and Tremberth (1929, pl. 8,fig. 1) as "Xylodes sp." resembles occidentalis in transverse section. (See pl. 9, fig. 5.) The cerioid "Acervularia mixta" Lindstrom (1882b) from reported Silurian rocks of the central Siberian uplands differs in having a zigzag wall, and in longitudinal section it shows an axial structure more like that of Petrozium. Other than this species, American Late Silurian forms assigned to Entelophylloides for the most part have the subgeneric features of inequalis (Hall), as outlined above. A species from the New Jersey Decker Ferry Formation assigned by Weller (1903, p. 219, pl. 17, figs. 12, 13) to Hall's species is similar to occidentallis in transverse section, but, as illustrated in longitudinal section, it lacks straight or complete tabulae. Entelophylloides from the Keyser Limestone of Maryland assigned by Swartz (1918, pl. 20, figs. 1-4) to Hall's inequalis presumably falls in the subgenus Entelo- phylloides, sensu stricto; this species differs from occidentalis in its peripherally wedge-thickened septa and in its scattered large peripheral dissepiments. Occurrence.-Lower beds of unit 3 in the Roberts Mountains Formation; Middle Silurian coral zone C. Northwest side of Roberts Creek Mountain, Nev., locality M1102. Study material consists of two large coralla and pieces of other coralla from same coral bed. Genus NEOMPHYMA Soshkina, 1937 1937. - Neomphyma Soshkina, p. 76, 98; pl. XV, figs. 8, 4. 1940. Neomphyma Soshkina. Lang, Smith, and Thomas, p. 88. 1956. Neomphyma Soshkina. Hill, p. F298, fig. 203.4a-b. Type species. -Neomphyma originata Soshkina, 1937; by original designation. Silurian, Petropavlovsky region, east slope Ural Mountains. Reported as "Upper Ludlow." Diagnosis.-Solitary and fasciculate rugose corals with slender cylindrical mature corallites having a narrow peripheral - stereozone, large irregular peripheral lonsdaleioid dissepiments, and a few thin nonuniform dis- continuous septa, which may extend to the axis. Tabularium usually narrow; tabulae very unevenly developed, either widely spaced or closely set. Remarks.-Some corallites show almost no septa ex- cept for short spinose projections from the stereozone. The type species is reported by Soshkina to occur in beds of upper Ludlovian age. Neomphyma crawfordi, n. sp., from the Toquima Range, Nev., is associated with Arachnophyllum and Cyathophylloides ferguson: in strata which probably represent Great Basin coral zone A of Early Silurian (Llandoverian) age. Neomphyma crawfordi, n. sp. Plate 13, figures 5-8 Type material. -Holotype USNM 159426. Diagnosis.-Phaceloid, cylindrical Neomphyma with a few very large and irregular lonsdaleioid dissepiments in mature stages. Septal lamellae smooth. Primary septa highly irregular, nonuniform and wavy, most not reaching axis, commonly few or lacking medially, but always appearing at wall as crests. Outer wall a moderately thick stereozone. Dissepiments near vertical; tabulae mostly narrow, widely spaced, and nearly flat. External features.-Bushy phaceloid colonies 8 or more inches in diameter comprising close-set cylindrical, fairly straight corallites. No connecting processes observed. Sur- face marked by septal grooves and not very pronounced transverse rugae. Numerous small offsets originate from parental calice, especially at outer wall; one calice may have as many as four of these marginal offsets. Transverse section. stages with about 16 smooth simple wavy major septa, most of which do not reach the axis; minor septa very short. In ephebic stages, with appearance of the large lonsdaleioid dissepiments, the major septa increasing to 20 or more but commonly suppressed medially, showing only as the peripheral crests in some cystiform individuals. Peripheral stereozone about */, or '4, the diameter of the ephebic corallite. With some individuals, major septa discontinuous, appearing as short radial crests. Longitudinal section. -Large, steeply inclined to verti- cal nonuniform dissepiments arranged in one or two columns and occupying most of the corallite width. Few tabulae, widely spaced, more or less straight, and usually narrow. Walls of contiguous corallites commonly coalescing. Reproductive offsets.-(See external features.) Microstructure.-Trabecular structure poorly defined in stereozone, inclined peripherally a few degrees from horizontal. Comparison - with - related forms.-Neomphyma originata Soshkina (1937, p. 98, pl. XV, figs. 3, 4) differs from crawford? in having longer, more continuous major septa and a more irregular pattern of dissepiments, as ob- served in longitudinal section. The Russian species is re- ported from beds of Ludlovian age in the Urals and may accordingly be considerably younger than crawfordi of coral zone A. Occurrence.-Lower Silurian, coral zone A; in the Masket Shale of Kay and Crawford (1964). Ikes Canyon, Toquima Range, Nev., locality M1088. In association with Arachnophyllum kayi, n. sp., and Cyathophylloides fergusoni, n. sp. Study material consists of one nearly com- plete corallum and pieces of other coralla. Genus TONKINARIA, new genus 1956. (?)Entelophyllum. Duncan, pl. 23, figs. 5a, 5b. Type species. -Tonkinaria simpsoni, n. gen., n. sp.; here designated. Silurian; unit 3 of the Roberts Moun- tains Formation. Diagnosis.-Solitary and loosely phaceloid rugose corals with flaring trumpet-shaped calice, ceratoid to tur-: binate corallites, and narrow tabularium. Wall a narrow 52 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN stereozone; septa thin, major septa reaching or slightly withdrawn from axis. Some dissepiments large, elongate, and steeply inclined. Multiplication by three or more peripheral calice offsets. Remarks. Entelophyllum, the new genus Ton- kinaria does not have a cylindrical growth habit. The tabularium also differs from that of typical Entelo- phyllum, which commonly has several columns of smal- ler dissepiments. The internal structure of Tonkinaria re- sembles that of Neomphyma Soshkina (19837, p. 98), which differs in its cylindrical shape and larger dissepiments. Tonkinaria simpsoni is associated at its type occur- rence with phaceloid Rugosa of comparable exterior growth form but is otherwise unrelated. Placed in the new genus Stylopleura, these externally similar colonial corals are nondissepimented and possess cylindrical mature corallites. Tonkinaria simpsoni, n. sp. Plate 7, figures 1-8 Type material. -Holotype USNM 159403; paratypes USNM 159402, 159404; figured specimen USNM 159405. Diagnosis.-Small - Tonkinaria with ceratoid or trochoid corallites and usually a flaring calice; reproduc- tive offsets developed at the calice rim. Attachment by talons. External features.-The calice deeply conical to very widely flaring with peripheral platform and central pit. Broadly flaring or reflected types with a thin rim to which reproductive offsets are attached; septa extending to rim as broad slightly rounded to nearly flat ribs separated by sharp grooves. Septal grooves not strongly defined externally. Transverse sections.-Septa thin, somewhat wavy, and numbering about 8; most extending more than half the radius, and some reaching the axis. Short minor septa commonly present. Septa thickened peripherally toward the narrow septal stereozone. Dissepimental traces rather irregularly concentric and axially concave to straight. Longitudinal sections.-Tabularium narrow, less than one-third of diameter. Tabulae poorly defined in avail- able specimens but, where shown, very narrow, irregular- ly concave distally, and rather closely spaced. Dissepi- ments in three or more columns, steeply inclined, many of them relatively large and elongate. Reproductive offsets. -Offsets characteristically growing laterally or vertically from the calice rim, as il- lustrated on plate 7, figures 1 and 2. Asexual progeny com- monly attached to successive parents, resulting in com- plex colonial growth (pl. 7, fig. 9). Occurrence. Silurian, coral zone D; unit 3 of the Roberts Mountains Formation. Roberts Creek Mountain, Nev., locality M1100. Ikes Canyon reference section, Toquima Range, Nev., locality M1103. Provisionally as- signed to Tonkinaria is the Hidden Valley specimen (pl. 7, fig. 9) from locality M1097, Funeral Mountains (Ryan quadrangle). Study material consists of 21 coralla (loc. M1100), one corallum (loc. M1103), and one compound corallum (loc. M1097). Family CHONOPHYLLIDAE Holmes, 1887 Reference - genus. _ Edwards - and Haime, 1850. These corals are commonly very rugate externally, be- cause of their numerous rejuvenescence flanges and cone- in-cone growth habit. They have been frequently con- fused with the platelike nondissepimented Mycophyllinae because of taxonomic complications involving the identity of the type species of Chonophyllum (Smith, 1945, p. 19). As interpreted at present, the Chonophyl- lidae include only solitary species with a strong dissepi- mentarium comprising medium and large elongate lonsdaleioid dissepiments; most of the septa are discon- tinuous. Tabulae are flat medially, and most are continuous. Only the two genera Chonophyllum Edwards and Haime, 1850, and Ketophyllum Wedekind, 1927, are with assurance included in this family. Genus CHONOPHYLLUM Edwards and Haime 1850 1826. Cyathophyllum plicatum Goldfuss, p. 59, pl. xviii, fig. 5. 1850. - Chonophyllum Edwards and Haime, pl. Ixix. 1851. Chonophyllum perfoliatum (Goldfuss manuscript). Edwards and Haime, p. 405. 1902. Chonophyllum pseudohelianthoides Sherzer. PoCta, pl. 109, figs. 3-6. 1926. Not Chonophyllum Lang, p. 428-434, pl. xxx, figs. 4-6. 1927. Not Chonophyllum Lang and Smith, p. 454. 1927. Not Chonophyllum patellatum Schlotheim. Wedekind, pl. 7, fig. 1. 1927. Not Chonophyllum planum Wedekind, pl. 7, figs. 2, 8. 1927. Omphyma flabellata Wedekind, p. 59; pl. 17, figs. 3, 4; pl. 18, figs. 10, 11. 1940. - Chonophyllum Edwards and Haime. Lang, Smith, and Thomas, p. 36. 1945. - Chonophyllum Edwards and Haime. Smith, p. 19; pl. 30, fig. 3. 1949. Chonophyllum Edwards and Haime. Stumm, p. 48 (in part); pl. 23, fig. 4, Pig. 3, not figs. 5, 6. 1956. Chonophyllum Edwards and Haime. Hill, p. F300; fig. 204.32, 3b. Type species.-Cyathophyllum perfoliatum Goldfuss; Edwards and Haime, 1850; by original designation. Silurian, Gotland. Cyathophyllum perfoliatum Goldfuss is C. plicacum Goldfuss (1826, p. 59; pl. xviii, fig. 5), not C. plicatum Goldfuss (1826, p. 54, pl. xv, fig. 12). Diagnosis. -Large solitary trochoid, ceratoid, and tur- binate rugose corals with poorly defined wall and rough, uneven outer surface showing distally repeated edges of superposed growth cones. Septa numerous, long, some- what thickened; some major septa reaching axis. Tabularium narrow (4-4 mature corallite diameter); dis- sepimentarium wide, with nonuniform large and small SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY dissepiments, most of which are elongate. Peripheral dis- sepiments nearly flat, commonly very elongate, and in part lonsdaleioid. Calice shallow with broad, commonly reflected rim and central pit. Remarks.-Identity of the Chonophyllum type species has long remained in doubt. According to Lang, Smith, and Thomas (1940, p. 36) and Smith (1945, p. 19), the species name perfoliatum was personally substituted by Goldfuss for the name plicatum on the label of the Gotland type specimen in question, the name plicatum having been used also by him for another coral under the genus Cyathophyllum (Edwards and Haime, 1851, p. 405). Usage of Chonophyllum perfoliatum as set forth by Ed- wards and Haime (1850, pl. Ixix; 1851, p. 405) is ac- cordingly adopted here. A transverse section of the type specimen of Chono- phyllum - perfoliatum (Goldfuss manuscript) in the Goldfuss collection at the University of Bonn was figured by Smith (1945, p. 19-20, pl. 30, fig. 3), but the longitudinal section of this species remains unknown, leaving some uncertainty about the status of Chono- phyllum. Hill (1956, p. F300) noted, however, that the longitudinal section of perfoliatum has not been figured, but that the transverse section illustrated by Smith (1945, pl. 30, fig. 3) is very similar to that of the Gotland Omphyma flabellata Wedekind (1927, pl. 17, figs. 3, 4), which is known and illustrated in vertical section. Longitudinal sections of the Great Basin Chonophyllum simpsoni are very much like the section of Wedekind's flabellata, which was erroneously placed by him in Omphyma. Chonophyllum is probably related to Ketophyllum Wedekind, 1927, but has a narrower tabularium and septa that are more dilated. Ketophyllum usually has large lonsdaleioid dissepiments; these are less common or less conspicuous in Chonophyllum but are strongly developed in certain of the Great Basin corals assigned provisionally to this genus. Chonophyllum as used here is distinct from the large turbinate to patelloid nondissepimented Silurian corals with which it has been confused and which are now cor- rectly placed in Mucophyllum or in Schlotheimo- phyllum. Chonophyllum is copiously dissepimented, has septa which are far less dilated and which form a wide stereozone in these two genera, and lacks the axial struc- ture of Schlotheimophyllum. Corals belonging in Chono- phyllum or Ketophyllum have in the past been er- roneously assigned to Omphyma, the type of which, as noted by Hill (1956, p. F300), is unknown. Occurrence.-The range of Chonophyllum in the Got- land Silurian is poorly known. Wedekind's (1927, pl. 17, figs. 3, 4) record of Chonophyllum flabellata at "Othem, Solklint'"' suggests the Slite Group of Wenlockian age. Smith (1945, p. 19) recorded an occurrence of C. perfoliatum at Kriiklingbo, Gotland, which may well be 53 from strata of the Klinteberg Limestone, which is con- sidered Ludlovian. Great Basin occurrences are in the higher part of the Silurian column and are doubtless Ludlovian. Chonophyllum simpsoni, n. sp. Plate 8, figures 1-4 Type material. USNM 159408; paratype USNM 159409. Diagnosis.-Large trochoid. to ceratoid Chono- phyllum with major septa reaching axis, irregular lons- daleioid peripheral dissepiments, and narrow tabularium with close-spaced undulant incomplete tabulae and mar- ginal tabellae. Inner dissepiments commonly angulo- concentric in transverse section. External features.-This form possibly ceratoid in later mature stages of growth. Uneven projecting rims of close- ly spaced superposed rejuvenescence growth cones typical of the genus. Transverse sections. -About 32 major septa; minor sep- ta generally more than half the length of major septa. Sep- ta slightly thickened, smooth, straight to slightly wavy, not extending to periphery as spines in lonsdaleioid parts. Indications of stereoplasmic thickening of axial ends of septa, but no discrete axial structure. Some inner dissepi- ment traces with anguloconcentric chevron pattern. Lons- daleioid pattern highly irregular, occupying most of dis- sepimentarium or narrow. Longitudinal sections.-Tabularium sharply set off from dissepimentarium. Undulant tabulae spaced three to seven per millimeter; all tabulae incomplete and com- bined marginally with tabellae. Most of the peripheral dis- sepiments very elongate and either nearly horizontal or in- clined axially at a low angle. Stereoplasmic thickenings on upper surfaces of dissepiments. Reproductive offsets. -Chonophyllum simpsoni pro- bably a solitary species, as none of the study specimens show offsets. Comparison with related forms.-Chonophyllum simpsoni has smoother, more even septa than appear in Smith's (1945, pl. 30, fig. 3) transverse figure of the type species, perfoliatum, which may also have broken septa and septal spines in the lonsdaleioid parts. C. flabellata (Wedekind) shows discontinuous septa in lonsdaleioid patches throughout the wide dissepimentarium; the longitudinal section of this form is, however, very similar to that of C. simpsoni, although the tabulae are more near- ly complete and less undulant in flabellata. C. pseudo- helianthoides Sherzer of Po'ta (1902, pl. 109, figs. 3-6) is similar but has less undulant tabulae and has lons- daleioid dissepiments throughout the wide dissepiment- arium. This Bohemian form is reported from Barrandian Stage F or f of the Koneprus, which is presumably Early Devonian. Occurrence.-Upper part of the Roberts Mountains 54 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Formation; Upper Silurian, coral zone E. Coal Canyon, northern Simpson Park Mountains, Nev., locality M1108. The study material from this locality consists of two in- complete mature coralla and unsectioned fragmentary specimens probably representing this species. Family ENDOPHYLLIDAE Torley, 1933 Reference forms. -Endophyllum bowerbanki Edwards and Haime and E. abditum Edwards and Haime, 1851; Devonian, Torquay, England. Cerioid and aphroid rugose corals with wide corallites, a broad marginarium with some large lonsdaleioid dis- sepiments, and a narrow to very wide tabularium com- prising closely spaced tabulae (Jones, 1929). No axial structure. Genera provisionally assigned to the Endophyllidae are as follows: Endophyllum Edwards and Haime, 1851 Yassia Jones, 1930 Australophyllum Stumm, 1949 Australophyllum (Toquimaphyllum), n. subgen. An undescribed cerioid genus similar to Toquima- phyllum in the Silurian Gazelle Formation of the Kla- math Mountains, Calif., also belongs in the Endophyl- lidae.Pilophyllum Wedekind of the Gotland Silurian, a solitary or phaceloid genus, may likewise be a member, but it differs from the others in having a wider septal stero- zone and a noncompact subcylindrical growth habit. Some corals here placed in the Endophyllidae have previously been assigned to Spongophyllum. Spongo- phyllum is typified by S. sedgwicki Edwards and Haime; this genus is not included in the Endophyllidae as here re- defined by reason of its slender corallites, rather narrow tabularium, and narrower, simpler, and possibly only sparingly lonsdaleioid dissepimentarium. It is proposed that the generic name Spongophyllum be confined to species agreeing in general structure and proportions with the Devonian S. sedgwicki as originally illustrated by Edwards and Haime (1853, pl. 56, figs. 2, 2a-c, 2e). These illustrations show a thickened wall and little suggestion of lonsdaleioid dissepiments in four of the five transverse views. A single figure (2d) of Edwards and Haime's plate 56 shows a lonsdaleioid pattern. There is no assurance that the specimen so illustrated (2d) is conspecific. (See also Stumm, 1949, p. 31, pl. 14, figs. 10, 11; Birenheide, 1962, p. 68-74, pl. 9, fig. 8, and pl. 10, fig. 10). Lonsdaleioid dissepiments occur in several rugose coral families and by themselves are not regarded as indicative of genetic relationships. In the Silurian rocks, dissepiment patterns of this kind characterize the Endophyllidae and genera of other families, such as Strombodes, Kypho- phyllum, Pilophyllum, Spongophylloides, and Ketophy- llum. Of the various Devonian rugose coral groups so characterized, several of cerioid growth habit have rather indiscriminately been classified as Spongophyllum. Some of these, may more appropriately be assigned to Austra- lophyllum, whereas others are perhaps allied to Hexa- gonaria. The rather abundant Late Paleozoic columellate corals of Lonsdaleioid habit are typified by Lonsdaleia. Abbreviation and loss of septa is a tendency manifested by the later Silurian Endophyllidae; among these are Yassin, - which lacks septa,. Australophyllum (Toquimaphyllum), with septa reduced or lost in some corallites, and the undescribed Klamath Mountains genus with similarly reduced or obsolete septa. Genus AUSTRALOPHYLLUM Stumm, 1949 Spongophyllum cyathophylloides Etheridge, p. 7, 8, pl. A, fig. 8; pl: C. figs. 1, 2. 1949. - Australophyllum Stumm, p. 34, pl. 16, figs. 1, 2. 1911. 1956. - (?) 4ustralophyllum cyathophylloides (Etheridge). Hill, fig. 207.4a, 4b. Type - species.-Spongophyllum _ cyathophylloides Etheridge; by author designation. "Lower Middle Devonian: Douglas Creek, Clermont, Queensland, Australia." Diagnosis.-Cerioid endophyllid corals with medium- wide to narrow, closely spaced, proximally sagging tabulae, and a wide to very wide dissepimentarium with scattered to wholly lonsdaleioid dissepiments, some of which are large. Remarks. -Australophyllum _ differs from Spongophyllum in possessing multiple columns of lons- daleioid dissepiments and more closely spaced sagging tabulae which lack a peripheral depression. Stumm's diagnosis of Australophyllum includes carinate septa, al- though his figures of the type species do not show these features convincingly. The wall of typical Australophyllum _ is - somewhat thickened - stereo- plasmically. Septal crests do not appear to be character- istic of Australophyllum sensu stricto, as they are of the new subgenus Toquimaphyllum. Subgenus TOQUIMAPHYLLUM, new subgenus 1888. - Endophyllum (spongophylloides?) Foerste, p. 131, pl. 13, figs. 16, 17. 1940. - Spongophyllum spongophylloides (Foerste). Hill, p. 408, pl. xiii, figs. 3-5. 1956. Spongophyllum. Hill, p. F298 (in part). Type species. -Australophyllum (Toquimaphyllum) johnson, n. sp.; here designated. Late Silurian coral zone E, Toquima Range, Nev. Diagnosis.-Cerioid rugose corals possessing mature corallites with wide, almost wholly lonsdaleioid dis- sepimentarium,. predominantly large dissepiments, and moderately wide to rather narrow, closely spaced, sagging tabulae without peripheral depression. Septa usually smooth, discontinuous peripherally as septal crests. In some mature corallites, septa greatly shortened or obsolete. Remarks.-Australophyllum (Toquimaphyllum) dif- fers from Australophyllum sensu stricto in the greater SYSTEMATIC AND DESCRIPTIVE PALEONTOLOGY development of large lonsdaleioid dissepimenits, in having an almost wholly lonsdaleioid mature dissepimentarium, in the presence of septal crests peripherally, and in the ten- dency to abbreviate and to lose septa in some corallites. Septa of Toquimaphyllum lack true carinae. Endo- phyllum differs in having a much wider tabularium, the tabulae being nearly flat to slightly arched medially with a peripheral sag not found in other described genera of this . family (Jones, 1929). The type species of Endophyllum shows a tendency to lose the outer wall, thus becoming aphroid or partly aphroid. Insofar as known, Endophyllum does not have the tendency to shorten and lose septa, as do Toquimaphyllum and other members of this family. Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. Plate 11, figures 1, 2, 5-7; plate 15, figure 17 Type material. -Holotype USNM 159420, Toquima Range, Nev.; paratype USNM 159422, Simpson Park Mountains, Nev. Late Silurian, coral zone E. Diagnosis.-Toquimaphyllum with major septa ex- tending to axis of normal corallites, breaking up peri- pherally as septal crests. Mature corallites with widest dis- sepimentaria having correspondingly narrow tabularia. Partially aseptate corallites retain only short inner-tip segments of major septa. Exterior. -Mature coralla compact globular heads with diameter commonly exceeding 1 foot. Individual corallites ranging from small to large at distal surface; calices moderately deep with no fossula and with raised rims formed by the thickened wall. A few corallites with a single peripheral calice offset bounded externally by a wall angulation. - Corallite wall - prominently . grooved longitudinally. Transverse sections. -About 38 septa in large normal corallites; in those with suppressed septa, number re- duced to 24 or fewer. Only axial tips of major septa retained in some reduced corallites. All septa dis- continuous peripherally, appearing only as crests in the lonsdaleioid band. Minor septa less continuous than major septa and commonly exceeding half the length of major septa. All septa more wavy and irregular toward axis; may be slightly thickened in tabularium. Wall moderately thickened stereoplasmically, forming obtuse wall crests. No true carinae. Symmetry entirely radial. Large and very large lonsdaleioid dissepiments pre- dominate. Longitudinal sections. -In widest corallites, eight or more lonsdaleioid dissepiment columns on each side. Outer dissepiments of large mature corallites nearly flat; innermost three smaller and steeply inclined. In wide corallites with narrow tabularium, tabulae from % to 4 the diameter. Tabulae delicate, crowded, complete or in- complete; proximal sag may be pronounced. No flat tabulae with peripheral sag. Tabularium sharply set off 55 from dissepimentarium. Some axial parts of septa with small lateral spines. Some longitudinal sections with numerous septal crests rising vertically from upper sur- faces of large nearly flat dissepiments. Fine structure. nearly normal to wall in stereoplasmic thickening; internal trabecular projections present but uncommon. Reproductive offsets. -A single offset in some calices. Small interstitial corallites common, in various stages of lonsdaleioid developnmient and septal suppression; most interstitial corallites with septa continuous to wall Comparison with related forms.-Closely related Toquimaphyllum occurs in the upper part of the middle unit of the Vaughn Gulch Limestone of the northern Inyo Mountains. Australophyllum (Toquimaphyllum) spongophylloides (Foerste) of the Yass-Bowning area, Australia (Hill, 1940, p. 408, pl. xiii, figs. 3-5), has wider tabulae but is otherwise very similar to johnson. Australophyllum (Toquimaphyllum) fritschi (Novak) of the Czechoslovakian Late Silurian as figured by (1902, pl. 102) does not reveal septal crests except for the wall crests and has a somewhat thicker wall and wider tab- ularium. The more distantly related endophyllids of the Silurian in the Klamath Mountains, Calif., have much wider, flat tabulae with peripheral sag and are viewed as a distinct genus. Australophyllum of the Early Devonian Rabbit Hill Limestone is not classified in this subgenus. Occurrence and age.-Late Silurian, coral zone E. Uppermost 200 feet of the Silurian, Coal Canyon, northern Simpson Park Mountains, Nev., localities M1026, M1106, M1108, M1335; Ikes Canyon, Toquima Range, Nev., locality M1114. Upper part of middle unit of Vaughn Gulch Limestone, Mazourka Canyon, Inyo Mountains, Calif.; locality M1115; these differ slightly from typical johnsoni. Australophyllum possibly be- longing in this species occurs in the Antelope Peak sec- tion 12 miles north of Wells, Elko County, Nev. Study material of this new form consists of 14 nearly complete and partial coralla, as follows: Locality M1114 (six), locality M1106 (three), locality M1108 (three), locality M1026 (one), locality M1335 (one). Five partial coralla were collected in the vicinity of locality M1115. Family ACERVULARIIDAE Lecompte, 1952 Reference genus and species. -Acervularia ananas (Linnaeus); Silurian, Wenlock, England. This family includes phaceloid and cerioid forms which have a fairly discrete inner wall dividing thedissepiment- arium from the tabularium; the inner wall is formed by stereoplasmic addition near ends of minor septa. Major septa may continue to axis. Tabulae either are complete and slightly arched or comprise tabellae with overall sag. The genera included in this family are Acervularia Schweigger, 1819, and Diplophyllum Hall, 1852. In the past, several Devonian species now classified as 56 SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Hexagonaria were erroneously placed in Acervularia. Gotland Silurian species placed in Rhabdophyllum Wedekind, 1927, also belong here as synonyms of Acervularia and possibly of Diplophyllum (Oliver, 1963, p. G2). Genus DIPLOPHYLLUM Hall, 1852 1956. - Diplophyllum Hall. Hill, p. F277, fig. 188.6a, 6b. 1963 Diplophyllum Hall. Oliver, p. G1; pls. 1-3. Type species. -Diplophyllum caespitosum Hall, by monotypy. Silurian, Lockport Dolomite, New York. Diagnosis.-"Compound rugose corals with a distinct inner wall of septal origin, separating the tabularium from a narrow peripheral dissepimentarium. The tabulae are mostly complete; dissepiments are flat to gently arched, forming a single series in each space bounded by the inner and outer walls and two adjacent septa." Remarks.-The diagnosis here given is that of Oliver (1963, p. G1), who has reviewed the systematics of this genus in the light of restudy of the type species and Hall's original material. i Diplophyllum? sp. m Plate 4, figures 10-14 Slender cylindrical corallites of a probable colonial form provisionally assigned to Diplophyllum? occur in the topmost beds of the Vaughn Gulch Limestone at Mazourka Canyon, northern Inyo Mountains. Some coral- lites of this weakly dissepimented species have more the character of Palaeophyllum than of Diplophyllum in lacking the false inner wall and peripheral column of dis- sepiments. A normal corallite in longitudinal thin section shows an outer column of rather flat dissepiments between a thin discontinuous false inner wall and the outer stereozone. Tabulae are straight or slightly arched and may bend sharply toward the periphery. In transverse thin section, the minor septa of a normal corallite may terminate against the thin false inner wall or may bend abruptly to meet an adjacent major septum near the false inner wall. As pointed out by Oliver (written commun., 1969), the false inner wall of sp. m appears to be of tabular origin and is not actually a true inner wall. As in some forms of D. caespitosum (Hall), the major septa of sp. m are continuous toward the axis of some corallites. However, the stereoplasmic swellings near tips of minor septa in caespitosum were not recognized in the Vaughn Gulch species. (See Oliver, 1963, pl. 2, fig. 1.) The Palaeophyllum-like corallites of this western form in transverse thin section resemble those of P. margaretae Flower (1961, pl. 48) but have much less arching of tabulae. Occurrence.-Northern Inyo Mountains, west side at mouth of Mazourka Canyon; locality M1090, within 20 feet of top of Vaughn Gulch Limestone. These beds are here considered to be either Late Silurian or Early Devonian. Genera with no family designation Genus SALAIROPHYLLUM Besprozvannikh, 1968 Salairophyllum? sp. Plate 12, figures 6-8 A solitary coral referred provisionally to the Russian genus is characterized by wide, more or less complete, close-spaced tabulae, a relatively narrow dissepimentarium and fairly wide septal stereozone. Septa of mature growth stages number about 56; some of the greatly thinned major septa reach the axis, longer minor septa are half the length of major septa. Septa are thickened stereoplasmically to a point beyond the stereo- zone, thinning markedly thence toward the axis. Some septa are minutely wavy with well-developed lateral spines which are not true carinae. Observed in longitudinal thin section, some of the wide close-set tabulae are nearly flat. Peripherally inclined trabeculae are especially well shown in the stereozone; some of these extend into the dissepimentarium as long spines like those of Tryplasmatidae. The small dis- sepiments are steeply inclined in two or three columns. The fully mature calice of the figured specimen shows four peripheral offsets. This coral is most closely related to undescribed Salairophyllum? from Kuiu Island, southeastern Alaska (loc. M1186), where it occurs with Conchidium alaskense. Septa are more numerous in the Alaskan species. The Russian S. angustum (Zheltonogova) has fewer septa and a wider stereozone. It occurs in strata reported by Shurygina (1968, p. 123) as Early Devonian; however, the Silurian- Devonian boundary fauna listed in association has a distinctly Gotlandian Silurian aspect. Occurrence.-Probably from upper Silurian coral zone E, upper beds of the Roberts Mountains Formation. Coal Canyon, northern Simpson Park Mountains, Nev. Float material, locality M1117, collected by R. J. Roberts. Genus DENAYPHYLLUM, new genus Type species. -Denayphyllum denayensis, n. gen, n. sp. Here designated. Silurian, type section of the Roberts Mountains Formation, Roberts Creek Mountain, Nev., upper 600 feet. Diagnosis.-Slender phaceloid rugose corals with about 12 fairly thin major septa which are slightly with- drawn from the axis; a wall which is thin to only moder- ately thickened; a single column of large, partly horizontal and fairly uniform dissepiments; and rather widely spaced, complete tabulae which are straight or have an axial sag. Remarks.-Denayphyllum _ resembles - Battersbyia Edwards and Haime, 1851, the type species of which-B. inaequalis Edwards and Haime-is reported from the Devonian of Teignmouth, Devonshije, England. The figures of Edwards and Haime (1853, pl. 47, figs. 2-2b, transverse sections only) represent B. inaequalis to have a LOCALITY REGISTER 57 thicker wall. Glinski (1957, p. 91-106) has reviewed in detail the classification and structure of Devonian corals of this kind from the Rhine River valley, Germany, pointing out that Fasciphyllum Schliiter, 1885, is a subjective synonym of Battersbyia. Glinski's longitudinal sections of Battersbyia show a thick wall and a more irregular arrangement of large elongate and small steeply inclined dissepiments which double here and there to form two columns, though in other places dissepiments are absent, as in Dendrostella Glinski, 1957. Denayphyllum differs from Columnaria Goldfuss in having much larger and more uniform, nearly horizontal dissepiments in a single column, and narrower tabulae. Denayphyllum denayensis, n. sp. Plate 7, figures 15-18 Type material. -Holotype USNM 159407. Diagnosis. -Denayphyllum with few or no minor septa and fairly straight corallites without connecting pro- cesses. Nearly horizontal dissepiments about one-third the diameter, or about same as width of tabulae. Transverse sections. -Average of 12 septa, but ranging from 10 to about 15, most slightly withdrawn from the axis, but some reaching the axis. Short minor septa un- common. Wall normally thickened slightly as a narrow stereozone. Septa usually thickened moderately and pro- gressively toward the periphery and somewhat wavy. Few dissepiments, only at the border of the tabularium. Longitudinal sections. -Characteristically, a single column of large dissepiments which are either almost horizontal or inclined axially; no specimens with doubling of dissepiments or places where these structures are lacking, as in Columnaria. Tabulae complete, widely spaced, most with a slight sag. In longitudinal section, corallite is divided into three columns, each one-third of the diameter, the tabulae being the middle third. Reproductive offsets.-None observed. Comparison with related forms.-No similar rugose corals are known from the American Silurian or Devonian. Only European species of the Middle Devonian assigned to Battersbyia are structurally comparable; the generic differences have been dealt with above. Occurrence.-Unit 3 in type section of the Roberts Mountains Formation, Middle Silurian, coral zone C. Roberts Creek Mountain, Nev. locality M1102. At locality M1102 this coral occurs in large tabular colonies. The study material consists of six pieces broken from one large colony collected in place. LOCALITY REGISTER North-central Great Basin Tuscarora Mountains, northern Eureka County, Nev.: Locality M287.-Near Elko-Eureka County line on east side of road between Dunphy and Tuscarora. Talus slope ai base of hill. Limestone with abundant silicified fossils of Silurian age, including Coelospira. Collected by R. J. Roberts, 1954. Locality M1120.-Tuscarora Mountains, at north end of Eure- ka County, Nev.; "Round Mountain," southwest end. Pro- bably the "Lynn Window" vicinity of R. J. Roberts. Silurian limestone with rugose corals. Collected by R. J. Roberts, June 1958. Southern Ruby Mountains, Nev.: Locality M1124.-Sherman Mountain quadrangle, Nevada. North of Sherman Mountain, 3 miles southeast of Mitchell Ranch on northeast side of Sherman Creek; altitude 8,400 feet. Sili- cified corals collected by Ronald Willden and R. W. Kistler, 1967. Northern Simpson Park Mountains, Nev.: Coal _ Canyon _ area; - Horse Creek - Valley _ quadrangle: Locality M1026.-East side of Coal Canyon near its mouth, SEX4 sec. 17, T. 25 N., R. 49 E.; altitude 6,820 feet. Coarse limestone breccia in upper part of the Silurian section, about 100 feet stratigraphically below the contact with the Lower Devonian (Helderberg) Rabbit Hill Limestone. Locality M1105.-Bottom of Coal Canyon, four-tenths of a mile south of its mouth; float material from upper part of the Silurian limestone on east side of canyon. Locality M1106.-Near mouth of Coal Canyon on east side; altitude 6,300 feet. Silurian coral-rich limestone breccia. Locality M1107.-About one-quarter of a mile south of mouth of Coal Canyon on east side; 200 feet above canyon bottom. Silurian coral-rich limestone breccia below Rabbit Hill Limestone. Locality M1108.-Near mouth of Coal Canyon, on east side; float material below Silurian limestone breccia. Locality M1110.-Vicinity of locality M1026. Collections made by A. J. Boucot, 1964. Locality M1I117.-NE4 sec. 20, T. 25 N., R. 49 E.; probably about six-tenths of a mile south of Coal Canyon mouth on east side of canyon. Collections made by R. J. Roberts, 1954. Central Great Basin Roberts Creek Mountain, Nev.; Roberts Creek Mountain quadrangle: Locality M1O89.-Northwest side of Roberts Creek Mountain; measured section on top spur between south and middle forks of Pete Hanson Creek, 2,500 feet N. 79° W. of summit 9219; altitude 8,500 feet. Base of unit 3 of type section of Roberts Mountains Formation. Locality M1101.-Same horizon and locality as locality M1089. Locality M1102.-Same measured section as locality M1089, about 100 feet stratigraphically above locality M1089. Lower beds of unit 3 with rugose coral fauna. Locality M1100. -Same measured section as locality M1089. 1,800 feet N. 79° W. of summit 9219; altitude 8,680 feet. Upper beds of unit 3 of Roberts Mountains Formation. Southern Sulphur Spring Range, Nev.; Garden Valley quadrangle: Locality M1121.-Dolomite hills 2 miles south-southwest of Romano Ranch, at east edge of range; eight-tenths of a mile S. 60° W. of bench mark 5825, on top of easternmost ridge; altitude 6,440 feet. Lone Mountain Dolomite, lower part with silicified fossils. Lone Mountain, Eureka County, Nev.; Whistler Mountain quadrangle: Locality M1122.-South side of Lone Mountain. Lone Moun- tain Dolomite with fragmentary rugose corals, four-tenths of a mile due south of summit 7360; altitude 6,840 feet. Southern Mahogany Hills, Nev.; Bellevue Peak quadrangle: Locality M1112.-About 14 miles due north of top of Wood Cone Peak, half a mile north-northwest of bench mark 7201 in lower foothills; altitude 7,350 feet. Upper part of Silurian Lone Mountain Dolomite with rugose coral fauna in dark- gray dolomite facies. 58 Southern Fish Creek Range, Nev.; Bellevue Peak quadrangle: Locality M1087.-West side of range at south boundary of quad- rangle, about 2,000 feet due south of summit 7232; altitude 7,000 feet. Lone Mountain Dolomite, upper part with silici- fied rugose coral fauna. Locality M1113.-At south boundary of quadrangle, four-tenths of a mile south-southeast of hill 7232; altitude 7,080 feet. Lone Mountain Dolomite, upper part with silicified coral and brachiopod fauna. West-central Great Basin Toquima Range, Ikes Canyon, Nev.; Dianas Punch Bowl quadrangle: Locality M1I088.-About 1 mile up Ikes Canyon from mouth; north side of canyon, 150 feet above bottom; altitude 7,840 feet. Silurian Masket Shale of Kay and Crawford (1964). Locality M1103.-Same locality and section as locality M1088, about 250 feet above canyon bottom; altitude 7,900 feet. Silurian - Masket Shale of Kay and Crawford (1964). Locality M1104.-Collections made by Kay and Crawford (1964) from their McMonnigal Limestone Ikes Canyon area. Probably from beds north of Ikes Cabin, north side Ikes Canyon, 14 miles northwest of mouth of this canyon. Locality M1114.-Ikes Canyon area, one-eighth of a mile north- west of summit 8474 (Copper Mountain); altitude 8,300 feet. Probably in McMonnigal Limestone of Kay and Crawford (1964)... Coral fauna of, Silurian coral zone E. South-central Great Basin Monitor Range, Dobbin Summit area, Nye County, Nev.: Locality M1123.-About 1 mile southeast of East Dobbin Sum- mit Spring, on east side of canyon. Silurian beds below Rab- bit Hill Limestone. Creek . Range, - Tybo . area, Nye: County, Nev.: Locality M1125.-Ridge north of town of Tybo; probably about 2,000 feet north of Cunningham prospect. Silurian dolomite above Eureka Quartzite. Hot Southwestern Great Basin Northern - Inyo - Mountains, - Calif.; Independence quadrangle: Locality M1I086.-Mouth of Mazourka Canyon; foothills on north side Vaughn Gulch, in NEX sec. 8, T. 18 S., R. 36 E. Northeast-southwest measured section. Lower unit of Silur- ian Vaughn Gulch Limestone, 550 feet stratigraphically above top of quartzite of Ordovician Johnson Spring Formation. (See fig. 3.) Locality M1I090.-Same measured section as locality M1086; beds of Late Silurian or Early Devonian age within 20 feet of top of Vaughn Gulch Limestone. Locality MIO91.-Same measured section as locality M1086; near east line of sec. 8, T. 13 S., R. 36 E.; altitude 4,840 feet. About 150 feet stratigraphically above chert unit at base of Vaughn Gulch Limestone. Locality M1092.-Same measured section as locality M1086; west of east line of section 8; altitude 4,880 feet. Middle unit of Vaughn Gulch Limestone, about 1,000 feet strati- graphically above Barrel Spring Formation. Locality M1I093.-Same measured section as locality M1086; upper unit of Vaughn Gulch Limestone between localities M1090 and M1092, about 1,350 feet stratigraphically above Barrel Spring Formation, 450 feet stratigraphically below top of Vaughn Gulch Limestone. Locality M1115.-Same measured section as locality M1086; about 110 feet stratigraphically below horizon of locality M1093. SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN Locality M1116.-Same measured section as locality M1086; coral bed 30 feet stratigraphically below locality M1098. Locality M1118.-Same measured section as locality M1086; fossil collections made between localities M1092 and M1093. Upper part of middle unit of Vaughn Gulch Limestone. Locality M1119.-Same measured section as locality M1086; middle unit of Vaughn Gulch Limestone, below locality M1092. Southern Inyo Mountains: Locality M1126.-New York Butte - quadrangle, California; 13,000 feet due north of Cerro Gordo mine, south side of Bonham Canyon; altitude 7,200 feet. Silurian dolomite with fossils. v Northern Panamint Range: Locality Mi094.-Ubehebe Peak quadrangle, California; 14 miles north of top of Ubehebe Peak, eight-tenths of a mile west: of bench mark 3765. About 200 feet stratigrpcally above base of Hidden Valley Dolomite in Silurian coral zone B. Locality M1095.-Quartz Spring area of J. F. McAllister; 22,600 feet S. 15° W. of Rest Spring, south side Andy Hills, in lower part of Hidden Valley Dolomite. Silurian coral fauna. Locality M1096.-Quartz Spring area of J. F. McAllister; 9,600 feet N. 86° E. of Rest Spring at Whitetop Mountain. Silur- ian corals in lower part of Hidden Valley Dolomite. Locality M1109.-Quartz Spring area of J. F. McAllister; 22,500 feet S. 18° W. from Rest Spring, south side of Andy Hills. Lower part of Hidden Valley Dolomite with Silurian corals. Locality M1111.-Ubbehebe Peak quadrangle, California; a- bout 1% miles north of Ubehebe Peak, at east foot of range and two-tenths of a mile east of locality M1094. Silurian coral float from lower beds of Hidden Valley Dolomite. Funeral Mountains: Locality M1097.-Ryan quadrangle, California; 1.95 miles N. 51° W. of Pyramid Peak. Lower part of Hidden Valley Dolo- mite with Silurian corals. Locality M1098.-Ryan quadrangle, California; $ miles S. 22° E. of Schwaub Peak. Silurian corals, lowest fossil collections in Hidden Valley Dolomite. Locality M1127.-Ryan quadrangle, California; 1.9 miles N. 59° E. from Pyramid Peak. Silicified Silurian fossils from cherty dolomite 100-150 feet above base of Hidden Valley Dolomite. Bare Mountain, Nevada: Locality M1085.-Bare Mountain quadrangle, Nevada; north- east side of Bare Mountain; south side of Tarantula Canyon near its head; near north edge sec. 36, T. 12 $., K. 47 £.; altitude 5,000 feet. Corals in lower part of Silurian section. Locality M1099.-Bare Mountain quadrangle, Nevada; Chuck- walla Canyon near mouth, on north side; altitude about 4,300 feet. Dark-gray Silurian limestone with corals, about 150 feet stratigraphically below contact with light-gray dolomite. Eastern Great Basin Confusion Range, Utah: Locality M1129.-Southern part of Confusion Range; NW4 sec. 25, 'E. 18 S., K. 16. W. /Isolated dolomite exposure containing Palaeocyclus and other Silurian Fossils Collected by R. K. Hose. Locality M1137.-Kings Canyon on U.S. Highway 6 and 50, near top of Confusion Range; Conger Mountain quadrangle. South side of road about 1,700 feet east of bench mark 5949; altitude 6,200 feet. Upper dark-gray Laketown Dolomite with Rhabdocyclus. Collected by A. J. Boucot. SILURIAN RUGOSE CORALS OF THE CENTRAL AND SOUTHWEST GREAT BASIN 59 REFERENCES CITED Amsden, T. W., 1949, Stratigraphy and paleontology of the Browns- port formation (Silurian) of western| Tennessee: - Yale Univ. Peabody Mus. Nat. History Bull. 5, 138 p., 34 pls., text figs. Barrois, Charles, 1889, Faune du Calcaire d'Erbray: Soc. Geol. Nord Mem., v. 3, no. 1, pl. 1-848, pls. 1-17. Bassler, R. S., 1937, The Paleozoic rugose coral family Paleocycli- dae: Jour. Paleontology, v. 11, no. 3, p. 189-201, pls. 30-32. 1950, Faunal lists and descriptions of Paleozoic corals: Geol. Soc. America Mem, 44, 315 p., pls. 1-20. Berry, W. B. N., and Roen, J. B., 1963, Early Wenlock grapto- lites from Roberts Mountains formation, Tuscarora Mountains, Nevada: Jour. Paleontology, v. 37, no. 5, pl. 1123-1126. Besprozvannikh, N. IL, 1968, Rugosy Tom'chum'yshskikh sloev Salaera [Rugose corals of the Tom'chum'yshskikh beds of Salair], in Ivanovsky, A. 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Survey Prof. Paper 4830-A, p. 1-9, pls. 1-4 [1963]. 1964, Silurian and Devonian corals of the Falls of the Ohio: Geol. 32, 33 cyathophylloides, Phaulacti 23, 43 Spongophyllum ————————————————— 54 Cyathophyllum perfoliatum -------------------- 52 plicat 52 cylindricum, Cystiphyllum--------------- 45 Cymostrophia sp ------------------ F 16 CYPRODhyUum 47 (Cystihalysites) magnitubus, Halysites - 15 Cystiphyllid@e-----------.-----.-.-.-.-.._._.--..-- 30, 45 Cystiphyllum cylindricum ---------------- 45 henryhOusense--------------------- 45 BHUPIEBG 45 OPM 45 Czechoslovakia, Toguimaphyllum ----------- 26 zone E correlation -------------------- 25 D Dal Il 14 dut 4 03m”. t 32 Dalmanophyllum -------------------- 23, 26; pl. 1 63 64 Page Dalmanophyllum ---------- 9, 20, 26, 29, 32 dalmani------------------ 23, 26; pl. 1 sp. A ------14, 20, 23, 26, 29, 32, 34; pl. 1 Dun... 42 Dasyclad 29; pl. 16 Del: phyllum 31 denayensis, Denayphyllum -14, 15, 30, 56, 57; pl. 7 Denayphylum -----------------.--..._....... 30, 56 denayensis-----------------14, 15, 30, 56, 57; pl. 7 Dendrostell 57 Depositional facies, coral-bearing rocks------ 5 Depositional features, Great Basin Silurian coralline rocks in relation to the reef PrObI&M -.-------..-...._._.~_........._.._.__~ 28 D phyllum 44 dewari, Petrozmm ——————————— --- 24, 26, 47 Dicael 14, 15, 20 Dinophyllum ---.... 32 Diplophyllum ————————————————————— 21, 30, 55, 56 p 56 BP: aioe -30, 56; pl. 4 Disphyllidae- 42 Disphyllum--------------------- 48 Distribution, Silurian coral-bearing rocks --- 5 Dolomite belt, eastern----------------------------- - 5, 6, 7 duncanae, Tryplasma~~--~14, 15, 24, 26, 30 , 37; pl. 1 Dyb ki 31 es 31 E Eastern dolomite belt ----------------- _ 5, 6 Eatoni 20 20 Endophyllidae---- 54 Endophyllum --- o 54 abditum-- 54 54 (spongophylloides) ------------------------------ I 54 . engelmanni, Entelophyllum--17, 25, 30, 49; pls. 10, 15 enorme, Rhizophyllum --------------------- -14, 16, 24, 46 Entelophylloides----------------- 4, 24, 26, 30, 47, 49, 50 (Entelophylloides) inequalis------------------------ 50 (PrOReX@gOn@ria) ----------------------- 24, 47 occidentalis --- 14, 15, 24, 26, 30, 50; pl. 9 Bp --- 50; pl. 9 (Entelophylloides) inequalis, Entelophylloides 50 inequalum, Entelophyllum ----------------------- 49 Entelophyllum -16, 22, 24, 25, 26, 29, 30, 37, 47, 48, 50, 51, 52; pl. 15 articulatum e 25, 48 engelmanni ------- 17, 25, 30, 49; pls. 10, 15 eurekaensis------------ 17, 25, 30, 49; pl. 10 25 Lone Mountain Dolomite--------------------- 13 pseudodianthus 48 (Entelophylloides) inequalum ---------------- 49 Eospirifer (Striigpirifer)----------------- 21 eurekaensis, Entelophyllum --- 17, 25, 30, 49; pl. 10 Evenkiell 24 F Facies, depositional and faunal, coral-bearing FOORG - 5, 18 Entelophyllum 7 Fardenia 20, 21 fascicularia, Tryplasma --- 34 fasciculatum, Entelophyllum -- 25 Fasciphyllum -------- 57 Faunal facies, coral-bearing rocks ------------ 5, 18 Favistell 32 Favisti 32 Fo i 16 fergusoni, Cyathophylloides-14, 20, 29, 33, 51; pl. 5 Fish Creek Range, southern, localities--------- 57 flabellata, Chonophylum--------- 24 52, 53 fletcheri, Acanthocyclu 38 PalQeOCYClus ---------------.-.------ 38 Rhabdocyclus 38 INDEX Page Fl trh .'u_ 3 4 34 fritschi, Australophyllum (Toquimaphyllum)- 25, 55 Funeral Mountains, localities -------------- --- 58 ZON€ B 20 G giganteum, Australophyllum (Toquimaphyl dotPH ) inn nnn lll 25 globulatus, Porpites ----- 39 Goniophyllidae --------------~-------------- 80, 46 Goniophyllum --- 46 pyramidalis --- S 46 gothlandica, Columnaria----------------------- 32 gothlandicus, Cyathophylloides ----------------- 33 Gotland, Sweden. See Sweden, Gotland. gotlandica, Calceola ------------------------ 46 gotlandicum, Microplasma 45 Rhizophyllum -------------- n 46 Graywacke belt, western (Pacific B0tdet)——-—-- 5 Great Basin Silurian section, age conclusions based on Silurian Rugosa------- 26 Iphensis, Pycnostylus 34, 35 H 43 14, 15, 17, 20, 21 (Cystihalysites) magnitubus --------- 15 hedstromi, Tryplasma ------------------- Hedstromophyllum Heliolites--------------------............-- 9, 14, henryh Cystiphyll hercynicus, Monograptus----------------------- ea 12 hesperalis, Protathyris--------------------------- 17 Hesperorthis------------------------ --- 54, 56 P“ dell 17 Holmophylum--~------................_... - 25, 45 Holophragma 44 He pira 15 Hot Creek Range, locality---------------- 58 Howellella pauciplicata------------- -- 16, 17, 21, 25 ithi 17 BD --no 16 Hur U 20 Huronia 20 Hyattidina 17 HYDDurite® ---.... 45 I Tkes Canyon reference section --------------- 9 zone A fauna--- 20 zone D fauna 21 ZONE E f@UN&---------------------- 21 inaequalis, Battersbyia ------------------- 56 inequalis, Columnaria----------------- 24, 49 Entelophylloides (Entelophylloides) --- 50 inequalum, Entelophyllum (Entelophylloides) 49 Intermediate limestone belt------------ 5, 7 intermedi Zelophyllum 40 Investigation, purpose, scope, and history --- i Inyo Mountains, localities----------------- 58 J, K johnsoni, Australophyllum (Toquimaphyllum) 14, 16 21, 22, 25, 26, 30, 54, 55; pls. 11, 12, 15 Toguimaphyllum----------------------.-~-- 25 kasandiensis, Ryderophyllum----------- 44 kassariensis, Cyathophylloides --------- 32, 33 kayi, Arachnophyllum --14, 20, 23, 30, 43 51 pl. 5 Kentucky, zone D correlation------------------- -- 24 Ketophyllum 52, 53, 54 kirbyi, Palae0¢yclus---------------- - 22, 39 Klamath Mountains, zone B correlation-------- 23 zone E correlation ----------------- 24 Kodonophyllidae ---------------------------- 30, 40 Page Kodonophyllinae 30, 40 Kodonophyllum----------------24, 25, 30, 40, 41 Milne-edward8si -------------------.----- 40 mulleri------------------14, 16, 24, 30, 41; pl. 4 24, 41 HURCQ@tUm---------......~-....... 41; pl. 4 . pl. 4 K 15 Bp --- zzz. lll 16 Kyphophyllidae--------------------------------- 30, 46 Kyphophyllum-16, 21, 22, 24, 25, 30, 47, 54; pl. 14 46, 47 nevadensis----------------- 14, 22, 30, 47; pls. 13, 14 L Laketown Dolomite--------------------- 16, 25 Leonaspis sp ------- --- 16 Leperditia 8p ------------------------- 16 Lept 21 liliiforme, Mycophyllum------------------ s 41 Limestone belt, intermediate------------------ 6..7 lindstromi, Kyphophyllum --- -~ 46, 47 Locality register ------------------- 87 Lone Mountain, locality--------- 57 Lone Mountain Dolomite------- 10 correlation with Laketown Dolormte- 25 fossils -------- -- 13 - 16 stratigraphy -------------- --- --- 16 Lone Mountain reference section -------------- 12 lonsdalei, Tryplasma------- «--.... 24, 25, 26, 87 LOn8d@lgigq--------------.--...._...._.._..«..«.. 54 30, 43 Gotland, Sweden ------------------- 26 M meallisteri, Palaeocyclus porpita---14, 30, 39; pl. 1 Petrozium --- --- 14, 24, 30, 48; pl. 9 Madrepora 39 truncata 40 Madreporites articulatus---------------------- 48 magnitubus, Halysites (Cystihalysites) --- 15 Mahogany Hills, southern, locality ----------- 57 MQiROHQ 34 EUTRESt@RICQ «---.... ---35; pl. 2 BD --no non eens. pl. 2 margaretae, Palaeophyllum -------------- a 34 Mazourka Canyon reference section---------- 8 zoOn€ A 20 zone D fauna--~---.-------~--............. AR 21 Merista-------------- 20 Meristella sp------ 16 Mesacti 45 michiganensis, Palaeocyclus-------------------- 39 Microplasma --- - 21, 30, 45, 46 45 mtlne-edwurdst, Kodonophyllum --- 40 Streptel 40 mitratum, Aulacophyllum ------ 45 mitratus, Hyppurites ------ 45 Pycnactis--- 45 mixta, Acervularia 51 Monitor Range, locality ---------- 58 Monograptus-----------------.--.----- beet 20 RerCyRiCUs ---------------- hees 12 ilssoni 25 12 riccartonengig -------------- nee 20 Mucophyllum----------------------- 30, 41, 53 41, 42 Oliveri-----------------14, 16, 24, 30, 42; pl. 5 mulleri, Kodonophyllum ----14, 16, 24, 30, 41; pl. 4 multicaule, Palaeophyllum---------------------- 34 teri, Conchidi a Mycophyllidae ---..-..~......-.....~............~....... 26 Mycophyllinge ---------------- 30, 41 Mycophyllum liliiforme------------------------ 41 N Page NQQ8 9 41 Neocystiphyllum -----------------~------- 44 Neomphyma-------------------- -25, 30, 47, 51, 52 crawfordi --- -- 14, 20, 30, 51; pl. 13 51 nevadensis, --- 22, 30, 47; pls. 13, 14 Stylopleura-------------- 14, 15, 30, 35; pls. 2, 15 New York State, zone A correlation----------- 22 24 newfarmeri, Tryplasma-14, 15, 24, 26, 30, 37; pl. 2 nilssoni, Monograptus-------------------------- eck 25 nordica, Tryplagma---------------.--..-.-..--- 37 0 identalis, Entelophylloides (Prohexag ia) 14, 15, 24, 26, 30, 50; pl. 9 oliveri, Mucophyllum------14, 16, 24, 30, 42; pl. 5 Omphyma flabellata ------------------ -- 52, 53 originalis, Australophyllum (Toquimaphyllum)22, 25 originata, NeomphymA@ ------------------------.----- 51 Orthoceras-like cephalopod ----------- 16 OrthOphyllum 20, 31 OrtRO8trODhi@ 8p 16 P 42 Pacific Border (Western) graywacke belt-------- 5, 27 pahranagatensis, Camarotoechia---------- --- 17 Palaeocyclus---17, 20, 22, 23, 25, 26, 30, 31, 36, 39; pl. 15 geeks 38 monn --- 22, 30 mirhignnpy. i 39 POTDita-------..........~~ 20, 26, 39; pls. 1, 15 14, 23, 30, 39; pl. 1 rotuloide 39 it 32 Palaeophyllum--------------- --21, 22, 30, 33, 40, 56 mMargaretae -------------- 34 multi l 34 r 33 ERO 34 Bp. lll ~ 30, 34; pl. 3 sp. c mcs 30, 34; pl. 2 Panamint Range, northern, localities ----------- 58 northern, reference section --- - 12 Papiliophyllum ---------------------- 4 43 patellatum, Chonophyllum----------------- 52 Schlothelmophyllum~————~———~— 24, 42 p licata, He Hell 16, 21, 25 pegramense, Cy@thactig-------------- 44 pentagonum, Arachnophyllum--~--------- 42, 48 Pentamerids, Conchidium-like----------- 20, 21, 26 perfoliatum, Chonophyllum ----------------- 52, 53 CyathOphyllum------------------------- 52 Petrozium--------- 21, 23, 24, 26, 30, 47, 51 dewari eo --- 24, 26, 47 meallisteri --- 14, 24, 30, 48; pl. 9 Phaulactis--------- ---.----23, 24, 44, 45 Cyathophylloides ----------------------- 23, 43 Phillipsastraeidae -- - 42 Pholidophyllum --- --- 36 Pilophyllum--------- planum, Chonophyllum ----------------------- 52 22, 24 BD -on mone 16 plwatum, Cyathophyllum----------------- 52 Polyorophe 37 porpita meallisteri, Palaeocyclus-14, 23, 30, 39; pl. 1 Madrepora---------------------_---- 39 Palaeocyclus - 20, 26; pls. 1, 15 Porpit 39 Porpites 39 globulatus-- 39 -- eme 39 porpitoides, Acanthocyclus 38 INDEX Page praechercynicus, Monograptus------------- 12 DrAV@, Trypl@8ma------------------_-_---- 24 Pytchopleurella 21 prima, Brachyelusma ooo 31 Dybowakta—-—-———-———-—~--—-—-~—-———---- 31 Proh 30, 50 (Prohexagonarm) Entelophylloides--------- 24, 47 occidentalis, Entelophylloides -14, 15, 24, 26, 30, 50; pl. 9 sp., Entelophylloides ---------------------- 50; pl. 9 Protathyris hesperalis----------------------- 17 Pseudamplexus- - 41 pseudodianthus, Entelophyllum 48 dohelianthoides C’- phyllum 52 Ptychophylhdae—————n_.— ......... 42 Ptycophyllum Be- 44 Ptych ella 20 Purpose of investigation --------------------- 1 Pycnactis 20, 21, 23, 26, 30, 44, 45 mitratus e 45 BDD. Koerner 14, 30, 45; pl. 6 Pycnostylidae----------- -.... 80, 86 ® 34 guelphensis $4, 05 sp --- | BD. 15 pyramidalis, Goniophyllum-------------------------- 46 Q, R Quadrithyris zone, coral zone E ----------------- exe 12 Rafi ina sp- 16 rectiseptatum, Spongophyllum --------------------- - 24, 26 Reference sections, Coal Canyon --- - 10 Great Basin Silurian --------- % 8 Ikes Canyon-------- s 9 zone A f@una 20 zone D f@UN&@ -------------..-.---.-..~--- 21 zone E fauna--------------- 21 Lone Mountain------------------- 12 Mazourka Canyon ------------------ 8 zone A fauna ------------ 20 zone D fauna o 21 northern Panamint Range --------------- 12 Roberts Creek Mountain---------------- 10 zone A f@UNA ---. 20 zone B 21 2006 C 21 zone E fauna----------.......-.-....._...- 21 Rhabdocyclus---------------------------30, 36, 37, 38 38 ————— 30, 38; pl. 1 90, 86; pl. 1 88; pl. 15 Rhabdophyllum--———- 56 Rhegmaphyllum------- -~ 29, $1 turbinatum -------- 31 Bp. --14, 29, 31; pL 1 r‘,.’.’.. r 31 Rhipidi 21 Rhizophyllum---------------- --24, 25, 26, 27, 30, 46 re 14, 16, 24, 46 gotlandicum ---------------- 46 sp. A ien 46 Bp. 14, 22, 30, 46; pl. 7 Rhynchospirina sp---------- 16 Rhyttdophyllum ............................ 46 riccar i grapt 20 richteri, Kodonophyllum -------------------------------- 24, 41 Roberts Creek Mountain, localities------------ 57 Roberts Creek Mountain reference section, zone A fauna--------------- 20 zone B fauna---------.--..........._....... 21 zone C fauna P 21 zone E 21 Romingerella 21 rotuloides, Pal yclus 39 Ruby Mountains, southern, locality------------- 57 zone A fauna meee 20 Rugosa, Silurian, age determinations - 26 65 Rugosa-Continued Page Silurian, basis of characterization --------- 4 characteristic, by zones -------- 14 classification----------------------- 29 correlation with distant Silurian rocks 22 correlation within Great Basin --------- 17 rugosum, Palaeophyllum-------------- 33 Ryderophyllum-------20, 21, 23, 24, 26, 30, 44, 45 Rasandiensig ----------------------- 44 ubehebensis-------------------14, 30, 44, 45; pl. 6 Bp «--- zzz ene. 16, 22; pl. 6 S Salairophyllum------------------------ 16, 24, 30, 56 income 56 Bp 30, 56; pl. 12 Salopir 17 dali m {V 1 I 46 Gah ollhni i) sp 16 Schlotheimophyllum 23, 25, 26, 40, 41, 42, 53 patell 24, 42 Scope of investigation ----------------------- h sedgwicki, Spongophyllum -------------------- 54 Sharopshire, England, zone B correlation---- 24 Siberia, zone C correlation ---------------- 24 Sicorhyncha an rem 16 Silurian coralline rocks, Great Basin, com- pared with those of other regions-- 27 Silurian Rugosa, age determinations -------- 26 correlation with distant rocks---------- 22 correlation within Great Basin --- 17 Silurian System, identification in Great Basin 4 siluriense, Cystiphyllum ---------------- --- 45 Simpson Park Mountains, northern, localities- _ 57 simpsoni, Chonophyllum---14, 16, 24, 30, 53; pl. 8 Tonkinaria --------------- 14, 15, 30, 51, 52; pl. 7 Siphonophrentis (Breviphrentis) ------------- 31 smithi, Howellella 17 ialis, Cyathacti 44 Sulunup- ac 29 speciosa, Arachnophyllum ----------------- 43 Spiniferina 36 SpOngOphyUOides ---------------------- 25, 54 (Spongophylloides), Endophyllum --- b4 spongophylloides, Australophyllum (Toqui- HEGORYUALDH 25, 55 Spongophyllum ---------------------- 54 54 CyathophyllOides ---------------------- 54 recti 24, 26 J‘= obi 54 SPON&OpPhylOides-------~-------------- 54 Stauria astreiformis-------------- --- - 32 Stauriidae ------------ -29, 32, 33 stellaris, Strombodes --- 48, 47 36 Stratigraphy, Laketown and Lone Mountain DOIOMMite 16 Streptelasma 31 cornicul 30 Milne-@dW@rd8i -----------------~---- 40 Streptelasmatldae-——-——————— ————— 29, 30 Streptel 29, 30 (Striigpirifer), Eospirifer--------------- 21 Strombodes------------------------47, 50, 54 -----------~----~--~---------- 48, 47 ~- ees 42 Study Methods------------------------ 2 Stylopleura-------------21, 22, 26, 30, 34, 40; pl. 3 berthiaumi-------- 14, 15, 21, 30, 34, 35, 36; pl. 3 nevadengig--------------- 14, 15, 30, 35; pls. 2, 15 sp. T------ - BD --- -c ccc ccc ~ --- pl. 16 Sulphur Spring Range, southern, locality --- 57 Swe {@M, GOtIANd ------------------------ 22 «otland, Lykophyllidae ---------------------- 26 thickness of Silurian System --- 28 zone A correlation------------ __ 22 zone B correlation 23 zone C correlation------------ -- 24 66 Sweden-Continued Page Gotland-Continued zone D correlation------------------ 24 zone E correlation----------------- 24 15, 84 T Tennessee, zone D correlation-------------- 24 T r LJII 50 tenuiseptatus, Cyathactis ----------------------- 44 Teratophyllum 46 thomi, Palaeophyllum -------- 34 Tonkinaria----------.--...-......-. 21, 30, 47, 51; pl. 7 simpsoni -------------14, 15, 30, 51, 52; pl. 7 Toquima Range, localities -------------------------- 58 Toquimaphyllum------16, 22, 23, 24, 25, 26, 30, 54 - 25 (Toquimaphyllum), Australophyllum -22, 54; pl. 11 fritschi, Australophyllum -------------- 25, 55 giganteum, Australophyllum ---. 25 johnsoni, Australophyllum---14, 16, 21, 22, 25, 26, 30, 54, 55; pls. 11, 12, 15 originalis, Australophyllum ------- 22, 25 spongophylloides, Australophyllum ------- 25, 55 truncata, Madrepora------------------------- 40 INDEX Page truncatum, Kodonophyllum - --- 4l;pl. 4 Tryplasma ------- --21, 25, 30, 31, 36, 37 quabil 36 DrOWNSPOrten$i$ ---------------...............-.. 24 duncanae -- ---14, 15, 24, 26, 30, 37; pl. 1 fascicularia 34 hedstromi on ace 20, 24 24, 25, 26, 37 newfarmeri--------- 14, 15, 24, 26, 30, 37; pl. 2 nordica 37 prava ve noe oen 24 sp. R ___ z _._ 30, 38; pl. 1 BD --- pl. 10 Tryplasmatidae 30, 36 tubiforme, CystiphyUum-------------------.----- igs 45 turbinata, Turbinolia------- 31 turbinatum, Rhegmaphyllum------------------- ase 31 Turbinolia turbinat 31 turkestanica, Maikotti 35; pl. 2 Tuscarora Mountains, localities ------------ -- 57 zone A f@una-----.---.----....._..._.._-- creates 20 typus, Arachnophyllum ------------------ 22, 23, 42, 43 -»» cocoon 44 42 Page Tyria 32 U, V, W ubehebensis, Ryderophyllum ----14, 30, 44, 45; pl. 6 Ural Mountains, zone C correlation ------------- 24 Verticillopora-------------9, 15, 20, 21, 22, 25, 26 Annulata----------------.--.-......_..._---29; pl. 16 Virgiana 4 Western (Pacific Border) graywacke belt------ - 5, 27 x.¥.% Xylodes 48 sp -- 51 Yassia 54 Zaphrentis COnulus -------------............... 31 Zelophylum 30, 36, 37, 40 intermedi 40 Zonation, Rugosa, Great Basin Silurian----- 13 PLATES 1-16 [Contact photographs of the plates in this report are available, at cost, from the U.S. Geological Survey Photographic Library, Federal Center, Denver, Colorado 80225] FIGURES 1-3. .: j2-18. 17. 16. 18-21. 22, 28. 24, 25. 26-28. 29, 30. PLATE 1 Dalmanophyllum sp. A. 1, 2. Lateral and calice views (x 2); USNM 159360. Lower Silurian, coral zone A, lower unit of Vaughn Gulch Limestone; locality M1091, Mazourka Canyon, northern Inyo Mountains, Calif. 3. Calice view (x 2); USNM 159361. Lower Silurian, coral zone A, lower member of Hidden Valley Dolomite; locality M1096, Whitetop Mountain, Ubehebe dis- trict, California. . Dailmanophyllum dalmani (Edwards and Haime). Lateral view (x 2); Flint Ridge, Ohio. Copy of Edwards and Haime holotype figure (1851, pl. 1, fig. 6). . Brachyelasma sp. Transverse and longitudinal thin sections of same individual (x 2), USNM 165355. Middle Silurian, coral zone B, lower part of Hidden Valley Dolomite; locality M1098, Ryan quadrangle, Funeral Mountains, Calif. Rhegmaphyllum sp. h. Calice and lateral views (x 2); USNM 159362. Lower Silurian, coral zone A, lower member of Hidden Valley Dolomite; locality M1096, Whitetop Mountain, Ubehebe district, California. . Brachyelasma sp. B. 9, 10. Transverse and longitudinal thin sections of same individual (x 2); USNM 159363. Middle Silurian, coral zone B, lower part of Hidden Valley Dolomite; locality M1094, Ubehebe district, California. 11. Longitudinal thin section (x 2), USNM 165352. Coral zone B, lower part of Hidden Valley Dolomite; locality M1097, Ryan quadrangle, Funeral Mountains, Calif. Palaeocyclus porpita subsp. meallisteri, n. subsp. 12. Edge view of paratypes (x 3); USNM 159364. 13, 14. Bottom and calice views of holotype (x 3); USNM 159365. 15. Calice view of paratype (x 2); USNM 159366. 17. Calice view of paratype (x 2); USNM 159367. Lower Silurian, coral zone A, lower member of Hidden Valley Dolomite; M1096, Whitetop Mountain, Ubehebe district, California. Palaeocyclus porpita cf. subsp. meallisteri, n. subsp. Calice view (x 2%); USNM 159368. Lower Silurian, coral zone A; locality Confusion Range, Utah. Palaeocyclus porpita (Linnaeus). 18, 21. Calice and edge views, same individual (x 2); USNM 159369. 19. Edge view (x 2); USNM 159370. 20. Edge view of broken individual (x 3), showing calice and trabeculae; 159371. Lower Silurian, Visby, Gotland, Sweden. Rhabdocyclus sp. d. 22. Calice view (x 4), showing trabecular spines; USNM 159372. 23. Lateral view of broken individual (x 2), showing calice and trabecular USNM 159373. Lower Silurian, coral zone A; locality M1096, Whitetop Mountain, Ubehebe district, California. Rhabdocyclus sp. B. Calice views of two large individuals (x 1%); USNM 165353a, 165353b. Silurian; locality M1099, Chuckwalla Canyon, Bare Mountain quadrangle, Nevada. Tryplasma duncanae, n. sp. 26. Lateral view of holotype (x 2); USNM 159374. 27. Calice view of paratype (x 5); USNM 159375. 28. Longitudinal thin section (x 2%); USNM 159376. Middle Silurian, coral zone D, unit 3 of Roberts Mountains Formation; locality M1100, Roberts Creek Mountain, Nev. Tryplasma sp. R. Longitudinal and transverse thin sections (x 4); USNM 165354. Middle Silurian, bottom of coral zone C, base of unit 3 of Roberts Mountains Formation; locahty M1101, Roberts Creek Mountain, Nev. locality M1129, USNM spines; GEOLOGICAL SURVEY a 21 26 se 28 29" DALMANOPHYLLUM, BRACHYELASMA, RHEGMAPHYLLUM, PALAEOCYLUS, RHABDOCYCL US, AND TRYPLASMA 504-634 O - 73 - 6 FicurEs 1-4. 7-10. 11, 12: 13, 14. 15, 16. PLATE 2 Tryplasma newfarmeri, n. sp. 1. Longitudinal thin section (x 3); holotype, USNM 159377. 2, 3. Longitudinal views of a single thin section (x 4); holotype, USNM 159377 4. Transverse thin section (x 2); holotype, USNM 159377. Silurian, coral zone C, unit 3 of Roberts Mountains Formation; locality M1102, Roberts Creek Mountain, Nev. . Palaeophyllum? sp. c. Longitudinal and transverse thin sections (x 2). Lower Silurian, lower unit of Vaughn Gulch Limestone; locality M1086, northern Mazourka Canyon, Inyo Mountains, Calif. Stylopleura? sp. T. Transverse and longitudinal sections of USNM 159378. 7. Smoothed surface photographed in water (x 1). 8-10. Thin sections (x 1%). Silurian or Lower Devonian limestone; locality M1104, Ikes Canyon vicinity, Toquima Range, Nev. Stylopleura nevadensis, n. gen., n. sp. Transverse and longitudinal thin sections of paratype (x 4); USNM 159379. Middle Silurian, coral zone D, Masket Shale of Kay and Crawford (1964); locality M1103, Ikes Canyon, Toquima Range, Nev. Maikottia sp., cf. M. turkestanica Lavrusevich. Transverse and longitudinal thin sections (x 2) of large massive colony. Upper Silurian or Lower Devonian; Porcupine River, half a mile upstream from mouth of Salmontrout River, Alaska. Stylopleura nevadensis, n. gen., n. sp. 15. Transverse thin section (x 2); paratype, USNM 159440. 16. Longitudinal section (x 1%); paratype, USNM 159440a. Upper part of the Silurian section; locality M1105, Coal Canyon, northern Simpson Park Mountains, Nev. PROFESSIONAL PAPER 777 PLATE 2 GEOLOGICAL SURVEY STLOPLEURA, AND MAIKOTTIA TR YPLASMA, PALAEOPHYLLUM2, PLATE 3 FigurESs 1-3. Stylopleura cf. S. berthiaumi. 1. Lateral view of part of a fasciculate colony (x 1); USNM 165356. 2, 3. Transverse and longitudinal sections (x 2). Silurian; locality M1099, Chuckwalla Canyon, Bare Mountain quadrangle, Nevada. 4, 5. Palaeophyllum sp. b. Transverse and longitudinal sections (x 2%); USNM 165357. From large phaceloid colony. Lower part of Silurian section; locality M1085, Bare Mountain quadrangle, Nevada. 6-8. Stylopleura berthiaumi, n. gen., n. sp. Calice and two lateral views (x 1); USNM 159380. Upper Silurian, coral zone D; locality M1103, Ikes Canyon, Toquima Range, Nev. 9-17. Stylopleura berthiaumi, n. gen., n. sp. 9, 10. Calice view and longitudinal polished section of paratype (« 1); USNM 159381. 11. Partial lateral view of holotype (x 1%); USNM 159382. 12. Calice view of paratype (x 2), showing multiple calice budding; USNM 159383. 13. View of broken calice interior, showing three offsets (x 2). 14. Partial lateral view of paratype (x 1), showing lateral pillar attached to Cladopora branch; USNM 159384. 15, 16. Longitudinal thin sections (x 2); USNM 165358a, 165358b. 17. Lateral view of a piece of a large colony (x 1), showing connecting pillars; USNM 165359. Upper Silurian, coral zone D, unit 3 of Roberts Mountains Formation; locality M1100, Roberts Creek Mountain, Nev. 18-20. Stylopleura berthiaumi, n. gen., n. sp. Partial interior view of calice offsets and lateral view and calice view of same individual (x 1), showing multiple calice budding and bases of lateral pillars; USNM 159385. Upper Silurian, coral zone E; locality M1106, Coal Canyon, northern Simpson Park Mountains, Nev. GEOLOGICAL SURVEY PROFESSIONAL PAPER 777 PLATE 3 STYLOPLEURA AND PALAEOPHYLLUM PLATE 4 FIGURES 1, 2. Kodonophyllum truncatum (Linnaeus). 1. Transverse thin section (x 2). Silurian, Wenlock Limestone; Dudley, England. 2. Longitudinal thin section (x 3). Silurian; Lilla Karlso Island (off Gotland), Sweden. Both figures copied from plate viii, Smith and Tremberth, 1929. 3-7. Kodonophyllum mulleri, n. sp. 3. Longitudinal thin section (x 2) of holotype; USNM 159386. 4. Longitudinal thin section (x4) of holotype; USNM 159386. Enlargement of part of fig. 3. 5. Transverse thin section (x 2) of holotype; USNM 159386a. 6. Transverse thin section (x 4) of holotype; USNM 159386b. Upper Silurian, coral zone E; locality M1108, Coal Canyon, northern Simpson Park Mountains, Nev. 7. Transverse thin section (x 1%) of paratype; USNM 159389. Upper Silurian, coral zone E; locality M1107, Coal Canyon, northern Simpson Park Mountains, Nev. 8, 9. Kodonophyllum sp. a. Transverse sections of ephebic stage (x 4). Silurian; Gotland, Sweden. Both figures copied from plate X, Minato, 1961. 10-14. Diplophyllum? sp. m. Transverse and longitudinal thin sections (x 3%), USNM 165350. Upper Silurian or Lower Devonian, topmost beds of Vaughn Gulch Limestone; Mazourka Canyon, Inyo Mountains, Calif. 15, 16. Crassilasma? sp. Longitudinal and transverse thin sections (x 2), USNM 165351. Middle Silurian, middle unit of Vaughn Gulch Limestone; Mazourka Canyon, Inyo Mountains, Calif. GEOLOGICAL SURVEY PROFESSIONAL PAPER 777 PLATE 4 i A % * 15 KODONOPHYLLUM, DIPLOPHYLLUM, AND CRASSIL ASMA? PLATE 5 FicurEs 1-6. Mucophyllum oliveri, n. sp. 1. Transverse section of holotype (x 1); smoothed surface photographed in water; USNM 159390. . Longitudinal thin section of holotype (* 2); USNM 159390. Enlargement of part of same thin section as fig. 2 (x 4), showing trabeculae; USNM 159390. . Part of transverse thin section of holotype (x 4), showing pattern of trabeculae; USNM 159390. . Calice view (x 1) of paratype; USNM 165349. . Longitudinal section of paratype (x 1), showing depth of calice pit; photographed in water; USNM 159391. Upper Silurian, coral zone E; locality M1108, Coal Canyon, northern Simpson Park Mountains, Nev. to po Ss o or 7, 8. Arachnophyllum kayi, n. sp. Transverse and longitudinal thin sections of holotype (® 8); USNM 159392. Lower Silurian, coral zone A, Masket Shale of Kay and Crawford (1964); locality M1088, Ikes Canyon, Toquima Range, Nev. 9, 10. Cyathophylloides fergusoni, n. sp. Transverse and longitudinal sections of holotype (x 8); USNM 159393. Lower Silurian, coral zone A, Masket Shale of Kay and Crawford (1964); locality M1088, Ikes Canyon, Toquima Range, Nev. GEOLOGICAL SURVEY PROFESSIONAL PAPER 777 PLATE 5 is at" h" fl Her r Hae A " 3,96?" he be got vin + + 2st ~ TC ' 8 10 C3 et a made" MUCOPHYLLUM, ARACHNOPHYLLUM, AND CYATHOPHYLLOIDES PLATE 6 FIGURES 1-7. Ryderophyllum ubehebensis, n. sp. . Transverse thin section of paratype (x 2); USNM 159394. . Longitudinal thin section of paratype (x 3); USNM 159395. . Transverse thin section of holotype (x 2); USNM 159396. . Longitudinal thin section of paratype (x 2); USNM 159397. . Longitudinal thin section of paratype (x 1); USNM 159398. . Lateral view of paratype (x 1); USNM 159441. . Transverse thin section of paratype (x 4); USNM 159399. Lower Middle Silurian, coral zone B, lower part of Hidden Valley Dolomite; locality M1094, Ubehebe district, California. 8. Ryderophyllum sp. Transverse thin section (x 2). Upper Silurian or Lower Devonian, upper unit of Vaughn Gulch Limestone; locality M1093, Mazourka Canyon, Inyo Mountains, Calif. 9. Crassilasma? sp. Transverse thin section (x 2). Same locality as fig. 8. 10-12. Pyenactis sp. k. 10, 12. Lateral view (x 1) and transverse thin section (x 2) of same individual; USNM 159400. 11. Transverse thin section (x 2); USNM 150401. Lower Middle Silurian, coral zone B, lower part of Hidden Valley Dolomite; locality M1109, Andy Hills, Ubehebe district, California. 13, 14. Ryderophyllum? sp. 13. Transverse thin section (x 2). Upper Silurian, coral zone E; locality M1106, Coal Canyon, northern Simpson Park Mountains, Nev. 14. Longitudinal thin section (x 4). Upper Silurian, coral zone E; locality M1110, Coal Canyon, northern Simpson Park Mountains, Nev. G h i- GEOLOGICAL SURVEY * PROFESSIONAL PAPER 777 PLATE 6 RYDEROPHYLLUM, CRASSILASMA?, AND PYCNACTIS PLATE 7 FicurEs 1-8. Tonkinaria simpsoni, n. gen., n. sp. $ 1, 2 Lateral view (x 1%) of paratype; USNM 159402. 3, 4. Calice and lateral views of holotype (x 1%); USNM 159403. 5, 6. Transverse thin section (x 4) and longitudinal thin section (x 3%) of para- type; USNM 159404. 7. Transverse thin section (x 2); USNM 159405. 8. Calice view (x 2). Upper Silurian, coral zone D, unit 3 of Roberts Mountains Formation; locality M1100 Roberts Creek Mountain, Nev. 9. Tonkinaria cf. T. simpsoni. Lateral view of colony showing peripheral calice offsets (x 2); USNM 159406. Lower part of Hidden Valley Dolomite; locality M1097, Ryan quadrangle, Funeral Mountains, Calif. 10, 11. Microplasma? sp. R. Transverse and longitudinal thin sections (x 2). Middle Silurian, bottom of coral zone C, base of unit $ of Roberts Mountains Formation; locality M1089, Roberts Creek Mountain, Nev. 12-14. Rhizophyllum sp. D. Calice view (x 1), view of flat side (x 1), and transverse thin section (« 2) of same individual; USNM 121346. Upper Middle Silurian, middle unit of Vaughn Gulch Limestone; near locality M1092, Mazourka Canyon, northern Inyo Moun- tains, Calif. 15-18. Denaphyllum denayensis, n. gen., n. sp. 15. Transverse thin section of holotype (x 7%); USNM 159407. 16. Transverse thin section of holotype (x 15); USNM 159407. 17, 18. Longitudinal thin sections of holotype (x 15); USNM 159407. Middle Silurian, coral zone C, unit 3 of Roberts Mountains Formation; locality M1102, Roberts Creek Mountain, Nev. GEOLOGICAL SURVEY PROFESSIONAL PAPER 777 PLATE 7 TONKINARIA, MICROPLASMA?, RHIZOPHYLLUM, AND DENA YPHYLLUM PLATE 8 FiGurES 1-4. Chonophyllum simpsoni, n. sp. 1, 2. Transverse and longitudinal thin sections of holotype (x 1%); USNM 159408. 3. Enlargement of part of same longitudinal thin section as fig. 2 (x 4); USNM 159408. 4. Longitudinal thin section of paratype (x 2); USNM 159409. Upper Silurian, coral zone E; locality M1108, Coal Canyon, northern Simpson Park Mountains, Nev. 5, 6. Cyathactis? sp. 5. Transverse thin section (x 4). 6. Longitudinal thin section (x 4). Upper Silurian, coral zone E; locality M1106, Coal Canyon, northern Simpson Park Mountains, Nev. 7. Chonophyllum sp., cf.C. simpsoni, n. sp. Transverse thin section (x 4). Upper Silurian, coral zone E; locality M1110, Coal Canyon, northern Simpson Park Mountains, Nev. 8. Chonophyllum sp. Side view of weathered specimen (x 1). Upper Silurian or Lower Devonian, upper unit of Vaughn Gulch Limestone; locality M1093, Mazourka Canyon, northern Inyo Mountains, Calif. 9. Chonophyllum? sp. Calice view (x 1%). Middle Silurian, middle unit of Vaughn Gulch Limestone; locality M1092, Mazourka Canyon, northern Inyo Mountains, Calif. 10. Chonophyllum sp. Longitudinal thin section (x 4). Upper Silurian or Lower Devonian, upper unit of the Vaughn Gulch Limestone; locality M1093, Mazourka Canyon, northern Inyo Mountains, Calif. 11, 12. Chonophyllum? sp. Transverse and longitudinal thin sections (x 2). Upper Silurian or Lower Devonian, upper unit of the Vaughn Gulch Limestone; locality M1093, Mazourka Canyon, northern Inyo Mountains, Calif. PROFESSIONAL PAPER 777 PLATE 8 CHONOPHYLLUM AND CYATHACTIS? PLATE 9 FIGURES 1-4. Entelophylloides (Prohexagonaria) occidentalis, n. subgen., n. sp. 1. Transverse thin section of holotype (x 3); USNM 159410. 2. Enlargement of part of transverse thin section of holotype (x 6), USNM 159410. 3. Longitudinal thin section of holotype (x 3%); USNM 159410. 4. Longitudinal thin section of holotype (x 6); USNM 159410. Middle Silurian, coral zone C, unit 3 of Roberts Mountains Formation; locality M1102, Roberts Creek Mountain, Nev. 5. Entelophylloides (Prohexagonaria) sp. Transverse thin section (x 1%). Copied from pl. VIII, Smith and Tremberth, 1929. Visby, Gotland, Sweden. 6-10. Petrozium meallisteri, n. sp. 6-9. Transverse and longitudinal thin sections of holotype (x 6); USNM 159411. 10. View of part of fasciculate colony which is the holotype (x 1); USNM 159411. Lower Middle Silurian, coral zone B, lower part of Hidden Valley Dolomite; locality M1111, Ubehebe district, California. PROFESSIONAL PAPER 777 PLATE 9 GEOLOGICAL SURVEY Bx # Ca >€v'® % Rex ENTELOPHYLLOIDES (PROHEXAGONARIA) AND PETROZIUM 634 O - T3 - 7 504- FIGURES 1, 2. 12, 13. 14, 15. PLATE 10 Entelophyllum eurekaensis, n. sp. Transverse and longitudinal thin sections (x 4) of holotype; USNM 159412. Upper Silurian, upper part of Lone Mountain Dolomite; locality M1113, southern Fish Creek Range, Nev. . Tryplasma sp. Transverse and longitudinal thin sections (x 2). Upper Silurian, upper part of Lone Mountain Dolomite; locality M1087, southern Fish Creek Range, Nev. . Entelophyllum engelmanni, n. sp. 5. Transverse thin section of holotype (x 4); USNM 159413. 6. Longitudinal thin section of paratype (x 2%); USNM 159414. 7. Part of same thin section as fig. 6 enlarged (x 4); USNM 159414. 8. Longitudinal thin section of paratype (x 3%); USNM 159415. Upper Silurian, upper part of Lone Mountain Dolomite; locality M1112, southern Mahogany Hills, Eureka County, Nev. . Entelophyllum engelmanni, n. sp. 9. Transverse thin section of paratype (x 2); USNM 159416. 10. Lateral view of corallite (x 1%); USNM 159492. 11. Lateral view of two attached corallites (x 1). Shows attached shell of Howellella: Upper Silurian, upper part of Lone Mountain Dolomite; locality M1087, southern Fish Creek Range, Nev. Entelophyllum engelmanni, n. sp. 12. Oblique view of three corallites from large paratype colony, slightly reduced; USNM 159417. 13. Transverse thin section (x 2); USNM 159418. Upper Silurian, upper part of Lone Mountain Dolomite; locality M1112, southern Mahogany Hills, Eureka County, Nev. Entelophyllum eurekaensis, n. sp. Transverse and longitudinal sections of paratype (x 2); USNM 159419. Upper Silurian, upper part of Lone Mountain Dolomite; locality M1113, southern Fish Creek Range, Nev. PROFESSIONAL PAPER 777 PLATE 10 GEOLOGICAL SURVEY *0005 neg C _> 2s myt Jy # ~A zflgga ENTELOPHYLLUM AND TR YPLASMA PLATE 11 FigUrRES 1, 2. Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. Transverse and longitudinal thin sections of holotype (x 4); USNM 159420. Upper Silurian, coral zone E; locality M1114, Ikes Canyon, Toquima Range, Nev. 3, 4, Australophyllum (Toquimaphyllum) cf. johnsoni, n. subgen., n. sp. Calice view (x 1) and transverse thin section (x 2); USNM 159421. Upper Silurian, coral zone E; locality M1108, Coal Canyon, northern Simpson Park Mountains, Nev. 5, 6. Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. 5. Longitudinal thin section of paratype (x 4); USNM 159422. 6. Transverse thin section of same paratype (x 1%); USNM 159422. Upper Silurian, coral zone E; locality M1106, Coal Canyon, northern Simpson Park Mountains, Nev. 7. Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. Transverse thin section of holotype (x 2); USNM 159420. Same locality as figs. 1; 2. GEOLOGICAL SURVEY a PLATE 12 FicurEs 1-3. Australophyllum (Toquimaphyllum) cf. johnsoni, n. subgen., n. sp. Transverse thin section (x 2), transverse thin-section enlargment (« 3%), longitudinal thin section (x 4); USNM 149423. Upper Silurian, coral zone E, middle unit of Vaughn Gulch Limestone; locality M1115, Mazourka Canyon, northern Inyo Mountains, Calif. 4, 5. Australophyllum sp. 4. Transverse thin section (x 4). Middle unit of Vaughn Gulch Limestone; locality M1116, Mazourka Canyon, northern Inyo Mountains, Calif. 5. Transverse thin section (x 3%). Upper Silurian or Lower Devonian, upper unit of Vaughn Gulch Limestone; locality M1093, Mazourka Canyon, northern Inyo Mountains, Calif. 6-8. Salairophyllum? sp. 6. Transverse thin section (x 3); USNM 159424. 7. Longitudinal thin section (x 4); USNM 159424. 8. Transverse thin section (x 1%); USNM 159424. Note four peripheral calice offsets. Probably from Upper Silurian, coral zone E; locality M1117, Coal Canyon, northern Simpson Park Mountains, Nev. SSIONAL PAPER 777 PLATE 12 PROFE & motner 7 k & 6 5 c AUSTRALOPHYLLUM (TOQUIMAPHYLLUM}, AUSTRALOPHYLLUM, AND SAL AIROPHYLL UM CP PLATE 13 FicurEs 1-4. Kyphophyllum nevadensis, n. sp. 1, 2. Transverse and longitudinal thin sections of holotype (x 4); USNM 159425. 3. Transverse thin section of holotype (x 2); USNM 159425. 4. Transverse thin section of holotype (x 4); USNM 159425. Upper Silurian, coral zone E; locality M1114, Ikes Canyon, Toquima Range, Nev. 5-8. Neomphyma crawfordi, n. sp. 5-7. Transverse thin sections of holotype (x 4%); USNM 159426. 8. Longitudinal thin section of holotype (x 4); USNM 159426. Lower Silurian, coral zone A; locality M1088, Ikes Canyon, Toquima Range, Nev. PROFESSIONAL PAPER 777 PLATE 13 GEOLOGICAL SURVEY l aP ae < {gtiiinvw' poate Gt J‘nlvtfirllllr'l «Ow. ® % ' a t KYPHOPHYLLUM NEV ADENSIS, N. SP., AND NEMOPHYMA CRAWFORDI,N. SP. PLATE 14 FigurEs 1, 2. Kyphophyllum cf. K. nevadensis, n. sp. Transverse and longitudinal thin sections (x 4); USNM 159427. Upper Silurian or Lower Devonian, upper unit of the Vaughn Gulch Limestone; locality M1093, Mazourka Canyon, northern Inyo Mountains, Calif. 3, 4. Australophyllum sp. Transverse and longitudinal thin sections (x 4); USNM 159428. Middle Silurian, middle unit of the Vaughn Gulch Limestone; locality M1119, Mazourka Canyon, northern Inyo Mountains, Calif. 5. Australophyllum sp. Longitudinal thin section (x 7). Upper Silurian or Lower Devonian, upper unit of the Vaughn Gulch Limestone; locality M1093, Mazourka Canyon, northern Inyo Mountains, Calif. 6. Kyphophyllum cf. K. nevadensis, n. sp. Transverse thin section (x 2); USNM 159429. Middle unit of the Vaughn Gulch Limestone; locality M1118, Mazourka Canyon, northern Inyo Mountains, Calif. 7. Kyphophyllum cf. K. nevadensis, n. sp. Lateral view (x 1) of colony USNM 159427 from which thin sections shown in figs. 1, 2 were cut. Locality M1093. PROFESSIONAL PAPER 777 PLATE 14 GEOLOGICAL SURVEY fiWb £6.59 m 2 ot . im. "TPP - "gm“ * &. *a KYPHOPHYLLUM AND AUSTRALOPHYLLUM FigurEs 1-4. 10. 11. 12-16. 17. PLATE 15 Stylopleura nevadensis, n. gen., n. sp. 1. Upper surface of corallum (x %%); holotype USNM 159431. 2-4. Transverse thin section (« 2), longitudinal thin section (x 2), and longitudinal thin section (x 2) showing a connecting pillar; holotype USNM 159431. Upper Silurian, coral zone E; locality M1107, Coal Canyon, northern Simpson Park Mountains, Nev. . Rhabdocyclus sp. K. 5. 6. Calice and lateral views (x 2%), USNM 159432; note excentric apical cone. 7, 8. Calice and lateral views (x 4), USNM 159433. 9. Calice view (x 2), USNM 159434. Silurian, Laketown Dolomite; locality M1137, Kings Canyon, Conger Mountain quadrangle, Confusion Range, Utah. Palaeocyclus cf. P. porpita (Linnaeus). Calice view (x 2); USNM 159435. Silurian dolomite; locality M1336, 3 miles north- east of Mitchell Ranch, Sherman Mountain quadrangle, Ruby Mountains, Nev. Pycnostylus sp. Longitudinal sections (« 1%); USNM 159436. Silurian, Lone Mountain Dolomite; locality M1148, 3 miles south of Romano Ranch, Garden Valley quadrangle, southern Sulphur Spring Range, Nev. Entelophyllum cf. E. engelmanni, n. sp. 12. Lateral view of large corallite (x 1); USNM 159437. 13-16. Longitudinal and transverse thin sections (x 2) of corallite, USNM 159438. Silurian dolomite; 3 miles southeast of Mitchell Ranch, Sherman Mountain qua- rangle, southern Ruby Mountains, Nev. Australophyllum (Toquimaphyllum) johnsoni, n. subgen., n. sp. Calice view (x %) of part of colony; paratype USNM 159439. Upper Silurian, coral zone E; locality M1026, Coal Canyon, northern Simpson Park Mountains, Nev. GEOLOGICAL SURVEY p f PROFESSIONAL PAPER 777 PLATE 15 hegive rt ole a STYLOPLEURA, RHABDOCYCLUS, PALAEOCYLUS, PYCNOSTYLUS, ENTELOPHYLL UM, AND AUSTRALOPHYLL UM (TOQUIMAPHYLL UM) PLATE 16 FIGURES 1, 2. Brachyelasma sp. B. Longitudinal thin section and calice view of same individual (x 2); thin section shows incrustation by probable bryozoa on right. Middle Silurian, coral zone B, lower part of Hidden Valley Dolomite; locality M1127, Ryan quadrangle, Funeral Mountains, Calif. 3, 4. Stylopleura? sp. Lateral and calice views (x 1%). Silurian, lower part of the Lone Mountain Dolomite; locality M1121, southern Sulphur Spring Range, Nev. 5, 6. Verticillopora annulata Rezak. 5. Weathered interior (x 1%) showing ray bases. 6. Weathered specimen (x 2) showing internal stipe cavity. Upper Silurian, coral zone D, unit 3 of Roberts Mountains Formation; locality M1100, Roberts Creek Mountain, Nev. 7-13, 17. Verticillopora annulata Rezak. 7, 8. Longitudinal and transverse thin sections of same individual (x 2) showing internal stipe cavity and rays. 9, 10. Lateral and transverse views of same individual (« 1%). 11, 12. Lateral views of two large individuals (x 1%). 13. Lateral view of fragmentary individual (x 2) showing external pattern of pore cycles. 17. Longitudinal interior (x 3) showing ray pore cycles. Upper Silurian, coral zones D and E, upper part of middle unit of Vaughn Gulch Limestone; Mazourka Canyon, northern Inyo Mountains, Calif. 14. Verticillopora annulata Rezak. Lateral view (x 1). Upper Silurian, coral zones D and E, upper part of middle unit of Vaughn Gulch Limestone; Mazourka Canyon, northern Inyo Mountains, Calif. 15, 16. Verticillopora annulata Rezak. Exterior and transverse views of part of an annular segment (x 2) showing rays and ray pores. Upper Silurian or Lower Devonian, upper unit of Vaughn Gulch Limestone; - locality M1093, Mazourka Canyon, northern Inyo Mountains, Calif. GEOLOGICAL SURVEY PROFESSIONAL PAPER 777 PLATE 16 € £ 13 BRACHYELSAMA, STYLOPLEURA? AND VERTICILLOPORA U.S. GOVERNMENT PRINTING OFFICE : 1973 0-504-634 ' 3? s p x3 JE 75 us ; w* 7 DAY Tot 1.8138 L_ F sC_ Embudo, New Mexico, Birthplace of Systematic Stream Gaging msoite DEC 30 1971 NG 4777, Q? ~I Science 1B Embudo, New Mexico, Birthplace of Systematic Stream Gaging By ARTHUR H. FRAZIER and WILBUR HECKLER GEOLOGICAL SURVEY PROFESSIONAL PAPER 778 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY W. A. Radlinski, Acting Director Library of Congress catalog-card No. 72-180682 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1972 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 45 cents (paper cover) Stock Number 2410-2049 CONTENTS Page introduction ...i nne t th -a we srl tia a rika sl sin sl is 58 1 ProIlO8' ...... sel} .s ran nese rin et son sim s nie 4 sie ain 3 CamplEmbudo ' .l.......:... r iA AMY LL Fal ar risa Kink sia a a s a % 5 Camp personnel kiva laries lisa sakin ses igs 8 Stream-gaging operations 8 EpiiO® s salga ine hile a ie aie a alle anale n a f s 20 References ..........}...<» pS vhs an aia aik a nik a nw an nis a ais a lag 28 ILLUSTRATIONS Page FIGURE 1. Photograph of John Wesley Powell.................. 2 2. Map showing topography at Embudo, N. Mex. ....... 6 3-6. Photograph of- 3. Camp Embudo, N. Mex. (1888-89) .. .......... 9 4. Embudo campsite (1969) 9 5,6. Student hydrographers at Embudo............ 10, 11 7. Drawings of Saxton's tide gage..................... 12 8-10. Photograph of- 8. Raxton's tide 13 9. Embudo gaging station on the Rio Grande, N. Mex. (about 1889).;.................... .t.. 14 10. Denver and Rio Grande Railway station at Em- budo (about ufs 14 11. Drawing of evaporation pan........................ 15 12. Photograph of Haskell current meters............... 15 13. Discharge measurement notes, Rio Grande at San Mar- cial, N. Mex., August 8, 1889 .................... 16 14-20. Photograph of- 14. Nettleton current meters.................... 17 15. Upstream view at Embudo at old wagon bridge on which recording and staff gages were in operation 191214 ".................... 42. 18 16. Downstream view showing new (1914) record- ing gage shelter..................... .... 18 17. The present Embudo gaging station .......... 19 18. Upstream view of present gaging station...... 19 19. Clarence Edward Dutton ................... 21 20. Frederick Haynes Newell. .................. 22 III EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING By ArTHUR H. FRAZIER and WILBUR HECKLER INTRODUCTION Embudo, a tiny village on the Rio Grande in northern New Mexico, was chosen in 1888 to be the site of a training center for the first hydrographers of the Irrigation Survey, a new Bureau that had just been added to the U.S. Geological Survey under John Wesley Powell. This is the story of that center, but to make it more complete, a practice has been borrowed from the theater in that a prolog has been added for explaining the circumstances which led to the center's organization and an epilog, for presenting some of the distressing events which took place after the training period was completed. With these additions, this becomes the story of how the Geological Survey became involved in the art of stream gaging and how Powell was prevented from carrying out his plan for irrigation in the arid region-a plan which was largely adopted when Congress later established the Reclamation Service and the U.S. Bureau of Reclamation. EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING FIGURE 1.-John Wesley Powell (1834-1902). Photograph, supplied by Smithsonian Institution, Museum of Natural History, was taken about 1897. PROLOG John Wesley Powell (fig. 1) was to achieve, in 1881, the distinction of becoming the second Di- rector of the U.S. Geological Survey. His father, Rev. Joseph Powell, had been a licensed Episcopal preacher who had come from England to "spread the word of God" in America-particularly through- out the frontier areas where he felt it was most needed. As the frontier moved westward, he too moved westward: from New York State (where John Wesley Powell was born) to Ohio, thence to Wisconsin, and finally to Illinois. During the course of those travels, there was added to Rev. Powell's intense religious drive, an almost equal drive to abolish slavery, and he expressed himself forcibly on both of those subjects. Fearless honesty and ex- treme forthrightness were two outstanding char- acteristics he handed down to his oldest son "Wes." (See. Pavis, 1915. p.. 83; Darrah, 1951, p. 11.) Those inherited characteristics ultimately (as will be shown later) led Wes into many difficulties. As a young man (during the years between 1867 and 1878) Powell crossed and recrossed the arid region of this country many times in connection with his studies of the American Indians and their languages; with his unprecedented boat expeditions down the Colorado River; and with his duties as Director of the Geographical and Geological Survey of the Rocky Mountain Region, one of the fore- runners of the present Geological Survey. It was during those years he conceived a need for a Fed- erally conducted Irrigation Survey. His hastily prepared and highly controversial "'Report on the Lands of the Arid Region of the United States" was delivered on April 1, 1878, to the Honorable J. A. Williamson, then Commissioner of the General Land Office. Williamson, in turn, forwarded it immediately to the Honorable Carl Schurz, then Secretary of the Interior. Within 2 days it reached the House Committee on Appropria- tions and was ordered to be printed. That edition was exhausted within a few months, and in March 1879 another edition of 5,000 copies was authorized by Congress. Stegner (1962, p. VII) who wrote the introduction to an edition of it which was published as recently as 1962, claims that it would ultimately be recognized as one of the most important books ever written about the West. | | | | | | | | | | | | | | | | i | | | | The report was devoted largely to the practica- bility of reclaiming by irrigation an appreciable per- centage of the arid region, the total area of which has been estimated at about 1,300,000 square miles, starting at about the 100th meridian (which cuts across the middle of the Dakotas and Nebraska) and extending westward beyond the Rocky Mountains to the southern Pacific coast. It is impractical to mention here all the innovations which were pro- posed in the report, but the substances of those which appeared in this and other reports of his, which are of primary concern at present, are listed below : 1. To take an inventory of the flow of all streams in the arid region in order to be able to eval- uate their potentials for irrigating nearby land areas. 2. To determine the average amount of water re- quired to irrigate each acre of that land during the growing seasons. 3. To prepare topographic maps on which to outline the drainage area of every stream which seemed to offer good possibilities for success- ful irrigation, and to declare those areas to be individual irrigation districts and locally inde- pendent political subdivisions. As many 80- acre farms were to be marked off on the map of each irrigation district as could be ade- quately irrigated by the quantity of water furnished by the stream (including whatever water could be stored from spring floods). 4. To provide the farmers in each district with plans and estimated costs of suitable dams (for impounding floodwaters) and canals (for de- livering equitable shares of the water to each farmer). After those facilities were con- structed under a cooperative program, they were to be considered as district-owned prop- erty. Before receiving any preemption right from the Government to enter any of these dis- tricts, the applicant would have to agree to participate in such a cooperative arrangement. His right to receive final title to any of that land was also contingent upon a showing that his entire farm had been under actual irrigation within 5 years of the date the district became organized. 4 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING 5. To abandon, in the arid region, the prevailing method of laying out political and land sub- divisions by the township, range, and section method. The last of those provisions was particularly im- portant in Powell's estimation because the prevail- ing method allowed settlers to acquire parcels of land through which streams were flowing without obligating them to permit settlers on any of the adjacent farms to have access to the water. Disputes arising from those circumstances seemed inevitable, and if the adjoining farms should happen to lie in another township, or in another county, any settle- ment thereof could become increasingly difficult. Under Powell's plan, the right to a fair share of the water was incorporated in every land grant, and the farmer automatically became a member of the very same political unit which had the authority to settle any local disputes. In some of Powell's subsequent reports was an item which, although it fell into another category, is nevertheless pertinent to this general discussion. It was a proposal that all the geologic and geo- graphic expeditions then authorized by Congress, such as those conducted by G. E. Wheeler, F. V. Hayden, Clarence King, and himself, be consolidated into a single Bureau. After obtaining advice from the National Acad- emy of Sciences on that and some of Powell's other proposals (Marsh, 1878, p. 2), Congress imple- mented only one of them-the one in which the several surveys were to be consolidated into a single Bureau. It was called the Geological Survey. The change became effective as of March 3, 1879. Clarence King was selected as the first Director of the new Bureau, whereas Powell became the head of the Bureau of Ethnology in the Smithsonian In- stitution. When, as of March 12, 1881, King resigned his position, Powell was appointed to succeed him, and for many years thereafter Powell remained in charge of both Bureaus (Davis, 1915, p. 47) -one in the Smithsonian Institution and the other in the Department of the Interior. During the 7 years following Powell's entrance into these new duties, the General Land Office con- tinued to process land grants in the arid region using the old land line method which Powell had so strong- ly opposed. And during that time also settlers were urged to move into that region, build homes, and plow the fields. It is interesting to note that during those years Powell's opponents made strong efforts to popularize a theory that, when prairie lands are plowed under, rains would occur as a consequence thereof. And because those particular years started with an unusually long rainy period, people began to believe the slogan, "Rain follows the plow." Under the prevailing circumstances, Powell's recommenda- tions lost much of their force. He nevertheless per- sisted in repeating them and thereby brought down upon himself the wrath of many westerners whose part of the country the plan was particularly in- tended to benefit. When that exceptionally long rainy period finally ended, Nature gave Powell's cause a helping hand. It was accomplished in two devastating strokes: (1) in 1866 an unprecedented cold winter occurred dur- ing which most of the livestock, and many of the settlers themselves, froze to death, and (2) a drought, beginning also in 1886 and continuing for almost a decade, created an ever-increasing shortage of water. Farmers who may have survived the cold winter found themselves unable to raise crops be- caused they lacked the irrigation facilities which Powell had so often advocated. The drought forced most of them into bankruptcy, and they had to leave their farms with nothing whatsoever to show for their past efforts. At long last, however, proposals of Powell began to receive serious attention. A Senate resolution was passed February 13, 1888, in which the Secretary of the Interior was requested to report whether he thought the Geo- logical Survey should survey and segregate irrigable public lands, reservoir sites, and canal routes in the arid region. W. F. Vilas, then Secretary of the In- terior (whose home in Madison, Wis., was less than 60 miles from Powell's boyhood home), promptly referred the resolution to Powell. In Wallace Stegner's (1954, p. 300) book "Beyond the Hun- dredth Meridian" the consequences thereof are de- scribed as follows: Major Powell, confronted with an opportunity for which he had waited a full decade, rose to the Secretary's letter like a starving cat to a sardine. The conclusions of his "Arid Region" had not been changed but only aggravated by ten years of [land] settlement. The smaller streams were no longer a consideration because by now they were mainly utilized; if action had been taken years ago, much wasteful development could have been prevented. Now the only course was to concentrate on the larger streams, on reservoirs and storm-water basins, because "utilization of the large streams by owners of small tracts must wait until large numbers of the holders of small tracts can be induced to settle simul- taneously * * * and be further induced to engage in the cor- porate or cooperative enterprise necessary to construct great headworks and canals." On those larger streams, in other words, his cooperative irrigation districts were still possible; a survey could still be made ahead of any extensive settle- ment to avoid complication by squatter's rights and vested interests. CAMP EMBUDO 5 On March 20, 1888, a subsequent joint resolution was passed which in effect implemented Powell's original plan. It directed the Secretary of the In- terior to "make an examination of that portion of the United States where agriculture is carried on by means of irrigation, as to the natural advantages for the storage of water for irrigation purposes with the practicability of constructing reservoirs, to- gether with the capacity of streams, and the cost of construction and capacity of reservoirs, and such other facts as bear on the question of storage of water for irrigation purposes." (See Powell, 1889, p. 2; Sterling, 1940, p. 422.) On October 2, 1888, the Sundry Civil Bill went through with an initial appropriation of $100,000 for such work. Powell thereupon became responsible for not only the work performed in the Geological Survey (including some geological work for State surveys) and the Bureau of Ethnology but also for that of an Irrigation Sur- vey-an agency more explosive in its social and political implications than all his other activities combined (Stegner, 1954, p. 304). Great 'authority was accordingly placed in his hands, and perhaps never before was there such a need for prompt action (Stegner, 1962, p. XXII; Davis, 1915, p. 50). In view of that need, Powell placed A. H. Thomp- son, who had made the second trip down the Colo- rado Canyon with him, in charge of the Irrigation Survey's mapping operations and instructed him to. mobilize his triangulation parties in Montana, Nevada, New Mexico, and Colorado, where they would best serve the needs of the new Irrigation Survey. He also withdrew C. E. Dutton from his studies of volcanoes and earthquakes to organize the engineering and hydrometric units of the new Survey. The third and final major innovation was to establish a camp at Embudo, on the Rio Grande in northern New Mexico, to train young engineering school graduates in the art of stream gaging. There were numerous reasons for selecting this seemingly remote site for that camp, namely : 1. Funds made available by Congress to the Irri- gation Survey were intended for use in the arid region; thus all sites east of the 100th meridian were immediately eliminated from consideration. 2. To get the new program under way as soon as possible after October 2 (when the appro- priation bill was passed), weather had to be taken into consideration. Practically all north- ern streams, which would soon be frozen over, had to be eliminated, and only those in the southwest were left for consideration. 446-050 O - 71 - 2 3. Convenient railroad transportation directly to the site was necessary to expedite the project. Besides meeting all those requirements, the Rio Grande at Embudo was of just about the right size for the intended purpose. There were also some problems developing in the valley for which stream- flow records might serve useful purposes. One was a large irrigation dam near Santa Fe that was being talked about. Another had international implica- tions. Farmers in Mexico were becoming uneasy about the amount of water the irrigation farmers in the upper reaches of the river diverted during dry periods, leaving them with an inadequate supply for watering Mexican crops. The selection of Em- budo for that campsite seems, therefore, to have been adequately justified. CAMP EMBUDO So it was that on the 9th of December in 1888 a group of at least eight young engineers, most of whom had recently been graduated from eastern colleges, stepped off a coach of the narrow gage Denver and Rio Grande Railway at Embudo, N. Mex. Only one of them, W. A. Farish, was a west- erner. The others, acquainted almost exclusively with eastern scenery, must have found those sur- roundings strange indeed. Embudo is a Spanish word meaning "funnel," and that name was well chosen for this area. Here the cactus-and-pifion clad foothills of the San Juan Mountains toward the west and of the Culebra Range of the Rocky Mountains toward the east converge to form a gigantic funnel through which the Rio Grande continually dis- charges its contents. These young engineers represented perhaps the first persons to have been employed in the new Irrigation Survey under Maj. John Wesley Powell. Between Major Powell and his assistant, C. E. Dutton, (an Army captain on detail from the Ord- nance Corp), it had been decided that the new Bu- reau should consist of two main divisions-a Topo- graphic Survey and a Hydraulic Survey-and that the Hydraulic Survey should be divided into an Engineering Branch and a Hydrographic Branch. While there was at the time a plentiful supply of good topographers and capable irrigation engineers for staffing some-of those units, the problem of find- ing suitable employees to staff the Hydrographic Branch was quite a different matter. Captain Dutton (in Powell, 1889, p. 79) explained it as follows : In view of the novelty of the work thus involved upon the survey, of the impossibility of finding men skilled in the work 6 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING FIGURE 2.-Topography at Embudo, N. Mex. Surveyed in 1889 by L. D. Hopson and W. P. Troeridge, Jr. 1, Can required, of want of instruments adapted to the work, and in further view of the fact that the winter was near at hand, during which the fieldwork would, in most portions of the West, be impracticable, it was deemed best to select a small body of men of good education and high general intelligence and establish them at some advantageous station where they could, in the course of the winter months, acquire a knowl- edge of the methods and instruments they would have to employ. Fourteen young men were carefully selected and were placed in a camp of instruction, situated at Embudo on the Rio Grande River, about 50 miles north of Santa Fe, in New Mexico, where they passed the winter in praclicing with the various instruments selected for trial and in‘Lbecomin‘g familiar with the theory and practical application of the methods. In the month of April the camp was broken up and the men distributed to their respective fields of work. The camp of instruction at Embudo was placed in charge of Mr. F. H. Newell, and the work required of the men con- sisted in practicing stream gauging by various methods, measuring the rise and fall of the stream from day to day, measuring the daily evaporation, and making observations with meteorological instruments. CAMP EMBUDO 7T i0 2130 400 ec|>o oq y Contour interval, 10 feet aim Photographs of the three top officials of this new Irrigation Survey-John Wesley Powell, Clarence Edward Dutton, and Frederick Haynes Newell- are presented in figures 1, 19, and 20, respectively. It is true that some western States, California and Colorado in particular, had previously engaged in stream gaging operations of their own, but W. H. Hall, who directed the work in California, and E. S. Nettleton, who directed similar work in Colo- 000 feet ] imbudo training center for Irrigation Survey hydrographers. 2, Location of 1889 gage. 3, Location of gage in 1969. rado, soon became members of the Engineering Branch of the Irrigation Survey, where their pre- vious experience and special talents were of great, value. . No mention of it could be found in the surviving records, but it seems very likely that the group of young engineers, including P. H. Christie and F. H. Newell (who arrived at Embudo before the others), spent their first night or two in the tiny railroad 8 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING station because there were very few other suitable buildings in the area. But on December 10, 1888 (the day following their arrival), a supply of tents, purchased from the Army especially for their use, and a supply of folding cots arrived. The campsite, which Newell and Christie had probably selected while waiting for the others to arrive, was in a sheltered spot among the hills of the landward side of the railroad tracks about 0.6 mile upstream from the station. Its location is shown in figure 2, which is a partly reconstructed topographic map surveyed in 1889 by two of the students, L. D. Hopson and W. P. Trowbridge, Jr. The next order of business for the group was to clear the campsite and to set up the tents. And since those tents showed promise of affording the men better sleeping quarters than they had during the previous nights, the job must have been tackled with considerable alacrity. But that promise failed to materialize. With Embudo's elevation being over 5,800 feet, the winter temperatures, especially at night, turned out to be much colder than was an- ticipated. In an effort to adjust to this new prob- lem, most of the men abandoned their cots and slept in blankets in shallow trenches dug into the dirt floors of their tents. A few of the more enter- prising members even excavated a cave into a side hill, where they slept in relative comfort until the camp goat fell through the chimney and "wrecked things generally." A higher and stronger chimney was subsequently installed, and the cave was re- occupied (Follansbee, 1939, p. 47). A contemporary photograph of the camp is shown in figure 3, and a f recent photograph of the same area, in figure 4. Camp personnel Soon after that first group of engineers finished erecting the tents, four more candidates for in- struction arrived. A final one came during the following March. Prof. G. E. Curtis of Washburn College, Topeka, Kans. (who had formerly been with the U.S. Signal Service), also arrived. He was employed to instruct the men in the care and use of meteorological instruments. A cook, two laborers, and a packer rounded out the quota of 21 permanent members of the group. A list of their names follows : . F. H. Newell (in charge) . Prof. G. E. Curtis (instructor) . T. M. Bannon . P. H. Christie (topographer and disbursing officer) . H. M. Dyar (who arrived in March 1889) . W. A. Farish . Frank Harrison > O0 ho i = O of 8. L. D. Hopson (who helped survey map shown in fig. 2) 9. R. P. Irving 10. L. B. Kendall 11. A. C. Lane 12. J. W. Mitchell 13. G. T. Quinby 14. Robert Robertson 15. R. S. Tarr 16. W. P. Trowbridge, Jr. (who also helped survey map in fig. 2) 17. J. B. Williams 18. Frank Fisher (laborer) 19. Juan Romero (laborer) 20. Dick Shumway (packer) 21. Charlie Hines (cook) Their monthly salaries ranged from $100 for Newell and Williams to $75 and $50 for the others. No photographs are known to exist in which all 21 members appear together, but two were taken in which about half of them appeared in each. Those photographs, together with their identifications wherever known, are shown in figures 5 and 6. STREAM-GAGING OPERATIONS J. B. Williams, who seems to have had some actual previous experience at stream gaging, selected the site for their first measuring section. There they built themselves a raft, using four empty barrels for floats, and they stretched a rope across the river for holding the raft at the various plages where soundings and velocity measurements were obtained. Except for a statement that this section was located "about one-half a mile upstream from the camp," no closer identification of it has been found. Because no current meters were immediately available, a variety of float measurementskwere the first to be made of the Rio Grande. Later, levels were run alongside the river to ascertain its slope, and formulas were used for computing the discharge. Each day a different student was appointed to gather meteorological data such as readings of the barometer every hour, twice-a-day temperatures of the river water, and readings of the amount of water that had evaporated from the cook's bread pan (which had been commandeered for making such experiments). Early in January 1889 the equipment became more sophisticated. The measuring section was moved downstream to a point opposite the railroad station. A steel cable (rather than a rope) was stretched across the river, and a separate tag line was stretched above it for locating the measuring points. A boat was obtained from which to gather the streamflow data while held in place by ropes STREAM-GAGING OPERATIONS 9 FIGURE 3.-Camp Embudo, N. Mex. (1888-89). FIGURE 4.-Embudo campsite (1969). 446-050 O - 71 - 3 10 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING L. S. Kendall W. P. Trowbridge, Jr. Prof. George E. Curtis . T. M. Bannon . F. H. Newell . George T. Quinby . Robert Robertson . R.S. Tarr . R. P. Irving 10. Dick Shumway (packer) 11. J. W. Mitchell 12. W. A. Farish t 00 1C; Ot i> C Io i- FIGURE 5.-Student hydrographers at Embudo. STREAM-GAGING OPERATIONS 11 FIGURE 6.-Student hydrographers at Embudo. Note: The numbered individuals are believed to be the persons bearing those same numbers in figure 5. from the cable. A recording gage "of the horizontal- cylinder type, similar to the tide gages used by the Coast and Geodetic Survey" was placed in operation for a short time about 75 feet upstream from the cable. It would probably have been of the type originally designed in 1845 by Joseph Saxton (later a member of the Natl. Acad. of Sci.) while he was in charge of the Office of Weights and Measures. Drawings and a photograph of such a recorder ap- pear in figures 7 and 8 respectively. When it was installed, a slope gage was constructed directly over the intake pipe leading from the river to the re- corder's stilling well. Its landward end seems to have been anchored by the planks which surrounded that well. Figure 9 presents a photograph of some of those new stream gaging facilities. In it the recording gage shelter and the slope gage appear together along the shore toward the right, and the cableway, with the boat resting behind it, toward the left. At 12 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING DRAWING OF THE SELE-REGISTERING TIDE GAUGE pEvisE» ny JOSEPH SAXTON For the use of the U.S. Coast Survey Scale It inches tol foot 1853 Horizontal Plan Rear Elevation FIGURE 7.-Drawings of Saxton's tide gage. the time this photograph was taken (about 1889), the railroad station did not have the veneer of cobblestones it now has. That veneer was added to it after 1912 by Henry Wallace, a new station agent who arrived at Embudo about that time, as shown in figure 10. The railroad, incidently, was abandoned in this area in 1941. The "Albuquerque Journal" reported that 55 miles of tracks had been "lifted" to be sent to China for use on the Burma Road. Other sources indicate that some of the locomotives were sold to the U.S. Army in 1942 and sent to the Yukon for use on the White Pass and Yukon and also that some of the passenger cars may still be seen at the Colorado Railroad Museum at Golden, Colo. But to return to those 1889 innovations at the camp: The bread pan was replaced by a custom- built evaporating pan having floats for allowing it to rest on a pool of water. It was also provided with a built-in precision scale for measuring the amounts of water that had evaporated between observations. Figure 11 presents a drawing, from the "Second Annual Report of the Irrigation Survey" (1889- 1900), of that new evaporating pan. A program of collecting water samples from which to determine the amount of sediment carried by the river was inaugurated soon after facilities arrived for drying and weighing such samples. Studies were even made of the bedload movement. The first paragraph in a notebook presently (1969) STREAM-GAGING OPERATIONS 183 Side Elevation FIGURE 7.-Continued. in the Albuquerque office of the Geological Survey contains the following statement on that subject: Jan. 4, 1889. This investigation was begun with the help of Mr. Mitchell. The object is to determine the volume of the larger pebbles or sand at various points of what is, or what has been river bottom, with the hope of finding the connec- tion between their size and the current velocity by which they were deposited. The bulk of the fieldwork on that project seems to have been done by L. B. Kendall, A. C. Lane, and R. P. Irving in the reach of the Rio Grande just downstream from the wagon bridge shown later in figures 15 and 16. FIGURE 8.-Saxton's tide gage. Photograph supplied by Coast and Geodetic Survey. Their approach to this subject was both mathe- matical and empirical. The notebook contains num- erous references to similar studies made by dis- tinguished earlier investigators and starts off with a formula derived by Sir Archibald Geikie, a friend of John Wesley Powell's. The work shows evidence of having been conducted at a surprisingly high scientific level. The first current meter the group eventually ob- tained was furnished by the U.S. Navy. It was a cable-suspended Haskell Direction-Indicating Meter (U.S. Patent No. 384,362). (See Follansbee, 1939, 14 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING FIGURE 9.-Embudo gaging station on the Rio Grande, N. Mex. (about 1889). FIGURE 10.-Denver and Rio Grande Railway station at Embudo (about 1912). Photograph supplied by State Historical Society of Colorado. STREAM-GAGING OPERATIONS p. 49.) For shallow water, such as occurs at Embudo during winter months, this meter was far too large and much too cumbersome for practical use. Several suggestions were offered in the hope of making it more suitable for use under the existing conditions, and J. B. Williams made numerous trips to an in- strument shop in Denver to obtain a model in which such changes were incorporated. A photograph showing the "before" and "after" designs appears in figure 12. While those changes were under way, another meter-one with rod suspension that was designed several years earlier by E. S. Nettleton for use on Colorado streams-became available. One of them has already been shown at the center of the group in figure 6. It did not require much time for suggestions to be offered for improving Nettleton's meter also. Rec- ords show that on May 16, 1889, Professor Curtis rated an improved model thereof and that, begin- ning July 12 of that same year, G. T. Quinby made a series of three measurements with it of the Rio Grande at San Marcial, some 200 miles or more | downstream from Embudo. The first page of a later measurement at San Marcial is shown in figure 13. 15 FIGURE 11.-Evaporation pan. member of an instrument-making firm in Denver then called Lallie and Bailey, where a considerable number of them were manufactured. It is interest- The improved model of the Nettleton meter was ‘ ing to note that the Nettleton meter has frequently called the Bailey meter, most likely after the junior | been called a Lallie current meter, so that both FIGURE 12.-Haskell current meters. 16 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING DEPARTMENT OF THE |NTERIOR --UNITED STATES GEOLOGICAL SURVEY. Results of Stream Gouging at Station No. Meter No. l s Using M Last rated at By ® {Cree iss On date /o /S’ &f ; Giving Cocfficient .. 7 2447474— lo Rivmugmngc height Width Mean hydraulic radius Fall pm thousand. N.-corf. of roughness. -on: the Meo / ho me‘uw ¢. -f. ft. fl‘yfiar’f Calculated, discharge Ac see. f1. Measured see. ft. Hyd rographer. 011813!“ ATIO‘IS Depth |___ Time in Seconds.. ' "Too itm o noo s aa benet it ; of ob um... | End. _ Diff. . Begin.| End. BECTION. ‘ | Mean , Devth. J Revol. l lln». i por "6m?“ Becon. No. | Width. 3 6. {6 , | pB. aod | _ ~ 94: i I . ./b] _.] Fo" 143 16 KY. £3 _i 144 l. 3 m5 dof 34 + 3 bit £45 Pud Shy 1 SM 11.0 1.9 12.8 a k/ g 69 412.7 6 3,7 ] 44, ]J1if |f ] 47 33.9 $3» 9 ¢4 b+. .[ dF 1M . Ax b.0° [ 63" 7.6 443 Ra) A4 j.0 ,4 | b ub 21 ¢ aA .A f 1,4 1647 tut—3M _dLf ' bee B1 %b bt - bo 3 14 .rt. 4 0 f T4 ILY Ff ./ f6 14 17.0 bl 1405 {7 .} {0 : Jutsw [3 df | i ': fud mulet h., | j [l. sf dq t48" o. [66 17 I JP | .be, #1» Sh B 6d ,( 68" 3f 3 a J'Oi/Jd- L1 0; baad f- < | | | $0. If -q rt? s ~ » op ~ € we? 48) j A | 1 i f i l ¢ } | i ¥ 6 “$7; eran eate. 3 figs prgs a> 4 $ FJ Coefficient. 34+ 48 | Velocity | - Aren I Discharee pee |? 0 loot: )| ot Second. - Section, (- Section. NOTES, o Lo spe gr pas iff 91 be? Ait $# %f" 227 FIGURE 13.-Discharge measurement notes, Rio Grande at San Marcial, N. Mex., August 8, 1889. members of that firm have had meters named after them. That firm, however, was not the exclusive manufacturer of the Nettleton-type meters. An instrument maker named W. E. Scott, also of Den- ver, built several of the earlier models. Figure 144 shows one of the Nettleton meters as built by Scott, and figure 14B shows one of the improved "Bailey" models. The meters shown in both of these photo- graphs are from the Smithsonian Institution's large collection of early current meters. As will be seen, the main difference between them is that in the Bailey meter the counting wheels are located in a glass-covered compartment whereas the wheels of the other are not so enclosed. The purpose of the enclosure was to prevent grasses and other fibrous materials carried in the streams from becoming enmeshed in the gears of those counting wheels. With the advent of these rod-suspended meters, experiments were made in order to determine how velocities could best be measured with them. The following three methods which seemed most attrac- tive have been described essentially as on pages 13 and 14 in the "Second Annual Report of the Irriga- tion Survey" 1. In shallow streams, as are most of the rivers of the arid region, the work can be shortened by what is called integration. Instead of using the meter at various given points in a vertical line, it is moved at a very slow, uniform speed down and up, from top to bottom and back again, to obtain an average of the velocities at all points in the vertical. In this case the river is considered as being divided into a number of inde- pendent narrow streams of equal width, the discharge of each being obtained by multiplying its area into the observed average velocity in its central position; then, by adding these discharges together, the total for the whole river is found. With a little practice the stream gager can raise and lower the meter at a constant rate in any given number of seconds; for example, with water 5 feet deep, starting at the top and going to the STREAM-GAGING OPERATIONS 17 bottom in 20 seconds, then back to the top in 20 seconds more, and repeating three times, making in all, 2 minutes. 2. For measuring the discharge of canals or small streams with nearly level bottoms, the horizontal or diagonal integration method has been occasionally used, obtain- ing at once an average for the whole flow. The meter is carried slowly from side to side horizontally, or it is moved diagonally from the top on one side down on the cross section at an angle of about 45°, then up at about the same angle from the top, then down, continuing in this way until the opposite side is reached. In the same way a return trip is made up and down, crossing the path of the first, the meter cominggout at the top each time over the spot where before it had reached the bottom, and vice versa. 3. In wide, deep rivers, the meter measurements are made at a number of places evenly distributed across the stream, and at each of these places, observations are made of the velocity near the surface, near the bottom, and at various intermediate points, such as 5 to 10 feet | apart in the vertical line. In this way the velocity is obtained at a large number of points symmetrically distributed in the cross section, and the average of all is considered to be the velocity of the whole river, the discharge being obtained by multiplying the total area of the cross section at this point by this average velocity. The present practice of taking two velocity ob- servations to obtain the average in the vertical- one at the two-tenths depth, the other at the eight- tenths depth-did not then receive consideration. In fact, what was probably the first suggestion re- garding that method was made by H. K. Barrows, then an assistant engineer under N. C. Grover, in charge of the Survey's river work in Vermont and New Hampshire. It appeared in an article that Barrows had written for the July 1905 issue of the "Journal of the Association of Engineering Soci- eties." J. C. Hoyt of the Survey subsequently re- ported the general adoption of that method in his article entitled "Recent Changes in the Methods and Equipment in the Water-Resources Work of the United States Geological Survey" that appeared in volume 60 (July-December 1908) of "Engineering News." After the engineers at Camp Embudo had become familiar with the fundamentals of stream gaging, they were sent either singly or in pairs to nearby streams in order that they might gain experience in selecting suitable sites for installing gages and making measurements. In many respects this was also to test their resourcefulness and to find how well the lessons they had received at Embudo had been learned. Between the end of April 1889, when the train- ing period was completed, and the end of the fol- B FIGURE 14.-Nettleton current meters. A, Manufactured by W. E. Scott. B, Redesigned by engineers at Camp Embudo and manufactured by Bailey. Photographs supplied by Smithsonian Institution. lowing July, a little preliminary shuffling of per- sonnel took place, but that ended with 10 of these "students" becoming classified as "Hydrographers" and "Assistant Hydrographers" and their being transferred to the following locations in the arid 18 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING FIGURE 15.-View looking upstream at Embudo at old wagon bridge on which recording and staff gages were in operation 1912-1914. FIGURE 16.-A later view looking downstream and showing, in front of the second locomotive, the new (1914) recording gage shelter. STREAM-GAGING OPERATIONS 19 U. S. GEOLOGICAL SURVEY RIO GRANDE GAGING STATION ESTABLISHED 1889 FIRST GAGING STATION ESTABLISHED BY U. S. GEOLOGICAL SURVEY FIGURE 17.-The present Embudo gaging station. FIGURE 18.-Upstream view of present gaging station. 20 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING region with specific instructions as to how to carry out their parts in the Irrigation Survey program: Arkansas River basin ...... Robert Robertson and R. P. Irving Upper Rio Grande basin ...G. T. Quinby Rio Grande at El Paso .... H. M. Dyar Gila River basin ...... W. A. Farish Truckee-Carson River l W. P. Trowbridge, Jr. Utah Territory ...... F. H. Newell and T. M. Bannon Snake River basin ...... L. D. Hopson Upper Missouri River DAB 2. J. B. Williams Among the remaining engineers, one had left camp before completing the course, another was ready to resign, and the third claimed that he did not care to spend the rest of his life "jiggling a meter." One feature that was not changed by this exodus was the gaging station itself. The station agent of the railroad, C. L. Pollard, was employed to read the gage, and the discharge records at Embudo were not then interrupted, although beginning in 1904 they were discontinued for several years. When they were resumed in 1912, with a new station agent, Henry Wallace, as the observer, a recording gage and a vertical staff gage were installed on a pier of the Santa Barbara Tie and Pole Co.'s old wagon bridge as shown in figure 15. Two years later, when the bridge became unsafe for that pur- pose, the gaging station was moved somewhat less than 200 feet farther downstream to its present location on the right bank of the Rio Grande. A con- crete well and gage shelter were constructed there along with a cableway from which to obtain stream- flow measurements during high-water periods. Both the old and new locations appear in figure 16. The gage observer, Mr. Wallace, has been previously mentioned as having been the man who veneered the railroad station with cobblestones. Inasmuch as he has been reported as having applied such stone fac- ings onto "every object in the vicinity that would hold still," he might very well have had a hand in applying the same kind of a facing onto the new recording gage shelter. Beginning in 1915, and continuing until 1931, the gaging station was operated by the State of New Mexico, but as of July 1, 1931, the Geological Sur- vey resumed the responsibility for its operation under a cooperative agreement with the State. It has been in continuous operation ever since. Several major improvements were undertaken at the sta- tion during the fall of 1941. The overall height of the well was increased by about 7 feet, and a heavy retaining wall was constructed to protect the instal- lation. The old shelter was made use of as part of the new well, and a new shelter was added on top of it. As before, the shelter was veneered with cob- blestones to match the railroad station. The old roof was re-used for covering the new shelter. It was made of tile for protection against fires which could have been produced by sparks from the Denver and Rio Grande Railway locomotives which passed close by-a menace that continued until only a few months thereafter, when the operation of the rail- road was discontinued. In contrast to the previous arrangement wherein the door of the shelter was located at the upstream side, the new door was placed in the landward side of the house. Travelers who now pass through Embudo on Highway 64 between Espanola and Taos, N. Mex., have a fine view of that attractive gaging station. Close to the A-frame on the left bank of the river is a neat historical marker. Photographs of the sta- tion and marker appear in figures 17 and 18. With the "graduation" of those student hydrog- raphers from this training camp at Embudo, a high point was attained in the short life of the Irrigation Survey. The occasion also coincided with the zenith of the fabulous career of John Wesley Powell, the creator and topmost official of that Survey. EPILOG Despite the remarkable progress that was subse- quently made by these young engineers, the Hydro- graphic Branch of the Irrigation Survey did not last very long, and its final days were marked with sev- eral tragedies. H. M. Dyar, who among his other duties kept the Embudo gaging station in opera- tion, had to resign because of ill health. L. D. Hopson, who had helped survey the map shown in figure 2 and who had been detailed to the Snake River basin, was drowned. Finally (on August 22, 1890), an impending curtailment of funds made it necessary for F. H. Newell to advise all the men in the Engineering and Hydrographic Branches to turn over all their equipment, mules, and horses to the néarest topographic field office and to discon- tinue their official activities (Follansbee, 1939, p. 64). A few of the men, including Newell, were assigned to other duties in the Geological Survey. Others sought employment elsewhere. Shortly there- after, J. B. Williams committed suicide (Follansbee, 1939, p. 65). With regard to Powell himself, the tribulations he then had to endure were, in a per- sonal way, tragic also. As previously indicated, John Wesley Powell re- fused to subscribe to the Utopian claims that were EPILOG 21 being used as inducements for farmers to settle in the arid region. While prospective settlers were assured that practically all of the land in that region was suitable for farming without irrigation and that once they had plowed their land, "rain would fol- low the plow," Powell kept insisting that only 1 to 3 percent of such land could be farmed profitably (Darrah, 1951, p. 222). Even then, Powell main- tained that irrigation facilities would have to be provided and that the remaining area should be applied, where suitable, to forests and grazing. The differences between these conflicting views became more acute when both President Cleveland FIGURE 19.-Clarence Edward Dutton (1841-1912). and the Attorney General agreed with Powell's interpretation of proposed legislation related to irri- gation. Under that interpretation, Powell would have authority to prevent the entry of homesteaders onto any of the remaining lands of the entire public domain in the arid region until the topographic maps were completed, the hydrographic studies made, the plans for the dams and canals formulated, and as many 80-acre farms were laid out on the map as the volume of available water could sup- port-an undertaking that would obviously require considerable time. Opponents of the Powell point of view insisted "We want crops. We do not want pic- tures, and the Major is making pictures." (See Sterling, 1940, p. 430.) Impatient with anything that tended to delay the movement of settlers into the West, consideration was given to getting the Irrigation Survey trans- ferred to the Department of Agriculture. Being un- certain, however, as to whether that could be achieved in the face of Powell's eminent reputation, the decision was made that the best course was to , repeal the entire act and to return to the "status quo ante." (See Sterling, 1940, p. 431.) The House Appropriations Committee was told "Every repre- sentative of the arid region would prefer there would be no appropriation to having it continued under Major Powell." (See Sterling, 1940, p. 431.) To that end, opponents of the activities finally de- manded and received approval for a Senate investi- gation to be held on this subject. The hearings lasted from January 17 to March 28, 1890. They are given in Senate Report 928, part 5, 51st Congress, 1st session (Serial No. 2708, p. 5-229). Perhaps the most damaging testimony against Powell was that which related to his handling of the mapping pro- gram. He had declared repeatedly that without good topographic maps, the Irrigation Survey could not be carried out in a complete and orderly fashion. It was revealed during the hearings that out of the first $100,000 allotted for irrigation investigations, at least $60,000 had been applied to mapping opera- tions. Moreover, he had also used funds which Con- gress had appropriated for the regular mapping program of the Geological Survey to help speed up the production of the arid-region maps. Nothing in the legislation prohibited him from doing so, but several witnesses were called to the stand in an effort to establish that such action constituted an improper use of public funds. One of those witnesses was Powell's administra- tive assistant, C. E. Dutton (fig. 19). Dutton was 22 EMBUDO, NEW MEXICO, BIRTHPLACE OF SYSTEMATIC STREAM GAGING FIGURE 20.-Frederick Haynes Newell (1862-1932). asked, "Is there any connection, in practical opera- tions between the topographic work and the engi- neering work; how do they cooperate if at all?" He replied in part (U.S. Congress, Special Senate Com- mittee, 1890, p. 133) : According to my understanding, there is no absolute depend- ence upon topographic work for the proper conduct of good engineering and hydrographic work; in other words, an engi- neering and hydrographic survey could be conducted with good results, meeting the purpose and requirements of the law, if there were no topographic survey. Some Congressmen agreed with Dutton, and some disagreed, but these hearings caused a sharp decline to occur in the popularity which Powell had previ- ously enjoyed. Soon thereafter the goals of the western Congressmen were achieved in a manner that would impede Powell's progress the most, namely through the pocketbook. They had put through an amendment to the Sundry Civil Appro- priations Bill (signed August 30, 1890) which had the effect of reducing the $720,000 that Powell had requested for continuing the Irrigation Survey work to only $162,500. And that amount was made avail- able for use only on mapping operations west of the 101st meridian. Powell was accordingly forced to discontinue the engineering and hydrographic sec- tions of the Irrigation Survey, and Newell, as pre- viously mentioned, had to notify the field engineers. According to Sterling, this whole controversy led to Powell's resignation in May 1894 as Director of the Geological Survey (after he became sure that a competent successor, C. D. Walcott, would be selected to carry on the work). He felt that Con- gress had lost confidence in him (Sterling, 1940, p. 433). He died at "Haven" in Hancock County, Maine, September 23, 1902. Soon after the Senate hearings were over, Dutton (then a major) was relieved of his duties with the Irrigation Survey. An order issued by the War De- partment directed him to report to the Ordnance Office as of July 23, 1890. In a footnote in Stegner's "Beyond the Hundredth Meridian," it is contended that "his testimony before the Committee, and his disagreement with Powell on the propriety of con- centrating funds from both appropriations on top- ography led him to return to regular Army duty." (See Stegner, 1954, p. 414.) He died in Englewood, N.J., January 4, 1912. With regard to Newell, he was transferred to the Topographic Branch of the Geological Survey, but any stream-gaging problems that came within the purview of the Bureau were referred to him. Soon after Walcott became the new Director, he informed Newell that he found nothing in the legislation which would justify continuing such work. Newell thereupon persuaded Senator W. V. Allen of Nebraska to offer an amendment to a pending Sundry Civil Appropriations Act (Follansbee, 1939, p. 70) . It called for the Geological Survey to engage in stream-gaging operations, with no restrictions as to where in the United States such work should be performed. The amendment passed, but not until the small original allotment of $25,000 was reduced to a mere $12,500. Nevertheless, that allotment became available as of August 18, 1894, and since that time, funds have continued to be appropriated regularly for that purpose. F. H. Newell (fig. 20) was its first "Hydrographer in Charge," but in 1907, when the Reclamation Service became separated from the Geological Survey, he was selected as that new Bureau's first Director. He died on July 5, 19832. The pioneer work he performed in those early years in the Geological Survey has led to his having often been referred to as the "father of systematic stream gaging" in this country. Among the many honors REFERENCES 283 he received was the Cullum Geographical Medal in 1918 (McDaniel, 1933) on which was inscribed : He carried water from a mountain wilderness to turn the waste places of the desert into homes for freemen. President Theodore Roosevelt was among those who publicly expressed high praise for his work (McDaniel, 1933, p 1598). The list of scientific and engineering societies in which he held mem- berships and actively participated is far too long to be presented here, but the facts that he was Secretary of the National Geographic Society and served on its Board of Managers for several years, that he also served as Secretary of the American Forestry Association for several years, and that it was he who called the first conference which led to the formation of the American Association of Engi- neers (now defunct, but which had many precepts similar to those of the present National Society of Professional Engineers) and served as its President in 1919 are indications of the variety of his inter- ests and of the extent to which he participated in scientific and engineering activities. From three historical points of view, therefore, the training camp for hydrographers on the Rio Grande at the tiny village of Embudo, N. Mex., de- serves the attention of hydraulic engineers every- where. It was the site of the first stream-gaging operations of the U.S. Geological Survey; it was authorized by John Wesley Powell at the time when his eminence had arrived at its peak ; and it was the starting point of the outstanding career of the camp's - engineer-in-charge, - Frederick _ Haynes Newell. REFERENCES Darrah, W. C., 1951, Powell of the Colorado: Princeton, Mass., 426 p. Davis, W. M., 1915, Biographical memoir of John Wesley Powell, 1834-1902: [U.S.] Natl. Acad. Sci. Biog. Mem., v. 8, 83 p., Washington, D.C. Follansbee, Robert, 1939, A history of the Water Resources Branch of the United States Geological Survey to June 30, 1919: Washington, D.C., 459 p. McDaniel, A. B., 1933, Frederick Haynes Newell, M. Am. Soc. C. E., died July 5, 1982: Am. Soc. Civil Engineers Proc., October, p. 1597-1600. Marsh, 0. C., 1878, Letter dated November 26, 1878: U.S. 45th Cong., 3d sess., House Misc. Doc. 5, serial 1861, p. 2. Powell, J. W., 1889, Irrigation: U.S. Geol. Survey 10th Ann. Rept., pt. 2, 123 p. Stegner, W. E., 1954, Beyond the hundredth meridian-John Wesley Powell and the second opening of the West: Boston, 438 p. Stegner, W. E., ed., 1962, Report on the lands of the arid region of the United States, by John Wesley Powell: Cambridge, Mass., 202 p. Sterling, E. W., 1940, The Powell Irrigation Survey, 1888- 1893: Mississippi Valley Hist. Rev., v. 27, no. 3, p. 421- 434. U.S. Congress, Special Senate Committee, 1890, Report on the irrigation and reclamation of the arid lands: U.S. 51st Cong., 1st sess., Rept. 928, pt. 5, serial 2708, p. 133. THE CULLUM GEOGRAPHICAL MEDAL AWARDED TO FREDERICK HAYNES NEWELL U. S, GOVERNMENT PRINTING OFFICE : 1971 O - 446-050 ory of the _ Water Supply for - The bomstoc red in cooperation with the Nevada State Department of Conservation and Natural Resources E CALIFORNIA EOLOGICAL SURVEY PROFESSIONAL PAPER 779 The Story of the Water Supply for the Comstock Virginia City probably in the late 1870's. Courtesy of Nevada Historical Society. THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK Including the Towns of Virginia City, Gold Hill, and Silver City, Nevada Together With Other Water-Related Events For the Period 1859-1969 HUGH A. SHAMBERGER Prepared in cooperation with the Nevada State Department of Conservation and Natural Resources GEOLOGICAL SURVEY PROFESSIONAL PAXPER - 7 79 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress catalog-card No. 70-179642 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON. :: 197: For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 70 cents (paper cover) Stock Number 2401-1157 ACKNOWLEDGMENTS I am grateful to the many fine friends who gave me much needed assistance in putting this story together. I depended a great deal on Harry E. (Red) McGovern, Water Master of the Sierra Water System, and am indebted to him and to Hobart Leonard, President and Superintendent of the Virginia City Water Company, for their fine cooperation. The personnel of the Nevada Historical Society were most helpful, as were those of the Nevada State Library, the University of Nevada Library, the Ormsby County Library, and the Mackay School of Mines Library. For making the reproduction copy of the Buck and Schussler letters, as well as other material, I am indebted to the late Jack McCarthy, State Printer, and his assistant Tom Carter, now Acting State Printer. For some of the engineering details, I want to acknowledge the assistance of Walter Reid, P.E., of Virginia City. On the matter of editing, I needed considerable help. I was fortunate to have the advice of Victor O. Goodwin, well-recognized writer of Nevada his- tory. I also received help from my daughter, Mrs. Roy (Ann) Callahan, my son Allan, and my wife Ethel. Some of the old timers in Washoe Valley who fur- nished information were Henry Heidenreich, Bill Pedroli, and Norman and Don Cliff. I want to especially acknowledge the work of Ethel Murphy, of the De- partment of Conservation and Natural Resources, in typing this story, as well as other personnel in that office. The writing of this story has been done under the auspices of the U.S. Geological Survey and the Nevada Department of Conservation and Natural Resources. I am appreciative of the counsel and guidance given me by George Worts, District Chief, U.S. Geological Survey, and his assistant Thomas Eakin, and by Elmo DeRicco, Director of the Department of Conservation and Natural Resources, and his assistant Norman Hall. The list of all those who gave me assistance is too long to include here, but I want them to know I am most appreciative. Huon A. October 1969 popremusncne PREFACE After spending nearly 34 years in State service, mostly in the field of water and related resources, I have retired from the daily grind of full-time work. From 1935 to 1957, I served in the Office of State Engineer; from 1957 to 1965, as Director of the Department of Conservation and Natural Resources; and then 244 years as Director of the Center for Water Resources Research of the Desert Research Institute. Like so many professional men who retire, I wanted to spend a part of my time in work that would be both interesting and productive. One day when I was visiting George (Skip) Worts and Thomas Eakin of the U.S. Geological Survey here in Carson City, the discussion got started about the water supplies for the old mining camps of Nevada. It was recognized that very little attention had been given to this particular subject of water supply, with the possible exception of Virginia City. Mr. Worts suggested that I might wish to try my hand on a part-time basis under the Federal-State cooperative program between the U.S. Geological Survey and the Department of Conservation and Natural Resources. Since I have always been interested in our State's history, I lost no time in getting started. My first effort was on the water supply of the Comstock, bringing its history up to 1969, which is covered herein. Since starting the Comstock water-supply story, I have been working on the history of other of the old mining camps and their quest for water. I am finding it exceedingly interesting, and in time I am hopeful that I can cover most of the old mining camps in Nevada, especially those where an adequate source of water for the townsite and mills was not readily available, which generally was the case. Hugen A. Smamerrorr Research Hydrologist U.S. Geological Survey October 1969 VII 428-017 O - 71 - 2 CONTENTS Page, Acknowledgments.. dcf Lenin l el. seee V Prpface. :.... nn enone cement A Ba c eL e r era n cala an ae VII Statistical Summary:... no.". l_ Imola allele ber -n na teens an XT Barly >_... nere nl ec nol. a 1 The Hartly Strugeledfor : Water:........l ; ..to. 8 The First . .slcs ce eel ge coca ene e ns 16 The Second Pipeline... a_ 22 'The Thud Pipeline. nc n 28 Recapitulation of Water Works, __... 30 Water-Related Events, = s 30 The Sierra Nevada Wood and Lumber 30 The Butro tc { .s 31 Water Power and -Blectric _. ....l.l..l.lec0l... S7 Rlectric Hights ._ csc rc _c le dell lled tinal 38 Pumpimg Water From Deep Shafts. _._.._....._......__.l...l.l._ 39 "The Century 42 Curtis-Wright Corporation. _...__l... f... 43 Franktown Irrigation 44 Purchase of Sierra Water System by the State. 45 Conclusions ._. dal nal. li e ci ie deanna can' an 46 Notesand ln vee ber esd ~. 49 .c. ane" mo t n .in ender ane. na 51 ILLUSTRATIONS [Photographs where no credit is given were taken by the author] FrontisprEcE. Virginia City probably in the late 1870's. Page FicurEs - 1-4. Photographs showing: 1. Red House and diversion dam about 1928... 17 2. The Tanks, 1969. Inlet to pressure pipeline... 37 3. Outlet end of inverted siphon, 1969. #7 4. Old flume between Five Mile Reservoir and Virginia City and the pipe replacement. Shown is Hobart Leonard, President, Vir- ginia City WaterCompany:._..._..____. 17 5. Profile of siphon and location of air and blow-off valves. 19 6-8. Photographs showing: 6. Section of first pipe laid in 1878......_.._..__. _. 20 7. Section of 1873 pipeline still in place.... ...... 20 8. Herman Schussler, Consulting Engineer _ __ ___ 21 9. General map of the water-works system of the Virginia and Gold Hill Water Co., 1918......_..._._.._._ 24 IX FicurEs 10-19. Photo 10 11 12. 13. 14. 15. 16. 17: 18. 19. CONTENTS graphs showing: . The screw-joint pipe used in the second pipe- line: I875 72:02:03.1. a emerge - Ale . Five Mile Reservoir; 19690-..;.............. West portal of tunnel through the Sierra divide, 1968: __.: ni Marictte Lake, Concrete block used to anchor pipelines.... Sections of the 1873 and 1887 pipes and method ofiwrepair.._... .s ol lc Hobart Creek Reservoir about 1928-----.__.-. Captain J. B. Overton, Superintendent, Vir- ginia and Gold Hill Water Company-. 'The white house at Lakeview Mules used in the construction of the Sutro £ 20... Map of the town of 21-26. Photo 21 22. 283 24. 25. 26. graphs showing: ; Sutro's mansion - "L-t>_.2 _ Adolph ich. . . Cornish Pump installed at the Union shaft in 1870. .. l...: =+ aas cesar s James M. Leonard, Superintendent of Virginia and Gold Hill Water Company from 1906 10 III era t e an ak Harry E. "Red" McGovern, of the Sierra ssa. Signing of the agreement to purchase the Sierra water system between the State and Marlette Lake Company, June 12, 1963.- Page 26 26 26 27 27 28 29 29 29 34 35 36 37 41 42 43 46 STATISTICAL SUMMARY Virginia City, Gold Hill (Comstock District) and Silver City Discovery of. ore at Virginia City *'*__.-:-.____.L__.. 1859. Virginia & Truckee Railroad "-_.._....__-__-_____ Completed Carson City to Gold Hill, Dec. 21, 1869. Completed Carson City to - Virginia - City, Jan. 29, 1870. Completed Reno to Car- son City, Aug. 24, 1872. Completed Carson City to Minden, Aug. 1, 1906. Sutro .s... gl _c L_ Xuan Llc Started Oct. 19, 1869 and completed July 8, 1878. Pipelines from the Sierra Nevada to Virginia City : * Furst pipelines.... slc ses ll Completed August 1878. Second Completed 1875. Third pipeline.. cee Completed 1887. Mineral Production, 1859-1921 $386,346,931. Siver l _ a $222, 315, 814 Goll _ _c l.. 164, 023, 917 Copper and lead..........._... T, 200 Mineral production, 1850-1057 ... $393,963,725. Peak years of production, 1862-80, approx________ $296,400,000. Peak population, Storey County (Virginia City, Gold' hil)" sL. 14,598. Population, 1960 Census, Storey County__________ 568. Present population, Storey County_____.__________ 606.8 Life of towns: Virgims ca cll 1859 to present. Gold Hill===» c. lll. c malo l_ _l__L2 Do. Silver City (Lyon County).........___._____ Do. *See numbered footnotes at end of text. - : s mew THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK (Virginia City, Gold Hill, and Silver City, Nevada, 1859-1969) EARLY HISTORY Of all the mining towns in Nevada, more has been written about Virginia City than any of the others. When Virginia City is spoken of, Gold Hill, which is located south of Virginia City in Gold Canyon, must be included, since the Comstock Lode extended to Gold Hill. Silver City, which is a few miles farther down Gold Canyon in Lyon County, was actually settled be- fore Virginia City and was a place of considerable im- portance in 1860. In the early days the mines of Silver City rivaled those of Virginia City, but no bonanzas were ever developed in Silver City.®* Virginia City became famous and has remained fa- mous for many reasons. Probably foremost is the fact that it was the greatest producer of silver and gold high-grade ore in history. The recorded production of the Comstock district to 1957 was $393,963,725 in silver and gold,"" the silver portion being about 58 percent of the total. This production figure was probably greatly exceeded, as there was a large unrecorded production in the early days. Another reason for Virginia City's fame is the large number of people who were associated with the development of the Comstock who later became famous; men such as John W. Mackay, James G. Fair, Adolph Sutro, Samuel L. Clemens (Mark Twain), James C. Flood, W. S. O'Brien, William Sharon, D. O. Mills, and H. M. Yerington, to name only a few. While Virginia City and the Comstock Lode were famous in their own right, especially throughout the West, they have gained worldwide notice during the past decade as the result of the "Cartwright family" in the National Broadcasting Company television series "Bonanza." The locale of "Bonanza" is, of course, Vir- ginia City, and the "Ponderosa Ranch" is supposedly near Lake Tahoe. The episodes shown on television are, like most television series, imaginary; yet the locale is real and some of the episodes were developed from *See numbered footnotes at end of text. actual events. A facsimile of Ponderosa Ranch, the make-believe home of the "Cartwrights," was recently constructed at Incline Village on the shores of Lake Tahoe, Nev., and is becoming a great tourist attraction. The Comstock Lode stands alone in the history of Nevada and the early West, in the difficulty of the water problems presented in the extraordinary engineering feats accomplished in order to overcome these problems and to develop the Comstock, and in the ingenuity and courage demonstrated in the undertaking of these projects. The first serious prospecting in the Virginia City- Gold Hill area occurred as early as 1850, and a mining camp existed in Gold Canyon continuously from 1851. The early history of the Comstock is recorded in the following article entitled ketch of Early Times, which appear in the Zerritorial Enterprise on June 20, 1875: In the summer and fall of 1857 there was con- siderable prospecting done for placer mining in the section where lower Gold Hill now stands. It is impossible to give the names of the early pioneers who at that time sought the fickle goddess in these parts. They were generally a wandering adventure- some class, who went where the tidal wave of specu- lation for the time sent them. The next spring a prospecting party was started for the Walker River, which, however, returned during the summer, having met with no success. It was not until early in the year 1859 that prospect- ing between the works at Gold Canyon and the dig- gings which were then worked in the ravine below where the Virginia City Cemetery now stands was carried on to any extent. At that time Mount David- son was known as "Sun Peak" or "Sunrise Peak" because it caught the first rays of the rising sun, and it was a great pity the name was ever changed. At that time John Bishop and Aleck Anderson discovered in what was then known as the right fork of Gold Canyon, a good-looking ledge. "Old Virginny" was told of the find, and this early oracle in mining matters agreed that it might be some- thing good. Comstock, who in that year had a store 1 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK in Carson, Vigneau and others followed. The first pan of dirt went fifteen cents. Water was brought up from the canyon by means of a rough flume built of boards obtained over in Washoe. At that time fifty feet per man was all that the early-established code of the miners allowed a man to claim in one place. The locality was called Gold Hill because it was situated on a little hill just outside of Gold Canyon. It was thus named Febru- ary 8, 1859, and today (1875) the place contains about twelve thousand inhabitants. The flume above-mentioned, in which water was brought to what we shall hereafter designate Gold Hill, was nailed together on the precise point where the Crown Point works now stand. . . . It was the middle of April before the rockers were at work. The first one hundred rockers yielded $5 and a little over. The next day quicksilver, which had been brought from Johntown, was introduced, and $17 were fsic] taken from a single days work of one man. This was not very heavy but it beat the $2, $3, to $5 per day of Gold Canyon so badly that quite an excitement was created by it. Afterwards some averaged $50 and even $100 per day. The first locaters of Gold Hill were John Bishop, Aleck Anderson, "Old Virginny," Vigneau, Com- stock, Camp, Sandy Bowers, Joe Plateau, and one Richards, a renegade Mormon. Immediately after the locations above-mentioned were made {fishop and Camp located the present Yellow Jacket. . . . Then came the building of a log shanty to live in. This was located immediately in front of the Gold Hill croppings. By the 1st of May so many miners had come to the hill that there was neither work or room for them. Several of these started off and located claims all along the Comstock where the City of Virginia now stands. The present Ophir was located at that time by John Jessup. . . . About this time it became necessary to build a large shanty in Gold Hill to accommodate the in- flux of miners. Jessup, of the Ophir, turned in and helped put it up. After it was finished, Jessup and Sides sat down to play a game of cards for drinks. A dispute arose, and Jessup was killed by Sides, who stabbed him twice with a bowie-knife. This was about May 1, 1859. Sides was taken to Eagle Valley (Carson) for trial, but there was never any- thing done with him. Thus the reign of violence inaugurated on the Comstock. . . . After the death of Jessup, and while the majority of the inhabitants of Gold Hill were over in Eagle Valley with his murderer, Reilly and McLaughlin jumped his claim, and have received credit of first discovering the Comstock. The claim was afterwards enlarged by the addi- tion of other claims and had several owners, among whom were Penrod, Comstock, Finny (Old Vir- ginia), Reilly and McLaughlin and was at one time run by Penrod, Comstock & Co. The name was sev- eral times changed 'til at last the name "Ophir" was given it. This is the claim which gave the name of Comstock to the lode. There were several ambi- tions of the honor of standing godfather thereto, but Comstock is the only one who was fortunate enough to achieve immortality in that regard. If the lode had been called after the first discoverer, it should have been named the "Grosch lode," for the brothers located claims for themselves and others thereon long before the days of Virginia City and Gold Hill were known. John L. Newman, who died in the fall of 1861, built the first substantial dwelling ever erected in Virginia City. This was situated on the corner of "A" Street and Sutton Avenue, and constructed in the summer of 1859; but at what time of the sum- mer occupied it is impossible to say. It was not, however, until the second house had been put up at Gold Hill, . . . In the fall of 1859, Virginia City had a popula- tion of between two and three hundred. Their ac- commodations would not be considered first-class today. Many of them slept in the sage brush on the mountain side, for but a small proportion of them could get tents or other lodging accommodations. But there was plenty of timber here then, and their sleeping-rooms were not so desolate and dreary as are the hill-sides now. The winter of 59-60 was a very severe one, and those who could not procure shefler otherwise lived in "holes in the wall," that is, they dug holes in the hillside and used them for dwellings. . .. The first snow fell about the middle of November, and was from a foot and a half to two feet deep. About Christmas a heavy fall was experienced, which covered the ground about five feet deep. . . . The first frame house ever built in this city was erected by James H. Hickman and was located on "A" Street, between Union and Taylor. It was, however, unroofed by a zephyr the following May. The first International Hotel was built on the cor- ner of "B" and Union Streets, of lumber whip- sawed down in Six-Mile Canyon by the men who were the proprietors. John Connell was one of the proprietors and Paul the other. It was erected in the winter of '59 and spring of '60. It was one story high, had a bar-room, dining room, and about a dozen lodging-rooms. The kitchen and din- ing rooms were in the basement. The furniture, as may be surmised, was neither mahogany, rosewood, nor yet walnut, yet the first day it was opened the receipts were $700. It was afterwards (about ©'62) packed in two wagons and moved to Austin where it now stands. In the above news article, mention was made of the settlement of Johntown. Until the writer started his research for this story he does not recall ever having heard of this place, and in all likelihood not too many other people have. Several of the early writers mention it; it was situated in Gold Canyon about 4 miles above Dayton. Its population consisted mostly of Chinese placer miners. From 1856 to 1858 it was described as the "big" mining camp of western Utah Territory, although it never had more than a half-dozen flimsy wooden shacks at any one time." THE EARLY STRUGGLE FOR WATER 3 THE EARLY STRUGGLE FOR WATER Virginia City and the Comstock Lode faced a variety of water problems, which can be considered in three general groups. First, it was necessary to provide an adequate supply of water for the population. Secondly, the operation of the mines required an inordinate amount of water. The final problem was an excess of water in the lower levels of the shafts. Adequate solu- tions were found for the supply for the population and the mines, but the conditions created by the excess amounts of scalding water in the shafts were never overcome and resulted in the discontinuation of deep mining on the Comstock in 1886. Dan DeQuille described the early struggle for water as follows: In the early days, when the first mining was done at Virginia City and Gold Hill, natural springs furnished a supply of water for the use of the few persons then living in the two camps. For a time after the discovery of silver, these springs, and a few wells that were dug by the settlers, sufficed for all uses; as the town grew in population, an in- creased supply of water was demanded. A water company was formed and the water flowing from several tunnels that had been run into the moun- tains west of Virginia City for prospecting pur- poses was collected in large wooden tanks and dis- tributed about the two towns by means of pipes. At length the tunnels from which this supply was ob- tained began to run dry, and a water famine was threatened. It then became necessary to set men to work at extending the tunnels farther into the hills to cut across new strata of rock. This increased the supply for a time, but at length the whole top of the hill into which the tunnels extended ap- peared to be completely drained." Although thousands of dollars had been expended in these various experiments, the danger of water famine constantly confronted the people." Two companies, the Virginia Water Company and the Gold Hill Water Company, had been formed to collect and distribute water. These two companies were consolidated on May 12, 1862, as the Virginia and Gold Hill Water Company." Eliot Lord gave the following description of the efforts of the company to meet the water needs. Before September 1863, they had bought or leased the streams from seven tunnels, the principal water sources, and conducted them through flumes and ditches into large cisterns, from which the water was distributed to all points in Virginia City and Gold Hill. The mains first laid were wooden boxes, roughly joined, and placed on or near the surface, with branch pipes of lead tubing. In Au- gust 1863, iron supply pipes were laid in South C Street and were thenceforth substituted for wood to a considerable extent. If the supply had been commensurate with the demand, the profits of the company would have been extraordinary, but the amount obtained was so scanty that it was neces- sary to dole it out at exhorbitant rates. In October 1863, only 5614 flowing inches (664 gallons per hour) of water could be obtained for the use of Virginia City, 48 of which came from the Santa Rita tunnel alone, and if the stream from the last named tunnel decreased, as appeared probable, a water famine was imminent, (Santa Rita tunnel was located in Ophir Ravine). . . . Fortunately the supply was maintained with slight diminution until the melting of the winter snows refilled the springs. Every succeeding year, as the city grew, the peril of water-drought increased ; every year the record was repeated-flumes and pipes running full in spring and half empty in autumn." The Santa Rita Tunnel was the main water supply for Virginia City until a prospecting adit, known as the Cole Tunnel, encountered a quartz seam on January 7, 1867, that produced 135 inches of water (1,515 gallons per minute). Apparently this quartz seam also supplied the Santa Rita Tunnel water because its flow ceased at once. Following this the Virginia and Gold Hill Water Company leased the water from the Cole Silver Mining Company. This supply was still insufficient, and the water company was forced to supplement their good quality water supply with Virginia City mine water, primarily from the Ophir mine shaft. This caused the people of Virginia City and Gold Hill to complain about the water quality, but the water company very shrewdly encouraged each of the cities to believe that it was the favored one, and that the other was receiving poor quality water. The Cole Company, realizing the value of a pure water supply, refused to renew the water company's lease on the water at the expiration of the old lease in 1870, and immediately began to lay a new system of pipes alongside those of the water company."" The Virginia and Gold Hill Water Company, appar- ently anticipating such a move, commenced the exten- sion of an adit known as the Nevada Tunnel, which would intercept the heretofore noted quartz seam at a point about 30 feet lower than the Cole Tunnel. This work was carried on as rapidly as possible, although it later developed at the hearing before the Ninth Circuit Court, which will be discussed subsequently, that the timing by the water company was such that the quartz seam supplying the water supply would be reached at the time their lease terminated. The Cole Silver Mining Company filed a bill of com- plaint before the Ninth Circuit Court, applying for a preliminary injunction restraining the water company 4 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK from diverting the water until a final hearing. The case was heard before Circuit Judge Sawyer February 13, 1871. The plaintiff alleged that it had discovered and actually appropriated and enjoyed the water for many years. The water had been sold to the defendant, the Virginia and Gold Hill Water Company, by the plaintiff, the Cole Silver Mining Company, and paid for under a lease agreement for several years prior to September 1870. Judge Sawyer, in his opinion, stated that the plaintiff, in excavating a tunnel in a mountain to its mining claim on the public lands of the United States, struck a sub- terranean flow of water, which it appropriated and en- joyed for several years. That the defendant ran a tunnel from a distant point into the mountain, to a point some 30 feet in altitude, directly below the point where the plaintiff obtained the same water; and thereupon the water which flowed through plaintiff's tunnel was intercepted and discharged through defendant's tunnel, and was by it appropriated to its own use. It was held by Judge Sawyer that said diversion and appro- priation of the water was wrongful, and that the com- plainant was entitled to an injunction. It was further stated that the defendant started a tunnel to run to its ledges, commencing lower down the mountain, and at a considerable distance to the south- ward of the entrance to complainant's tunnel. The exca- vation of this tunnel, called the Nevada Tunnel, was prosecuted at times, for several years. Finally, the said defendant entered into a contract to extend the tunnel into the mountain until it should strike a ledge, called the Macey Ledge. The complainant insisted that defendant extended the said tunnel expressly to take its water ; the defend- ant claimed that its objective was to prospect ledges beyond the complainant's claim. A preliminary injune- tion was granted October 6, 1871. Later a motion by the defendant to dissolve the injunction was denied by Circuit Justice Field. Following this ruling, the defendant effectually bulk- headed the Nevada Tunnel, causing the water to once again flow out of the Cole Tunnel. The Cole Company then continued to furnish most of the domestic water to the area, but as the Virginia and Gold Hill Water Company continued to furnish water from the mine shafts to the mills in Gold Canyon exclusively, their revenue exceeded that of the Cole Company. The writer recalls that many years ago he had oc- casion to investigate this source, which was flowing out of an old mining tunnel that was completely caved in. It was known as Cedar Hill Canyon Spring. Later, in 1952, Mr. H. E. Winchester, Division of Water Re- sources, also investigated this source, in connection with the possibility of developing an auxiliary water supply for Virginia City. In his report he stated that the flow of the spring on November 10, 1952, was found to be 39 gallons per minute, which is about 56,000 gallons per day. It had long been evident to the water company that an extraordinary effort was required in order to secure water from some unfailing source; however, according to Eliot Lord, when the plan to conduct water from a Sier‘m creek across Washoe Valley was broached, in the early 1860's, even the boldest speculators were startled." The decision to go to the Sierra Nevada for water was finally reached at a meeting of the directors of the water company held in August 1871. Just recently during a visit to Virginia City, Hobart Leonard, President of the Virginia City Water Com- pany, showed me two letters that certainly have his- torical value and, so far as is known, have never been made public. Mr. Leonard kindly agreed to their use and they are reproduced here in facsimile form. The first one, dated July 14, 1864, addressed to Virginia and Gold Hill Water Company, was from a civil engineer by the name of S. M. Buck. In this letter, it will be noted, Mr. Buck gave an adverse report as to conveying water from the Sierra to Virginia City. The second letter was in the form of a report from Hermann Schussler, addressed to Messrs. Flood and O'Brien, which was dated October 1871, outlining a plan to bring the water from the Sierra Nevada to Virginia City. There are several things of interest in this letter. It was written about 3 months prior to statehood and 9 years prior to the actual construction of the first pipe- line. It must be remembered that at that time no pipeline had ever been laid with a head of as much as 1,000 feet. As Mr. Buck stated near the end of the first paragraph ©. . . to bring water across Washoe Valley at a sufficient height to make it available to supply Virginia City would, to say the least, be one of the most arduous undertakings of engineering and mechanical skill in modern or ancient time." Later in his letter he stated, ©. . 0. it is an undertaking in which no prudent capitalist would ever invest his money ; and I hardly need observe that without capital, and that in great abundance, this undertaking could never be accomplished." It is surmised that the route Mr. Buck had in mind crossed Washoe Valley near its southern end, with the intake in Little Valley about 2 miles north of Red House. His elevations were reasonably accurate, and he stated that his starting point would be about 300 feet above the level of Lake Tahoe, which would make the inlet about 6,520 feet above sea level in elevation. Mr. WaéQ ”7M ffl »A Mef flc WJM Wm? %H@w It 6 %%WMW arri Z é‘f om x. Pa taki... ~I -A te: STS F ana p F 94+ flag; ia 2 a " WM /J/u’ 2. Re ra vsce A - Q Acif m? W0, Wfi mJ-wa %M WM ca ig) Pat 2 L AP I a oe. peces. BY Po 7 swan £94fiuw W553” 6 Wfi Man/MW 47 +2. W dmam‘fiude/ J Lo [eca le: Wfln & é MM“, Mae/c! 7 fflafl flWW W be Ar me m p a ies M A J $22“ W Z %NMWM m“ Wfim W WnW um m ad f- aW/yfaj'w Jaaa $7“ Grete Pn zzféaij/sz/fmué/ 8 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK Buck mentions Alta Lake and Summit Lake. I have found no maps showing these lakes, but I am sure that Summit Lake is now known as Spooner Lake. Perhaps his Alta Lake is what we know as Marlette Lake al- though at the time of his letter it was called Goodwin Lake. Nine years after Mr. Buck's letter, when the pipeline was an actuality, it was considered one of the engineer- ing marvels of all time. Accordingly Mr. Buck should not be condemned for his conservative outlook. It was unlikely that in 1864 any competent engineer would have given a favorable report. However, the need for pure water in large quantities continued, and no more reasonable alternative was dis- covered. More significantly, the powerful combination of Mackay, Fair, Flood, and O'Brien was formed and in March 1869 wrested control of the Hale and Norcross mine from William Sharon. In the same year, they bought Sharon's interest in the Virginia and Gold Hill Water Company, which was subsequently reorganized in 1871. The directors of the new company were Walter S. Dean, W. S. Hobart, John Skae, John W. Mackay, James G. Fair, James C. Flood and W. S. O'Brien. Following the discovery of the Crown Point-Belcher bonanzas in 1870, the new owners of the water company formally decided to go to the Sierra Nevada for water. Mr. Hermann Schussler, a consulting engineer who was also the Chief Engineer of the Spring Valley Water Works of San Francisco, was requested to submit a re- port concerning the feasibility of the project. He com- piled a favorable report and submitted it to Messrs. Flood and O'Brien in October 1871. Mr. Schussler had conducted a survey of the proposed Sutro Tunnel in about 1869, and was no doubt well acquainted with the locale of the area and the water problems confronting the Virginia and Gold Hill Water Company."* A fac- simile of the original report is given here. It would appear that prior to the time of Mr. Schus- sler's report, a tentative route had been decided upon. Dall Creek mentioned in the report as the first source of supply was at that time so named because a Mr. Dall had a lumber mill in Little Valley. Later the name was changed and that portion of the creek above Red House was called Hobart Creek. The portion below Red House was named Franktown Creek. Messrs. Flood and O'Brien, to whom the letter was addressed, as well as those mentioned in the letter-Messrs. Skae, McKay (Mackay), Hobart and Fair-were all directors of the Virginia and Gold Hill Water Company as reorganized in 1871. A portion of the report was devoted to a power scheme which would require a larger pipe alongside the first pipeline to convey a large volume of water to the Gold Hill area, where it could be passed through turbines. While two other pipelines were later installed, they were for an additional water supply to Virginia City and not for the power development as mentioned. In 1887 a power scheme was developed, which will be referred to later. A few months after submitting the aforementioned report, on May 18, 1872, Mr. Schussler submitted the specifications and requisition of iron for the pipe. A month later, June 15, 1872, he submitted the specifica- tions and requisition of rivets for the pipeline. The number of rivets as requisitioned figured out to be 952,900. G zee e pygas.. emrles Cizkee PRasgrs>»" time Ervigie Wza THE EARLY STRUGGLE FOR WATER iew rr. te... . &%/w mpsests ..] Thebes WWW“ gé/Maw7g/«ZZT/7a flaw—W Z. besgin»x Coig 3 flga/Zf‘mflf—S/fiflfi WW/V’fi Lecce WW#@%%W' : flééW/rmfi/WW/W‘ Zz wWW¢Wsz¢ ox, Wyaflm ew cas Yo mers? & --- WW/%W¢g/ C+ aA... W9? wae jprre macmiled Mie Boitzrer o ag aJ cause 2627/37/20? Fa ieme P cs EZ 10 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK | %WWé W/myc,2fé7wé% 1J¢%Wc v5 aP case elev aFe se eof 2C JZ, feo BJ mr fee? Tor Pe,, to Hea) a- arfertle Cer Cc WW eG | wafizxw) o WL PLAR 41W? 7 cGCGzrz > Rozz Who/gm of ese Sea- Wfi [WM a Oez ' er fet Pt I4 5&4; raew ne oem ce M43 Vb” Ife: ceca of yore. bow To Coo Tere, jWhpa/ZéM/ac mm? ery ax. Revtec eff E THE EARLY STRUGGLE FOR WATER 11 - f &, w Fell Liven : /é Reaa bop Pack wrrie bo» AGolrz a) Vo (h. a:¢2&2// My)? e WfiflvflémgfiM/qfi'w ;./f'a %W Irecfees o 25, Rza rer ze pea beep 554/97, fifimm fififiéjfifig harks arre SFR ~ Mééfl/hngfl'Qgg Keser Aue F - 22 B aon Of oars WM -, ones cate ver.. »zce= s 5:4?Wé4fc4/wfl’mwks #. WW fee Toe prizze, . \ wwMMm » Air eroare Pics | RF sais: " 12 x THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK | 1W%W5WMW/4WZ Fo repreints r mere bee ize Crea" Cocoa, de - WMWM/m prom ars se aley /. bhai feeemee. bag. |abgzeet 4 Ireztee ree » f zeg aKa Cacsl eCcee the rrfee ested cK, //7 % fs ¢ frei [dings WW 2g Ps waWWf’Mz‘ MWMWe/WWWB ’/7mwbé7 f bert 2239 23 yo) Ceeohtle » Po 4s W9 B ifo PecYize Km se- CeaCezsscc THE EARLY STRUGGLE FOR WATER I& Ge pepelCome » RReere s, porcieco MW) y@f)h¢%/¢M«Q ore.. 43 po Secgie Z/Q/MQW% aéaJ/n'fllfi/fffl/mzfléfi7 4 «$- aree a¥ Ple Gop, IFE AW bae Eo __ . f» Avs: I | eer mesiCe Io be cf 3 Com z oy [Fk pc yee m:% WMée [3 _ tes. Mg s %W%WWM | eV pame Ao UeCiéiver fevice FPee ceasecenss>> fiWWWJ/bi Ea Mfififiw%W—flbzw l/m%//%" M%WM?W4: a 13 14 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK va? /Z’ZM%W/M// WW m KM fo fyjé/V?‘ f Ts (Fr mae SW = , =- * =-- /é702 py J' mmm" #9 W sme Afr "* e- 25,0 (a; —ff—2«_M— y-= Gee ' forst WWWflfléw—fi’éfl/ 'M¢<¢2WM7Z@W¢ zé WWfi/t THE EARLY STRUGGLE FOR WATER MW (Xx/ahfio-VM ,M 9)po Cozrvera CeveC Of as Fee /%o/ 4 nag??- yW/éerQ/ng/MW Wafi W%/W97WQZMWQM Ce Reiter) To prewar Goce To o. e predofo rh reggeine d fer Clie [/ fPrfer # eC Ue. | soe Pose recess Jy w oee {- Po z Iacimfe - W A Lhe fPevsaecerie 5 % Q RoVxzQ W/é/V47( éZW f Or 210 fere abso absrer BSO Aage or v» fa. 21 2 WJmfiuiLyh¢é Ls... | Ta: cer wr TH. prius Mess P RAIC. paese Forze . 15 16 THE THE FIRST PIPELINE The initial project involved the construction of a diversion dam on Hobart Creek (fig. 1) from which a wooden flume 18 inches deep, 20 inches wide, and 24403 feet (4.62 miles) long, conveyed the water to a tank at the inlet of the pressure pipe (fig. 2). The pressure pipe formed an inverted siphon which was 1114 inches in average inside diameter and 7 miles 140 feet in length. At Lakeview Hill saddle the pipe was 1,997 feet lower than the intake and at the outlet end of the pressure pipe a wooden flume 16 inches by 18 inches in cross section and 21,370 feet (4.04 miles) in length STORY OF THE WATER SUPPLY FOR THE COMSTOCK He vWW/mme/fl conveyed the water to a saddle where a reservoir named Five Mile Reservoir was later built (fig. 3). From the reservoir site a wooden flume followed around the mountainside, a distance of 29,970 feet (5.66 miles), to tanks located above Gold Hill and Virginia City (fig. 4). Good descriptions of the water system have been given by Galloway," DeQuille,*" and Lord." Some dis- crepancies exist, especially as to elevations. In 1964 Walter G. Reid, P.E.,* ran a level profile from Marlette Lake to the Virginia City Tanks for the State of Nevada. The Reid elevations compare closely with the latest topographic maps of the U.S. Geological Survey, and are no doubt correct. His profile indicates that THE FIRST PIPELINE 17 amana. 1.1-Red House and diversion dam about 1928, located below Hobart Creek Reservoir. Courtesy of Harold Berger. 3.-Outlet end of the inverted siphon between Lake- view and Five Mile Reservoir, 1968. Carson City appears in the distance. FreurE 2.-The Tanks, 1969. At this point water entered the inverted siphon. Picture by George Woods. Courtesy of Harold Berger. the pipe at Lakeview Hill saddle is 1,997 feet below the intake and the outlet end of the pressure pipe is 471 feet below the intake. The pressure head at Lake- view saddle (the vertical distance from the pipe to the hydraulic gradient of the pipeline) was 1,887 feet, giv- ing a pressure of 819 pounds per square inch. The important elevations obtained by Mr. Reid are herewith shown. Marlette Lake..__cL___:_:_ 7,838 feet (high-water line). FrGuUrE 4.-The old flume between Five Mile Reservoir and Hobart Reservoir_________ 7,554 feet (high-water line). Virginia City and the pipe replacement. Shown is Hobart Inlet to pressure pipe_____ 7,140 feet (Tankhouse, the Tanks). Leonard, President, Virginia City Water Company. Lakeview Hill saddle______ 5,143 feet (lowest point on pipe- line). Ontieclof ipe..-...}... 6,669 feet. The const‘ructlpn of the flumes p‘re.sented no problem, Five Mile heservoir__.____ 6,645 feet. but the engineering problem pertaining to the inverted Virginia City water tank-_ 6,525 feet. siphon was of great magnitude, as up to that time no 18 THE STORY OF THE WATER pipeline had been constructed subject to a pressure head of 1,887 feet, or 819 pounds per square inch. It is likely that one of the reasons the water company desired Mr. Schussler's services was because of his pre- vious experience in the design and construction of pres- sure pipelines for the Spring Valley Water Works and for the Cherokee Hydraulic Mining Company. For the latter company he designed and supervised the construc- tion of a 30-inch pipeline 12,100 feet long, which crossed a branch of Feather River near Oroville, Calif., and which was subject to a pressure head of 930 feet, or a pressure of about 400 pounds per square inch-about one-half of the pressure of the Virginia City pipeline at Lakeview Hill saddle. The writer was fortunate to find a very illuminating article concerning the Virginia City pipeline in the De- cember 13, 1873, issue of the Mining and Scientific Press in the Mackay School of Mines Library at the Univer- sity of Nevada. According to the author of the article, the information as well as the illustrations were fur- nished by Mr. Schussler shortly after the first pipeline was completed. In describing the specifications of the pipe, reference will be made mainly to this article, al- though the specifications noted by Galloway are similar but not as detailed. The iron used consisted of 10 different numbers of the Birmingham gauge, graduated from No. 16 (0.062 inch) to No. 0 (0.312 inch). The firm of MceCrindle and Company of San Francisco furnished the Scotch iron, which was shipped from Scotland in plates 3 by 10 feet. The George C. Johnson & Company of San Francisco furnished the rivets, which were of American manufacture. The contract for fabricating the pipe was awarded to the Risdon Iron and Locomotive Works, also of San Francisco. This company had made most of the iron pipe in use at that time in the hydraulic mines in California, especially when high heads were needed. The Mining and Scientific Press article stated that ". .. after three months use, the pipe has proved won- derfully successful. It is worthy of remark, as show- ing the kind of pipe turned out by the Risdon Works, that there was absolutely no leakage in the pipe joints, it only occurring at the lead joints where the pipes are joined together." The pipe lengths, having an average inside diameter of 11%, inches, were fabricated at the Risdon Iron and Locomotive Works by cutting the plates and roll- ing them into a cylinder and lapping the edges an amount sufficient to permit two lines of rivets to be driven, thus forming a "double riveted" longi- tudinal joint. The sections thus formed were about 36 inches long and were joined to form individual lengths SUPPLY FOR THE COMSTOCK of pipe 26 feet 2 inches long. The transverse, or cir- cular, seams between the 36-inch sections were over- lapped and single riveted. At one end of each pipe length a nipple 6 inches in width was riveted, with 3 inches projecting beyond the pipe. Joints between sec- tions in the field were made by placing a wrought iron ring, 5 inches wide and of sufficient diameter to leave a space of three-eighths of an inch between the inside of the collar and the outside of the pipe. This space was filled with lead and calked to make a tight joint. A total of 35 tons of lead was required to seal the joints in the field. The total weight of the pipe in place was given as about 700 tons. Figure 6, copied from the Mining and Scientific Press, shows the lead joint in detail. All the iron pipe used was coated, inside and out, with a mixture of asphaltum and coal tar, thoroughly boiled together. Each separate length of pipe was plunged and rolled about in a batch of this mixture for T to 10 minutes before being shipped. The fabrication of the pipe commenced in March 1873, and it was in place and water was flowing 5 months later. The pipe was shipped to Reno on the Central Pacific Railroad and thence to Lakeview by the Virginia & Truckee Railroad, which had only completed the see- tion from Reno to Carson City on August 24, 1872. The first section of pipe was laid June 11, 1873, and the last on the 25th of July of the same year. The lay- ing of 7 miles of 12-inch pipeline over very rough ter- rain in just 6 weeks was obviously a remarkable feat, keeping in mind that the motive power was men and mules. Schussler's original specifications called for a trench 4 feet deep in which to lay the pipe, although DeQuille gave the depth as 214 feet. Probably this varied, depending on the hardness of the material the trench penetrated. No doubt much of the trench was dug prior to the arrival of the pipe. The 14.32 miles of wooden flumes, together with the diversion works on Hobart Creek, were also ready to convey water as soon as the pipe was laid. DeQuille wrote that the course of the pipeline was surveyed in the spring of 1872. The Risdon Iron and Locomotive Works was furnished with a diagram of the elevations and the course on which the pipe was to be laid. Each section of pipe was accordignly made to fit a certain spot. Where the route lay around a point of rocks, the pipe was made to fit the required curve, and other curved sections were required where the line crossed deep and narrow ravines. There was just one place and none other for each section of pipe as re- ceived from the iron works. At each point where there was a depression in the pipeline, a blow-off valve was installed for the removal THE FIRST PIPELINE 19 of any sediment and on the top of each ridge an air valve was placed for blowing off the air when the wa- ter was first let in and at other times when the pipe was filled. The so-called air valves were also designed to admit air, should a break occur in the pipeline below the air valve, and within its district. This device would thus prevent a vacuum and a collapse of the pipe. There were 14 air valves and 15 blow-off valves (fig. 5). Figure 6 shows an example of the elbow designed for the purpose of making short curves in the line of the pipe around rocky bluffs and through sharp canyons. Angle irons were riveted on the pipe on the outside of the curves, which, by means of iron straps, were con- nected with the corresponding angle iron on the next pipe. Figure 5 also shows the manner in which the pipes and elbows were strapped together, wherever the curve was sufficiently short to require this precaution against an outward movement. An iron strap was put on the out- side of the curve to strengthen the pipe. The elbow, as shown in fig. 5, was made in San Francisco, the angle varying according to the degree of curvature. Figure 5 shows the profile of the pressure pipe across Washoe Depression and the location of the air valves and blowoffs. In addition to the special fabrication of the curved portions of the pipe, the foundry also took the pres- sure differences into account in maunfacturing a par- ticular length of pipe for a particular location. At the point of heaviest pressure the iron used was No. 0 gauge (five-sixteenths of an inch). The water pressure de- creased gradually as the ground rose to the east and west from the Lakeview saddle and the iron decreased in thickness from five-sixteenths at the saddle to one- sixteenth of an inch toward both the inlet and the out- let. On its course to the outlet, however, the pipe crossed a great many spurs and sags, and the thickness of the iron was varied to accommodate the changes in pressure. The Mining and Scientific Press stated that although the inlet had a perpendicular elevation above the out- let of 465 feet (Reid's profile indicated a figure of 471 feet) only 300 feet were used, as that head would sup- ply 10 times as much water as Virginia City and Gold Hill had theretofore used. With this head, the pipeline could carry about 2,000,000 gallons per day ; by increas- ing the head to its full capacity, the supply would be increased to 2,350,000 gallons per day. With the water running under a 300-foot head, there was a perpendicu- lar pressure head of 1,720 feet, or about 750 pounds to the square inch at the Lakeview saddle. Perhaps the reader may be confused by the quote that only 300 feet of available head was used. Head, as used here, is the difference in elevation between the intake to the pressure pipe and its outlet. The greater Leap Jon 9 Are Uhave A Orr Uiromua ano Goro FMui Waree Company Proen.« ano Pmrassunme Prima Across Wasros Derma ssi.ont 1873 Amid fun Bestices Treat. simpy iy A S Dow's - Cad | - Ali Cariemay 1939 Cinl Engines 5.-Profile of siphon and location of air and blow-off valves. Courtesy of Nevada Historical Society. 20 the head, the more water the pipe will carry. As con- structed, this difference was 465 feet, but as the water company didn't need the full capacity at first, the inlet at the tank was lowered a vertical distance of 165 feet. With this lowered head, the pipe carried 2 million gal- lons per day. The need for water increased rapidly, and no doubt within a short time the pipeline was used to its full capacity. 2 The Risdon Works tested the pipe at the foundry to a maximum pressure of 1,400 pounds to the square inch. After installation, the pipe was tested in place using the full head. Immediately after the pipe was put in use, some of the leaded joints developed leaks, primarily as a result of the longitudinal movement of the pipe due to ex- pansion and contraction. Captain John B. Overton, who was Superintendent of the Virginia and Gold Hill Water Company, realizing that this trouble would con- tinue, took emergency measures to correct this condi- tion. A clamp was developed that fitted over the 5-inch collar, and when tightened, forced the lead back in place. Then permanent brackets were fitted over the col- lar. Figure 6 shows the clamp as it was used to force the lead back. A sample of the permanent bracket is shown resting on the pipe. The brackets were 514 inches long and 3 inches wide, with a 1-inch lip at each end. It took 13 of these brackets for each leaded joint (fig. 7). According to Davis, Captain Overton hired all the blacksmiths he could find to make the wrought iron clamps." No figure has been found as to the number of brackets which were made, but it well could have been in the thousands. The newspapers of the period in question often are the best source of information concerning early western history, and in many cases they are the only source. In describing the arrival of Sierra mountain water in Vir- ginia City, the Virginia Evening Chronicle carried the following articles: July 31, 1873-The Sierra Nevada water was turned on again last evening and reached and ran into the flume for some time, when two leaks were discovered by Engineer Schussler and deeming it unsafe to continue the pressure again caused the water to be shut off for repairs to the pipe. It was his intention to turn the water on again at 2 o'clock this afternoon, and he estimates it will take the pumped fluid six hours to reach Bullion Ravine after it passes into the flume, as the latter is dried up. The water will probably reach the Divide be- fore morning. August 1, 1873-Water Works are like brewers yeast hereabouts at this season of the year, when the mercury is up 6,000 feet above the level of the THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK FIGURE. 6.-A section of the first pipe that was laid in 1873. The clamp used to force the lead back into the sleeve is shown at the bottom of the photograph. The permanent clamps are shown on the top of the pipe. FIGURE. 7.-A section of the first pipeline laid in 1873, still in place between Lakeview Hill and Five Mile Reservoir. sea. Yesterday the Sierra Nevada water came through the pipe and ran "up the flume" to a point near the Ophir Grade toll house. Then a "sleeve" THE FIRST PIPELINE (the bell portion of the overlapping pipe) gave way and the water was shut off for repairs to the pipe. The water may reach Bullion Ravine late this afternoon and it may not be for several days. August 2, 1873-The pouring into this city and Gold Hill of a large stream of water from the East- ern Summit of the Sierra Nevada Mountains at 6:45 last evening, marked an epoch in the history of the Comstock, and was the signal for a general jollification and rejoicing of twelve or thirteen thousand people. Bonfires and rockets girdled old Mt. Davidson for hours and cannons continued to roar until a late hour in the night. A stream of 153 inches of water (about 1717 gallons per min- ute) poured through the flume into Bullion Ravine, between this city and Gold Hill. The water was turned into the pipe on the Sierra at noon yesterday and reached here in six hours and forty- five minutes. It had been estimated that it would take the stream eight hours to reach here, a distance of twenty miles, 134 feet. The author lives near the foot of Lakeview Hill in Washoe Valley. It is easy to look across the valley, trace the course of the pipeline towards Virginia City, and visualize the scene that took place as the first water entered the pipeline. As described by DeQuille: As the water came surging down through the great inverted siphon from the elevated mountain spur and began to fill . . . one after another of the blow-off cocks on the crests of the ridges crossed, opened, and allowed the escape of com- pressed air. Compared with what was heard when these cocks blew off, the blowing of a whale was a mere whisper . . . As the pipe filled, the progress of the water in it could be traced by the blowing off of the air on top of the ridges through the valley, and at last, to the great joy of the engineer and all con- cerned in the success of the enterprise, the signal fire at the outlet, on the summit of Virginia range, was for the first time lighted, showing that the water was flowing through the whole length of the pipe." About 4 months after the completion of the first pipe- line, the Mining and Scientific Press observed that "It was an engineering feat of no small magnitude to carry this enterprise to a successful completion ; and in view of the difficulties to be overcome, it will attract the at- tention of engineers all over the world." The same arti- cle noted that the Virginia City pipeline was the great- est in the world, and withstood almost double the pres- sure of the next highest pressure line. The reader will no doubt be interested in learning more about Hermann Schussler. According to the {in- ing and Scientific Press of December 13, 1873, Mr. Schussler was a graduate of the Prussian Military Academy of Oldenburg, of which he was a student from 1859 to 1862, and was promoted 428-017 O - T1 - 5 21 to lieutenant on January 1, 1862. In the fall of that year he took leave of absence for 2 years, and dur- ing that time attended the civil engineering schools of Zurich and Carlsruhe, for the purpose of per- fecting himself in his intended profession of civil engineering. In the fall of 1864 he had his leave of absence changed into a definite leave, and then came to San Francisco where he entered into the service of the Spring Valley Water Works, first as an Assistant Engineer and then Chief Engineer. From that time his career in other large works on the Pacific Coast commenced. He was connected, as consulting engineer, with the Oakland water works, San Jose water works, Vallejo and Stock- ton water works. He was Chief Engineer of the Marin County water works and then that of Vir- ginia City and Gold Hill. During 1873 he was Chief Engineer of the Sutro Tunnel Company (fig. 8). 8.-Hermann Schussler, the consulting engineer who designed the 1873 pipeline system. Courtesy of Hobart Leonard. 22 THE STORY OF THE WATER In addition to the above duties, he was employed partly as consulting engineer and partly as projector in various hydraulic enterprises in California. Mention was made in the article that he projected the Pioche water works in Nevada, where he made a 5-inch pipe of No. 16 iron, 6 miles in length, sustain a vertical pressure of 600 feet. The article mentioned other proj- ects he worked on, and concluded by stating . . "other undertakings could be mentioned if space permitted, but enough has been given to give our readers an idea of his ability in hydraulic engineering." In researching the installation of the Tuscarora (Elko County) pipe line, it was noted that Mr. Schus- sler was employed as a consultant for the Tuscarora Water Company in 1888. Also, as previously noted, Mr. Schussler surveyed the alignment of the Sutro Tunnel in 1869. Figure 9 shows the essential features of the first pipe- line, as well as the two later pipelines and other facil- ities. This map was prepared by E. D. Boyle, Mining Engineer, in 1913. Mr. Boyle served as State Engineer in 1910 and served as Governor of Nevada from 1915 to 1922. It is to be noted that the 1873 pipeline has the most bends, while the 1887 pipeline is the straightest. THE SECOND PIPELINE Commenting on the water supply of Virginia City, the Territorial Enterprise of June 17, 1875, had this to say : One of the boasts of Virginia City, Gold Hill and Silver City is, that in this land of barrenness-of shifting sands and burning alkali, they have the purest and best mountain water and plenty of it. Nor is the boast lightly made. There is no place in the world where so many natural difficulties have been overcome and so many triumphs achieved as in bringing the pure, fresh and soft water of the Sierras across Washoe Valley and into the places above mentioned . . . but already is the necessity arising for an increased supply. Mills are daily re- quiring more and more; the mines an increased supply for steam and other purposes; people are flocking in by the thousands, and manufactures are increasing in proportion. . The Gold Hill Doily News of July 1, 1875, also de- scribed the need for an increased supply : The supply of water for milling and mining pur- poses has been gradually lessening for the past two weeks and if the utmost economy is not exercised in its use by our people, may continue to do so until even some of our mills may have to suspend operation. During the past week the Virginia Con- solidated Mill has lost four hours per day, for the want of a sufficient supply. The Water Company SUPPLY FOR THE COMSTOCK wisely looking forward to such a necessity, has already got the placing of another line across Washoe Valley well under way. The need for a larger water supply for fire protection was made evident on October 26, 1875, when the major portion of Virginia City and the headworks of the prin- cipal mines were burned in a fire that lasted through- out the day. Long before this, and in fact as early as 1873, preliminary plans for another pipeline across Washoe Valley were developed. It was estimated that during the spring months the flow of Hobart Creek could furnish more than 25 mil- lion gallons daily ; however, it was not possible to store the excess water, and during the summer months the flow diminished until it dropped to about 700,000 gal- lons per day. An added supply of water was needed, and could only be obtained from the western side of the Car- son Range of the Sierra Nevada above and east of Lake Tahoe. The Territorial Enterprise of August 17, 1875, stated that some idea of the increase in the consumption of water in Virginia, Gold Hill, and Silver City during the preceding few years could be formed from the fact that the amount used in 1875 was 100 times greater than that used in August of 1873. The article also in- dicated that when the Consolidated Mill started operat- ing that spring, the full capacity of the water company's supply pipe was reached. The article described the new water supply as follows: The Company being determined to keep pace with the wants of the community . . . at once set about taking the necessary steps toward laying a new pipe and largely increasing their source of supply. The outlay involved in the improvements will be somewhere in the neighborhood of $600,000. The cost of their present works was $750,000. Ground for the bed for the new pipe was broken on the 1st of May last. The new pipe, which was manufac- tured by the National Tubing Company of Mc- Keesport, Pennsylvania, is ten inches in diameter and five-sixteenths of an inch in thickness, and welded instead of being riveted together. The joints are constructed so as to be serewed together like gas-pipe, no riveting being required. Messrs. Breed & Crosby, of this city, upon whom developed the business of hauling the pipe from the railroad up the steep mountain sides, have executed their task with commendable dispatch. Nearly all the pipe is on the ground and ready to be placed in position. No haste, however, will be used in laying the same, as the old pipe carries all the water which the Com- pany can at present control. As described by Galloway, the work was started on the trench May 1, 1875, and the pipeline completed that year."" The pipe sections were of wrought iron, 16 THE SECOND PIPELINE 23 feet in length and one-fourth of an inch in thickness; the seams were lap welded and the joints screwed to- gether. The cast-iron sleeves and lead packing used on the first pipeline were being discarded. The pipe was 10 inches internal diameter, and was designed to deliver about 2 million gallons per day, the same capacity of the first pipeline (Fig. 10). The pipeline closely fol- lowed the route of the first pipeline but was 1,900 feet longer, according to Galloway. A second flume from Ho- bart Creek to the inlet tank (The Tanks), 25,005 feet (4.72 miles) long was built parallel to the first flume, and a second tank constructed at the inlet for the pres- sure pipe. From the outlet end of the two pipelines a second flume, 21,050 feet (3.98 miles) long, was built to Five Mile Reservoir, located about 5 miles from Vir- ginia City. The reservoir had a capacity of approxi- mately 5 million gallons of water (fig. 11). A second flume, 38,670 feet (7.31 miles) long, led from Five Mile Reservoir to Gold Hill and Virginia City. The flume was located above the first flume, high above the city, and extended to Cedar Hill at the north end of the city. Another reservoir, constructed to hold 2,500,000 gal- lons, was placed on the dividing ridge between Virginia City and Gold Hill. During the events leading up to the design, construc- tion, and installation of the first pipeline in 1872 and 1873, Herman Schussler was the "man of the hour." He designed the pipeline and supervised its installation. The writer, in carrying on research relative to the second and third pipelines, did not find any further reference to Mr. Schussler in connection with the Virginia and Gold Hill Water Company. The second pipeline, in- stalled in 1875 under the direction of Captain Overton, had an altogether different design from the first line, as noted in the descriptions heretofore given. It should also be noted as a matter of interest that it is this see- ond pipeline which is still in use across Washoe Valley and Lakeview saddle. Apparently Captain J. B. Overton was not only the superintendent of the water company but also carried the main responsibilities in the development of addi- tional water supplies. The Territorial Enterprise of August 17, 1875, made the following comments regard- ing Captain Overton : The controlling spirit in the planning and execu- tion of the present work is Superintendent Overton, a man of tireless energy and limitless re- sources, who devotes himself with a remarkable self-sacrificing spirit and zeal to the interests of the Company: He superintends, personally, the minutest details of the great enterprise; is appar- ently everywhere at all times, infusing his own indomitable energy into the men employed on the work, and is the especial terror of shirkers. He does not believe that anything is impossible in combat- ing with the forces of Nature. A modest and un- assuming gentleman, he enjoys in a high degree the confidence of the Water Company, and had carte blanche to carry out his plans as seem to him most feasible and best. If the San Francisco Water Company people had half of Superintendent Overton's energy they would, long ere this, have had the water of Lake Bigler (Lake Tahoe) run- ning into their city. Even now, we doubt not, Over- ton is meditating some plan to steal the waters of the beautiful lake and abduct them to this city. The work of bringing water that normally drained into Lake Tahoe from the western slope of the Carson Range of the Sierra Nevada to augment the water sup- ply of Virginia City involved increasing the storage capacity of Marlette Lake. From the lake the water was conveyd by flume northward to a tunnel, and from there conveyed to Hobart Creek (fig. 12). Galloway described Marlette dam in this fashion : On the western side of the mountains a small lake, named after Marlette, the Surveyor General of Nevada, had previously been made into a reservoir by the Carson and Tahoe Lumber and Fluming Company. That company had built from the lake or reservoir a "V" flume leading southward to Spooner Summit at the head of the main flume down Clear Creek, the water being used for flum- ing purposes. Arrangements were made by which the Marlette Dam was raised. As completed, the dam was about 213 feet long, 37 feet high, and 16 feet wide on the crest, with battered sides. The exterior walls were of dry rubble masonry with rough coarse laid stones. There is an interior core of earth to provide the necessary impervious ele- ment. There are 3,825 cubic yards of masonry and 1,365 cubic yards of earth in the dam. The lake formed is about 1% miles long by % mile wide, and is said to contain 2,000 million gallons of water. It lies at an elevation of 8,000 feet above sea level. ** (See fig. 13.) From Marlette Lake a flume 14 inches by 30 inches in section and 23,175 feet (4.38 miles) in length leads to the west portal of the water company's tunnel through the ridge which divides the Lake Tahoe drainage from that of Hobart Creek on the eastern slope. The tunnel, excavated in granite, was 3,994 feet long, according to Galloway. Both DeQuille *" and Thompson and West ** erroneously give the tunnel length at 3,000 feet. Over one-half of the tunnel was timbered, its size being 7 feet high, 414 feet wide at the top and 6% feet wide at the floor. Eliot Lord states that the connection between the two headings was made on May 13, 1877." 24 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK ,"’ "‘7’,;Ev£'"'—’ nl trate i m 74 | As | i [32 ‘i ' a ‘ 249 19 £0 2/ it, 23 | 1 | tk I / | y __fi____‘h, 15 | // 1 "I, | f 55 | ‘ 27 26 25 Jo £9 28 Z6 I , 4 ils _( 187 w/ (T 24 3s (> * 36 3, 3/51/11” V 34 , £ as ‘J -| \—Q/ { | 3 f \ rory es 1T. 16 M s; 3 | 2 / 6 a 4 3 £ a « tes | t ; | 3 i \\l/( / | \ . 10 v2 f 7 ”v/a a 10 / /< 7 z2N £1 czas h 4 3 2 1 \ \ \ R 2 o // NJ £35; r T/ ”é ”if a k $* h /6 15 14 # A Freur® 9. -General map of the water works system THE SECOND PIPELINE p p £. Ld + 24 19 Zo 2/ #2 23 24 J 2o Im o Vize! £ A7 <6 #4 - air 21 arco Diride Ra iro Hinz 34 35 36 a/ T ir n. J 17 3 2. 3 F 4 / "l% 5 jae Mile Reserves £ ez uf - { & & & 10 v/ & y ! Hert 39g A's £ % l & IIL § To" & § & 45 /4 43 18 17 ; § | so" Syphon. Pipe Outlet & 7 a eres bj Z2 25 12 Zo \ \\ \ #7 z6 25 ) Jo J I4 35 36 / #2 T 16 /% 7 0 ». 3 Z / /\x\ his: J.) M P or Tne a W 10 / z «e ieane. Mon 1" MAILER m; SHSTEM vimema & cad Hit Co. 79 accommany ine * REPORT OF £0. BOLE, ME. compuco rmom mens STATE - a us mifs, & S L rax 16 45 14 49 apmMiTE Sumrers tx ws 1 0 1 MILE C ___ nc L Lcc of the Virginia and Gold Hill Water Co., 1918. 25 26 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK FrGuRrE 10.-The screw-joint pipe used in the second pipeline, 1875. The August 17, 1875, issue of the Territorial Enter- prise described the location of the tunnel and the meth- od of construction in the following manner : The Company has entered upon the herculean un- dertaking of getting control of Lake Marlette by running a tunnel through the Sierra Nevada Mountains. The point where the distance through the mountain chain is shortest, and the tunnel could be run most economically, is a high bluff nearly directly west of this city. The tunnel, which will be forty-two hundred feet in length (actuall 3,994 feet), pierces this mountain chain at a dept}: of five hundred feet and is five miles north of Lake Marlette. The reason for the long detour is made from the lake to the tunnel is that a wooden flume can be built at much less expense than tun- neling through a mountain. The tunnel, if run di- rectly east from Lake Marlette, would have been four miles in length. . . . The work of surveying the route for the flume and tunnel was performed chiefly by Mr. Alfred Cravens, a young gentleman of acknowledged ability, who has executed his task entirely to the satisfaction of the Superintendent of the Company. The article went on to say : The work of running the tunnel has already been commenced, and is being pushed ahead energeti- cally, all the modern appliances for assaulting mother earth being called into requisition. Tun- neling is carried on from both ends under the di- rection of John Simpson and Thomas Brown, both of whom rank among the best miners on the coast. Power drills of the Rand pattern are used for FrGuRE 11.-Five Mile Reservoir and the old caretaker's house, 1968. FicurE 12.-The west portal of the tunnel through the Carson Range of the Sierra Nevada as it appeared in 1968. tunneling purposes. They are driven by com- pressed air, one engine doing the work for both ends, besides furnishing air for ventilation pur- poses. In order to carry the compressed air to the west end of the tunnel, the engine being stationed at the east end . . . a string of iron pipe had to be THE SECOND 27 PIPELINE | | FiGUurE 13.-Marlette Lake, 1920. Courtesy of Harold Berger. laid over the mountain a distance of over a mile. Through this pipe the air is forced into a receiver stationed at the west end of the tunnel, from which it is drawn at will. About one hundred and fifty feet of tunneling has been completed at each end, and it is thought that the entire work will be fin- ished by next May (1876). . . . As heretofore mentioned, Lord noted that the con- nection was actually made May 13, 1877. The T'erri- torial Enterprise of July 4, 1877 stated : "Last Satur- day the Water Company completed their connection with Marlette Lake and let the water go through for a test." So, even though the second pipeline was laid across Washoe Valley in 1875, no water from Marlette Lake reached Virginia City until about July 1, 1877, almost 2 years later. It would seem likely, however, that the second pipeline carried Hobart Creek water prior to that time. From the eastern portal of the tunnel a flume 14,610 feet (2.77 miles) long conveyed the water to a small diversion pond on Hobart Creek. In traveling along the pipeline from Lakeview saddle towards the outlet, the writer noted that at a distance of about 1 mile a block of concrete had been poured over the three pipes. This was on a rather barren southern slope, and apparently it was found necessary to anchor the pipe at that point. From looking at the structure, it appears likely that after the installation of the see- ond pipe a concrete block was used to hold the 1873 and 1875 lines. After the installation of the third pipe in 1887 another block of concrete was added (fig. 14). FIGURE 14.-Concrete block used to anchor the pipeline between Lakeview saddle and the siphon outlet. In the foreground is shown the 1875 pipe; on the far side is the 1887 pipe; and at right lower edge of the photograph the 1873 pipe can be seen. Picture by Allan Shamberger, 1968. 28 THE STORY OF THE WATER SUPPLY FOR THE THIRD PIPELINE The production of silver and gold ore dropped off sharply following 1878 and reached a low in 1881, when only a little more than $1 million worth of ore was mined. This low period of production held somewhat steady until 1887, when production sharply increased. That year it reached a high for the period following 1878, when the value of ore produced amounted to more than $7.5 million. Virginia City, as well as Gold Hill and Silver City, continued to build new mills, business establishments, and homes, during this 1878-87 period. The Septem- ber 28, 1878, issue of the Mining and Scientific Press in commenting on Virginia City had this to say : Population about 25,000 . . . and as written by a prominent journalist of Gold Hill, "it contains more millionaires than absolute beggars." It has all the features of a great metropolis, hotels, stores, places of amusement, churches, clubs, banks, four or five daily journals, foundaries and machine shops, a railroad with 32 arrivals and de- partures daily, water works superior to that of any other city in the world furnishing an abundant supply of pure, soft water direct from the springs and snow-fed streams of the Sierras. The increased activity on the Comstock and the de- mands for additional water caused the water company to construct a third pipeline across Washoe Valley, and also to develop new sources of water. The Territorial Enterprise of July 27, 1887, stated that Captain J. B. Overton, Superintendent of the Virginia and Gold Hill Water Company, had designed and supervised the lay- ing of [ miles of new iron pipe across Washoe Valley. This new pipeline was substantially in the same loca- tion as the first two pipelines. As described by Galloway, it was made of lap-welded pipe similar to the second pipeline, except that the joints were of the converse lock- jointed type." The pipe walls were three-sixteenths, one-quarter, and three-eighths inch thick ; the inside di- ameter was 1114 inches and the length 37,685 feet (7.15 miles). On one end of each of the 21-foot sections were two knobs, the other end being fitted with a lock-joint sleeve with a layer of lead already in place. On assem- bling, the end with the two knobs was pushed into the lock joint and turned to secure "a lock." Lead was then poured in to make this a seal. This lock-joint sleeve was patented in 1882 (fig. 15). In addition to its discussion of the new pipeline, the July 27, 1887, issue of the Territorial Enterprise de- scribed other work done during the spring of 1887 under the supervision of Captain Overton. A new flume was constructed from the inlet of the three pipelines to Ho- THE COMSTOCK FicuRE 15.-The pipe at the bottom of the photograph is the type used in the third pipeline, 1887. Next up from the bottom is the type used in the 1873 pipeline. The top section shows the method used in repairing a broken pipe. bart Creek, and the original flume from the east portal of the tunnel to Hobart Creek was replaced by a much larger flume. Also, from the west portal of the tunnel, a new flume would be put in to Marlette Lake. In order, however, to increase the water supply sub- stantially, it was determined that a new flume running northward from the west portal of the tunnel along the mountains rimming the east shore of Lake Tahoe was needed. The same issue of the Enterprise stated that Captain Overton was then employed in the construction of a new flume, running northwesterly from the west portal of the tunnel a distance of 9 miles to North (Third) Creek, which would tap several streams tribu- tary to Lake Tahoe. Galloway stated that this flume was 43,523 feet (8.25 miles) long, extending to Third Creek, which was some- times referred to as North Creek." The airline distance from the tunnel to the start of the flume at Third Creek was about 414 miles. In addition to the water of Third Creek, the flume picked up water from First and Sec- ond Creeks, Mill Creek, Tunnel Creek, Incline Creek, and other small streams along the way. This flume emptied into the Marlette Lake flume at the tunnel's west portal. The aforementioned issue of the Territorial Enter- prise of July 27, 1887, stated that to conserve the water THE THIRD PIPELINE 20 FicurE 16.-Hobart Creek Reservoir about 1928. The tree stump was and still is the measuring gage. The dam is shown in the upper right. Courtesty of Harold Berger. supply and to have a reserve to draw upon, a small stor- age reservoir was being constructed on Hobart Creek about half a mile above where the flume from the tunnel emptied into it. The dam was about 350 feet in length and 20 feet high, and the reservoir so formed held about 35 million gallons, or about 100 acre-feet. This storage represented about a week's water supply for the Com- stock (fig. 16). Also, during that same period a new flume was built from the outlet of the pipes to Five Mile Reservoir. Captain J. B. Overton was in charge of the construc- tion of all the works described herein, and in addition he designed the second and third pipelines after Mr. Hermann Schussler had designed the first pipeline built. Captain Overton, in addition to his responsibil- ities as Superintendent of the Sierra Nevada Wood and Lumber Company, was responsible for the development of the water supplies as well as being Superintendent of the Virginia and Gold Hill Water Company from 1873 to 1906, at which time Mr. James M. Leonard became superintendent (fig. 17). The white house at Lakeview Saddle was built about 1873, and Captain Overton, although never living at the house, maintained quarters there until he retired in 1906. The structure is presently occupied by Harry E. "Red" McGovern, who has been in charge of the water system from Marlette Lake to Five Mile Reservoir for many years (fig. 18). Prior to Red's residence at the Lakeview house, it was occupied by Mr. Tom Higgins from 1899 to 1906 and by Mr. Joe Berger from 1906 to 1985 when he retired. The reader will learn a little more about these two men later in this story. Lord states that to protect the city in case of fire, pipe- lines aggregating 4 miles in length were laid in Virginia City, Silver City and Gold Hill." These were 2%4 miles of 10-inch and 114 miles of 8-inch pipe. This pipe belonged to Virginia City, as well as 2% miles of smaller supply lines. The length of the pipelines belong- ing to the water company which ran through the streets FicurE 17.-Captain John Bear Overton, Superintendent of the Virginia and Gold Hill Water Company from 1873 to 1906. Courtesy of Hobart Leonard. 18.-The white house at Lakeview, built about 1873. The Sierra Nevada looms in the background. 30 THE of Virginia City, Gold Hill and Silver City was 14 miles, and through this system of pipes and flumes 4,200,000 gallons of water was distributed daily through the towns on the lode, the mine works consum- ing two-thirds of the supply. Galloway mentions that three large wooden tanks, each holding 30,000 gallons, were built on the line of the flume above the cities, and in addition, there were large storage tanks at the numer- ous mines. Also on the high ground of the "Divide" between Gold Hill and Virginia City, a distribution reservoir was built with a capacity of 2,500,000 gallons. The water rates in 1880 were 20 cents per 1,000 gallons to the mining companies and $4 per month to families of six or eight persons. Eliot Lord, quoting from a statement by J. B. Overton, gave the total cost of the water company's plant, including flumes, dams, reservoirs, pipes, water rights, litigation, etc., as $2.2 million. RECAPITULATION OF WATER WORKS, 1873-1887 The extent of the water-supply system is shown in the following recapitulation. The writer can only echo the statement made by Galloway that "as built, the water supply was a notable addition to the art of water supply engineering." Flumes to Pressure pipe - Flume from Flume from Supply line _ inlet of pres- inside diameter outlet of pi Five Mile Divide sure Pl and length to Five Mile Reservoir to tunnel and year (mi esge (inches and Reservoir Virginia City (feet) miles) (miles) (miles) First, 1873...... 4.62 1114, 7.0 4.04 5.00 ..../..:« 12.77 Second, 1875.... 2 3 g 10, 7.32 3. 98 7.31 3, 994 3 4, Third, 1887..... 48.25 112§, TMB reer re le Like cee ee seee aer an Total.... 24. 74 21. 47 8. 02 12.97 _ 3,994 1 Flume from east portal of tunnel to Hobart Creek. 2 Flume from Hobart Creek to inlet pipe. 3 Flume (14"X30'') from Marlette Lake to west portal of tunnel. + North flume, starting at Third Creek north of Incline, to west portal of tunnel. Potal length of pipelines;. ...... ss.. 2200. 0.0000 00.000 eres 21.47 miles. 'Potal length iof Atuneg .s 22002 02.0 Le.. -- 45.73 miles. DUNNE Z2: . 27.11. cour? 2000000000000 ee 20s ee eved - 8,994 feet. Marlette Lake capacity... as Hobart Creek RESeTVOI. ..... 00. Five Mile RESETVOIT. .::. ..... 0.000. ood eee decease cie a's 6,154 acre-feet. 100 acre-feet. 15 acre-feet. WATER-RELATED EVENTS, 1861-1894 While this is intended to be a factual history of the development of the water supply from the Sierra for the Virginia City area, there were other events taking place in which these waters were utilized. These events were of importance to the early development of the Comstock and are worthy of being briefly related here : 1. The use of the water from the north flume to float lumber via a V flume from the incline STORY OF THE WATER SUPPLY FOR THE COMSTOCK tramway on Mill Creek through the tunnel to Lakeview. 2. The Sutro Tunnel. 3. The use of water from the Virginia and Gold Hill Water Company's system for the develop- ment of power at the C & C shaft and the Chollar shaft at Virginia City by means of Pelton Wheels. 4. Development of electricity for town use by the Virginia City Electric Light Company. 5. Pumping water from the deep mine shafts on the Comstock. The Sierra Nevada Wood and Lumber Company The history of this company has been rather well documented by E. B. Scott in his The Saga of Lake Tahoe, 1957 ; in David F. Myrick's Railroads of Nevada and Eastern California, 1962; and in John D. Gallo- way's Harly Enginering Works Contributory to the Comstock, 1947. The author will borrow heavily from these three authorities in recounting briefly the details pertaining to this lumber company. The Sierra Nevada Wood and Lumber Company was organized by W. S. Hobart and Seneca H. Marlette in 1878. Captain John Bear Overton, the Superintendent of the Virginia and Gold Hill Water Company, was appointed General Manager, and until the cessation of the lumber company's operations at Lake Tahoe in 1896, he served in this dual capacity. This company was one of the three major lumber companies supplying the Comstock during the period of greatest demand for cordwood and lumber. By 1880 a steam-powered sawmill was completed about half a mile from the shore of Lake Tahoe, on Mill Creek, and about 1 mile easterly of what is now known as Incline. Galloway states that the tunnel and water flumes of the Virginia and Gold Hill Water Company furnished the basis for the plant of the Sierra Nevada Wood and Lumber Company." At a point on the north flume about 1% miles from the western portal of the tunnel the mountainside is very steep. It was here that the com- pany built a double-track tramway from near the mill, up the mountainside to the vicinity of the water flume. Scott terms it the Great Incline of the Sierra Nevada. He describes this structure as follows: A double track narrow gauge-tramline, 18 feet in over-all width, was engineered by Captain Over- ton to run straight up the side of the mountain east of the mill. Cross ties spiked to a solid log bed carried the rails on which the lumber and cord- wood cars were to operate, with the cars canted at at angle so that a near level inclination could be WATER-RELATED EVENTS, 1861-1894 31 maintained on the steep grade. From the staging yard adjoining the mill, a spur track feeder line ran southeast one-eighth of a mile to join the tram- line near its base. Here the carriers were loaded for the trip up the 4,000 foot-long, 1,400-foot vertical lift to the V-flume running below the granite out- cropping that anchored the top of the structure. Three-quarters of the way up the mountain, an eight-foot rise in every twelve was encountered, giving a 67 percent track gradient. The machinery and equipment consisted of more than 8,000 feet of 114-inch endless wire cable fed around two massive 12-foot diameter, eight-spoked bull wheels. The wheel at the summit was driven by a gigantic sprocket and gear turned with a 40-horsepower steam engine embedded into a granite-walled powerhouse. Ten- by twenty-inch timbers were bolted to solid rock and se- cured with iron rods and ring bolts to support the weight of the terminal wheels, with the cable ambigu- ously described as "running near the tops of the cars and hitched on top of the hind ends." The V lumber flume paralleled the water company's flume and the latter furnished water for the transporta- tion of the lumber and cordwood. The V flume extended through the 3,994-foot water company tunnel and thence descended about 2,500 feet to a lumberyard at Lake- view. In passing through the tunnel the lumber flume was located directly above the water-supply box flume to Hobart Creek. Red McGovern told this writer that, according to reports he had heard, when the V lumber flume was in operation, the water from the north flume (Third Creek) was used during the day to transport lumber, and during the night the water was commingled with Marlette Lake water and went to Hobart Creek and thence to the Virginia City area. The lumberyard at Lakeview was located just south of the Lakeview house. The Virginia & Truckee Rail- road main line passed a few feet west and south of the house, and spurs were built to the lumberyard. About the only evidence left of the Sierra Nevada Wood and Lumber Company's operations at Lake Tahoe is the path of the Incline Great Tramway, and at the top there still remains one of the massive bull wheels which carried the endless cable. Myrick states that initial timber cutting by the Sierra Nevada Wood and Lumber Company was made about a mile north of Crystal Bay. To service the area, a 1%,4- mile narrow-gauge railroad was constructed in the spring of 1881. Later the rails were extended several miles both northerly and southerly, the southerly ter- minus being at Sand Harbor. Logs were assembled in V-booms at Hobart, at the south end of Lake Tahoe, and rafted nearly 20 miles to Sand Harbor, where they were loaded on the narrow-gauge cars and conveyed to the sawmill." The V lumber flume was continuous from its start at the top of the Incline Tramway through the tunnel and thence to Lakeview, a distance of about 10 miles. According to McGovern, and apparently for inspec- tion purposes, a special type of float was constructed to convey a person or persons in the V flume through the tunnel and thence down to Lakeview. The speed of the float would depend on the amount of water used in the flume. This, no doubt, was a thrilling adventure for those who dared brave such a ride-especially if a full charge of water was used. Myrick wrote that the last major season of the lum- ber company's operations at Lake Tahoe appears to have ended in the fall of 1894 and that the railroad was abandoned shortly thereafter. However, Scott indicates that 1896 was the last year of Sierra Nevada Wood and Lumber Company activity there."" The Territorial Enterprise of December 2, 1887, quot- ing Captain Overton, stated that during the 8-month period from April to November 1887, the mill produced 12 million feet of lumber, all of which was flumed to Lakeview. E. B. Scott gives a total production figure for the Sierra Nevada Wood and Lumber Company's Tahoe operation, starting with 1879, as approximately 200 million feet of lumber and more than a million cords of wood. Most of this went underground to shore up the galleries of the Comstock Lode, or vanished into the fire boxes of the hoisting works at the mines, and the Cornish steam pumps that cleared the mine sumps of water at Virginia City. Thousands of cords of wood also disappeared through the balloon and dia- mond stacks of the Central Pacific and Virginia & Truckee Railroads' locomotives. The V flume of the Sierra Nevada Wood and Lum- ber Company is mentioned here because of its relation to the Virginia and Gold Hill Water Company's facili- ties. However, the reader should remember that there were at least 10 V lumber flumes in operation on the eastern slopes of the Sierra Nevada. Galloway, quoting from an early Surveyor General's report, stated that in 1869-70 there were 25 miles of flume in Ormsby County. During the period 1879-80, there were 10 flumes in Douglas, Ormsby, and Washoe Counties, totaling more than 80 miles in length, which annually transported 171,000 cords of wood and 33 million board feet of lumber. The Sutro Tunnel In discussing the Sutro Tunnel it is not intended to record the full history of this undertaking as it has been well documented in many publications." The au- 32 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK thor will only outline enough of the facts pertaining to this great undertaking to enable the reader to under- stand the tunnel's primary function-namely, the drain- age of water from the deep shafts on the Comstock Lode, and their better ventilation. The tunnel was also utilized as a means of getting rid of the water pumped from below the tunnel level, thus eliminating the extra pumping distance from the tunnel level to the surface, a distance of about 1,600 feet. Up until 1861 little difficulty was experienced with water in the sinking of shafts on the Comstock; how- ever, with the increased depths, water became a great problem. Not only did the water problem increase with depth, but adequate ventilation of the mines was the most difficult of all problems from the very beginning. It was not until the Root blowers were introduced in 1865 that there was some relief from the air problem. Both the air and water increased in heat and foulness with depth, and in this early period more men died from extreme heat and foul air than from any other cause."" In order to drain the shafts, several tunnels were con- structed prior to the Sutro Tunnel. In 1861 the Latrobe Tunnel and Mining Company constructed a tunnel un- der contract with the mining companies whose ground it would penetrate. These companies agreed to segre- gate a portion of their claims adjacent to it in compen- sation for drainage and prospecting. The tunnel started at a point a little more than half a mile east of Virginia City, and it was estimated that it would strike the Com- stock at a horizontal distance of somewhere near 3,000 feet and at a depth of about 600 feet below the outcrop- ping."" In 1864 this tunnel, 2,800 feet in length, tapped the Sides and the White & Murphy (which later be- came the Consolidated Virginia Company) lode on its dip at 700 feet. A drift was run to drain the nearby Cen- tral and Ophir mines." In 1862 the Cedar Hill Tunnel and Mining Company undertook a similar work, but after tunneling about 2,000 feet, the project was given up. However a more important enterprise was inaugurated by the Gold Hill and Virginia Tunnel and Mining Company in 1863. The plan was to begin at a point in Gold Canyon near Silver City and run a tunnel the entire length of the lode to the Ophir mine, which it would intercept at a depth of about 1,000 feet, and a horizontal distance of 15,000 feet. Work on this tunnel had been in progress nearly a year when the exhaustion of all the upper ore bodies on the lode and the failure to discover any new ones rendered the outlook for the mining industry so dis- heartening that capitalists refused to put more money into the scheme. Accordingly, the work was suspended, and was never resumed.** The October 25, 1925, issue of the Carson Daily Ap- peal contains a letter addressed to the editor from Alfred Chartz, in which some of the early Comstock water tunnels were discussed. Mr. Chartz stated that the first tunnel excavated was the Mint Tunnel, which tapped springs at a depth of 500 feet below the collar of the Hale & Noreross mine, and which was run about 1863. Then he mentioned a tunnel that was excavated in the early days, located at the mouth of Daney Can- yon, which was driven a length of about 1,100 feet. This may be the same tunnel mentioned previously which was started by the Gold Hill and Virginia Tunnel and Mining Company, as Daney Canyon lies below Silver City. Recently the author was shown the portal of the Daney Tunnel by F. N. Dondero, of Carson City, who has mining property in that area and who probably hauled in the last ore milled at the Sutro Mill prior to shutting down its operation. The ceiling of the portal is crushed down and overgrown with brush; a small stream of water was coming out at the time of our visit. Any history of the Sutro Tunnel would be incom- plete without at least a short discussion of colorful Adolph Sutro, the tunnel's instigator and builder. Adolph Heinrich Joseph Sutro was born in Aachen, Prussia, April 29, 1830. At the age of 20, he, along with his family, sailed for New York. After a few months he left his family in New York and sailed for San Fran- cisco, arriving there November 21, 1850. Within 4 years he owned several stores in San Francisco, dealing pri- marily in imported tobaccos. In 1859 he made his first trip to the "Washoe country" and was greatly impressed by the Comstock, then in its infancy. While there, he came to the conclusion that he could invent a better way to treat quartz ore. With the help of a chemist, he de- veloped a process which they were confident would work.* In about 1862 Sutro again went to Washoe (Virginia City) to look for a place to establish a reducing mill. He found a good mill site at Dayton, and by 1863 he had a substantial establishment there, with eight stamps and 20 amalgamating pans." It was during this period that his thoughts developed pertaining to a long tunnel to drain the mines on the Comstock. The matter of running a long tunnel to the Comstock Lode at a lower depth with an outlet near the Carson River was the subject of a great deal of discussion and editorial comment during the early days of the Com- stock. Adolph Sutro, while probably not the originator of the idea, supported a plan and immediately pro- ceeded to promote it. The obstacles confronting Sutro appeared to be almost insurmountable, but not to him. He was a combination of many things: a dynamo of WATER-RELATED EVENTS, energy, a great promoter, a great speaker (although he spoke broken English), and a fighter. He was hated by many, and loved by others. His proposed project involved the drilling of a tunnel 20,000 feet long starting near the toe of the range of hills westerly from Dayton, and with the mouth of the tunnel about 150 feet in elevation above the Carson River. The plans called for the tunnel to cut the Com- stock Lode about 1,600 feet below the surface. The Sutro Tunnel Company was incorporated by an act of the Nevada State Legislature, approved Febru- ary 4, 1865. This act granted an exclusive franchise to construct and operate the tunnel for a period of 50 years. Other provisions were that the mouth of the tunnel was to be located between Corral Canyon and Webber Canyon, that shafts were to be sunk along the course of the tunnel, and that the tunnel was to be started within 1 year from the passage of the act and completed within 8 years. Neither of the latter two pro- visions were met. At that time the title, or fee, to the land was in the United States Government, and an act of Congress was necessary to enable Sutro to obtain the necessary ease- ments. Sutro visited Washington and obtained the sup- port of Senator Stewart, and on July 25, 1866, a bill, commonly known as the Sutro Tunnel Act, was ap- proved, which became the first Federal law to provide for a location and patenting of mining claims on public lands. The Act, in addition to other provisions, em- powered Mr. Sutro to purchase 4,357 acres of land at the tunnel mouth and to claim ownership of the mines within 2,000 feet on either side of the tunnel, excepting, of course, the mines on the Comstock Lode.* Mr. Sutro was able to secure contracts in April 1866 from 23 of the principal mining companies, which rep- resented 95 percent of the stock-market value of the Comstock Lode at the time. By these contracts the com- panies which signed the articles of agreement bound themselves to pay the sum of $2 for every ton of ore ex- tracted after the extension of the tunnel and its lateral drifts had reached designated points.** A survey of the tunnel was made by our old friend Schussler, and work commenced on the tunnel October 19, 1869.+5 The surface survey was marked with cast iron posts. Each post was firmly placed in the ground and its top was weighted. A circular hole was machined in each top and a brass plug 11/4 inches in diameter inserted. The posts marked the course of the tunnel and were referred to as "The Line." ** The tunnel was completed July 8, 1878, a construction period of 8 years, 8 months and 19 days. On that day a connection was made with a short east drift from the 1861-1894 38 Savage mine at a depth of 1,640 feet. The length of the tunnel as finally completed was 20,498 feet and for the greater part of the distance the tunnel, inside the tim- bering, was 7 to 714 feet in height, 8 feet wide across the top, and 9 to 914 feet across the bottom. Lateral tunnels to drain the various mines along the Lode were then started; in the course of several years the north lateral, 4,403 feet in length, reached the Union shaft, and the south lateral was extended 8,423 feet to the Alta shaft. It was planned to construct four vertical shafts along the line of the tunnel, so that the excavation of the tun- nel could be carried on at eight different faces. These shafts were located in November 1871. The first was 4,915 feet from the mouth of the tunnel, at a vertical distance of 522 feet above the tunnel level; the second was 4,150 feet farther along, and its depth to the tunnel level was 1,041 feet; the third shaft was 4,490 feet from the second one, and its depth to the tunnel level was 1,361 feet. The fourth shaft was 17,695 feet from the tunnel entrance. In addition to the four shafts, a small air shaft was completed in the summer of 1872. It was situated 2,250 feet from the tunnel mouth, and had a depth of 211 feet to the tunnel level.*" Difficulties with water in both the third and fourth shafts caused them to be abandoned. In the first shaft, after 18 months of labor the tunnel level was reached, and drifts both east and west were started, the former in due time connecting with the tunnel header. At the second shaft, water was encountered, and pumps had to be placed in position. The tunnel level was reached in the spring of 1874. East and west drifts were then started, and when the former had reached a distance of 171 feet and the latter 170 feet a large body of water was encountered, filling the tunnel and shaft with water. This caused a delay of several months, but eventually work was resumed on the headings." During the first 5 years progress on the tunnel was slow. The monthly distance completed averaged 105%, feet in 1873 ; in 1874 2231, feet per month. At the close of 1874 some 8,079 feet of the tunnel had been com- pleted. In 1874 Burleigh Drills, operated by compressed air, were put in use, and this greatly speeded up the work. In 1875 the tunnel advanced 3,728 feet, and the average footage completed per month increased to 310% feet. As heretofore stated, the tunnel made a connection with the east drift of the Savage mine on the 1,640-foot level. On July 8, 1878, the Savage mine water, which heretofore had to be raised 2,200 feet to the surface, had then only to be raised 600 feet to the tunnel level." It is interesting to note that during the early history of the tunnel horses were tried for pulling the cars 34 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK iggy, FrGurRE 19.-Mules used in the construction of Sutro Tunnel. Courtesy of Nevada Historical Society. loaded with waste rock. However when anything touched a horse's ears, the horse would throw up his head, hitting the overhanging rock and hurting his skull. Mules, on the other hand, would drop their heads and avoid injury (fig. 19).5° The cost of the tunnel was $2,096,566, not including the cost of the laterals or expenses of management of the company." The laterals, amounting to about 12,800 feet of tunnel 8 feet in width by 7 feet in height, probably cost another million dollars. Thompson & West state that the cost of the tunnel itself was about $4,500,000 and the total cost, including lateral branches up to and including March 1, 1881, was Sutro had many supporters among the mine owners, including William Sharon, during the early construc- tion period ; however, later on disputes arose, and a bitter fight broke out between the two. The mine owners re- fused to pay the royalty of $2 per ton of ore mined, and Sutro was forced to reduce the royalty to $1 a ton. Shortly after this he sold out and retired to more pleasant activities at San Francisco. Eliot Lord states that in 1880 the tunnel drained some 3,500,000 gallons of water daily and that during the year 1,277,500,000 gallons of water, or 4,752,605 tons, drained through the tunnel. Much more was ex- pected after the laterals were fully completed." During the 50 years following the completion of the tunnel and its various laterals, the Gold Hill mines, with hot waters of 150°, were automatically drained through the Sutro Tunnel. In the Virginia City mines, the water stood about 100 feet below the tunnel after 1884, except for a brief period after 1900, when the north end mines were pumped out to the 2,500-foot level." In 1872 Sutro laid out a townsite near the mouth of the tunnel, which he named Sutro. It was to be a model town, with the main east and west thoroughfare, named Tunnel Street, lining up with the tunnel. This street was to be 200 feet wide ; the other east-west streets were 80 feet in width. The avenues, which ran from north to south, were named for women, from Adele through Jeanne, and were 100 feet wide, except for Florence Avenue, which had a width of 150 feet. Four 11-acre parks were laid out, and the plans called for board side- walks. A large steamboat Gothic style house was built for Sutro at company expense near the mouth of the tunnel; the structure cost $40,000 to build and fur- nish (fig. 20) ." When the author first came to Carson City in 1985, this great mansion still stood, as well as the mill which had been constructed to process ores coming through the tunnel. The mansion burned in the 1940's, and the mill was destroyed by fire in 1967 (fig. 21). WATER-RELATED EVENTS, 1861-1894 35 (é Seaue £500 Pert rere Inch TOWN or SUTRO - AND OTHER PROPERTY BELONGING TO THE sUTRO TUNNEL Co Lyon County, Nevada. cote mummers. mwhhfln'fludw are b Wack han and o dist e Ty muah y vl wib dig Goby fel vido Grade from rnb f ena o Carian Kew Dna nde ily fot Explanations Sutre Tinaet (at Land _ thous thu - - - ~ \ i B Surveyed and drawn m & . \A \x! Ress £ Brome . *i} [=] Freur® 20.-Map of the town of Sutro, 1873. The description reads: "Lands belonging to the Sutro Tunnel Company are enclosed by black lines and are divided into squares represent- ing forty acres each. Each town block is three hundred feet square and consists of twenty-four lots 25 x 130 each. Avenues Where the mansion once stood, only the foundation remains. The reservoir, in front of the mansion, is now just an ugly depression, with fallen trees, tin cans, and other debris. The writer on a recent visit was saddened by the conditions of the tunnel portal. Trees and brush almost obscure the portal, and back of the concrete fac- ings, the tunnel is caved in for about 50 feet. Only a are one hundred feet and Streets eighty feet in width, with alleys between the blocks forty feet wide. Grade from mouth of tunnel to Carson River one-hundred & fifty-five feet." Scale of the reproduction above is approximately 1 inch=10,000 feet. small stream of water flows out of the tunnel now ; this water comes from a spring in the tunnel itself. The mine drainage waters are dammed off by slides deep in the tunnel. Glancing back of the tunnel portal and follow- ing the alignment of the tunnel up the hillside, the heavy cast iron posts heretofore mentioned are still in place. On the ones observed, the brass plugs are gone. 36 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK Freur® 21.-Sutro's mansion about 1874 near tunnel portal. Courtesy of Nevada Historical Society. In 1879 Adolph Sutro resigned his position as Super- intendent of the Company and moved his activities to the San Francisco Bay Area, where he remained until his death in 1898. He sold his stock in the Sutro Tunnel Company for $709,012." By so doing he became the only man who ever made any appreciable amount of money from that project. He invested his money in property in San Francisco, and became a very wealthy man. Although he was unsuccessful in his attempts to become United States Senator from Nevada, he was elected Mayor of San Francisco in 1894 (fig. 22). An article concerning the Sutro Tunnel which ap- peared in the December 4, 1909, issue of the Goldfield News stated that- Yesterday was marked by an important event in connection with the repairs under way in the Sutro tunnel. The steam-tight, stovepipe drain which has been underway for the past three or four years, was practically completed. The finishing of this pipe has been one of the main features of the new work in the tunnel, and the latter is now cool in its entire length, making rapid progress possible for the bal- ance of the work to be done in the tunnel. The Savage Mining Company is now running the Comstock Tunnel Company's mill at the mouth of the tunnel to full capacity and ore is being shipped daily through the tunnel to the mill. A new track has been built practically throughout the tunnel and a large amount of transportation is being han- dled early and without delay. The drainage facilities of the tunnel are now per- fect to take care of the large increase of water being sent through from the C & C shaft. The pumping is being steadily increased every day and more water is now being raised from the lower levels than at any time since pumping was resumed some years ago. Mrs. Jack Greenhalgh of Virginia City, who is the daughter of Tom Higgins, foreman for the Virginia and Gold Hill Water Company from 1906 to 1937, remembers being told by her father that many Dayton and Sutro people would go to Virginia City for Satur- day night dances by means of the Sutro Tunnel, reach- ing the surface at Virginia City by riding up the C & C shaft. Mrs. Greenhalgh also recalled that as a small girl she would ride on the four-horse wagons hauling ice from the storage house at Five Mile Reservoir to the mines. She would then be allowed to ride down the shafts in the hoist cars loaded with ice for the use of WATER-RELATED EVENTS, 1861-1894 37, the miners working in the unbearably hot atmosphere of the deep tunnels. Jack Greenhalgh, who has been with the Nevada State Department of Highways for more than 35 years, told the author that in the 1930's he took a leave of absence from the Highway Department and, with a partner, operated the Comstock Mill located at the mouth of the Sutro Tunnel, milling mostly custom ore. The Comstock Tunnel and Drainage Company and the Sutro Tunnel Company have their offices in San Francisco. The latter company still owns the property adjacent to the portal of the tunnel, and so far as is known still owns the easement for the tunnel granted by Congress in 1866, as well as other properties in the general area. Water Power and Electric Power "Nowhere else on the face of the globe is there any- thing of the kind that approaches it." Thus the water- power development scheme at the C & C shaft was de- scribed by the Territorial Enterprise of September 30, 1887. The article referred to the development of water power in the California and Consolidated Virginia companies' joint shaft to operate the large stamp and pan mills. Water for the project was obtained from the Virginia and Gold Hill Water Company. A large tank was con- structed near the flume line, capable of holding 80,000 gallons of water. Water was conducted through an iron pipe which varied in diameter from 20 inches at the tank to about 12 inches where it went down the C & C shaft. Both the tank and pipeline, which was about 3,000 feet long, were designed and constructed by Captain Overton. At the ground surface near the C & C shaft, the water, under considerable pressure, hit a 11-foot Pelton Wheel, which by means of pulleys and cable, ran the 80 stamps of the battery mill and also 12 Boss grinding pans. A Pelton Wheel is similar to a water wheel used to raise water a few feet from a ditch or stream. The differ- ence in this instance is that the Pelton Wheel was used to develop power. As will be seen, the Pelton Wheels at the Chollar shaft ran dynamos which produced elec- tricity to operate the mill, whereas at the C & C shaft they produced mechanical power. Water under pressure was forced against the cups of the Pelton Wheel, caus- ing them to revolve. The speed of the wheel was gov- erned by the amount of water and pressure. The amount of water used at the C & C shaft was about 1,700 gallons per minute under a pressure head of about 580 feet. After the water was used on the Consolidated Vir- ginia's surface Pelton Wheel, it was dropped down the FiGurE 22.-Adolph Sutro. Courtesy of Nevada Historical Society. C & C shaft, where it was passed through three other Pelton Wheels of the same size, spaced 500 feet apart vertically. The Territorial Enterprise of September 30, 1887, de- scribed the workings in the shaft as follows: There is a great deal more of machinery in the shaft to conduct the power to the surface than there is on the surface to conduct it to the mill. It is an entirely different system of transmission. It is the only system of perpendicular transmission of power upon the face of the earth, and the men who planned it and carried it out are the inventors of it-they are the argonauts. The stations are num- bered "A," "B," "C," "D,": the last being at the Sutro tunnel level, and the first on the surface-all being 500 feet apart, and there is a Pelton wheel on each station. From A to B there are three wires or cables from B to C two wires, and from C to D, one wire. The stations are forty feet in depth, and the face is fully twenty feet high to make room for the 38 THE STORY OF THE WATER bearing wheels. At each station there are grooved wheels upon which the wires run. There is a system of water gauges at the surface and at each station. There are six small water pipes that run from A to B, four to C and two to D. By turning the water on or off at the surface in these small pipes, gates are either opened or shut which gauges the water that is played on the Pelton wheels at any station desired-that is to say, that any of the Pelton wheels or all of them can be stopped or regulated at will from the surface. . . . The water was first played from an inch nozzle, and strikes the cups of the Pelton wheel underneath it and flows back into a tank. . . . Any size nozzle can be put on from one to two and a half inches, according to the power desired to be played upon the wheels. The stream that comes out of an inch nozzle is nearly as rigid as a bar of iron. From the first tank the water is conducted down the shaft, makes a curve at the sta- tion and is played under the wheel in the same man- ner as the first, and so on to the Sutro tunnel where it escapes. The pan mill was located about 1,000 feet from the stamp mill, and between the two there was a depression. Pole lines were erected to the pan mill, and cables or wire ropes were installed above the ground which were a part of the intricate series of Pelton Wheels, pul- leys, cables, etc. operated by water power from the water company flume. To someone seeing such an installation in the present day, it would appear to be a rube goldberg affair. How- ever, in the 1880's it was recognized as a great engi- neering feat-which it was. The reader might be confused as to how the shafts could be sunk or worked in with all the equipment which was installed, such as the Cornish Pumps, the hydraulic pumps, and the Pelton Wheels. The C & C shaft was the first of the great third-line shafts. Such shafts had four compartments (except the Forman shaft, which had five) : one for the pumps, another for sinking the shaft, and two for hoisting."" Later all the deep shafts were of this type. The first mill on the Comstock to use electric power was the Nevada Mill, built in 1887, which had 60 stamps, each weighing 800 pounds, 30 amalgamating pans, 15 settling pans, and 10 agitators." The power to operate the mill was run both by water power and by electricity. The Territorial Enterprise of September 21, 1887, stated : The ten-inch pipe to conduct water for the water- wheel at the mill and the electric plant is nearly complete. The work is under the supervision of Cap- tain Overton and the pipe that is being used is ten inches in diameter and will first be used to run the 11-foot Pelton wheel at the mill and until it is needed down the Chollar shaft will run down Six Mile Canyon. SUPPLY FOR THE COMSTOCK The electric plant, as described by Grant Smith, con- sisted of six 40-inch Pelton Wheels set up in a large chamber at the Sutro Tunnel level." After the water, under a 460-foot head from the water company's flume above, was used on the 11-foot Pelton Wheel at the surface, it was flumed a short distance to the Chollar shaft and was dropped vertically through two large iron pipes to six Pelton Wheels. The vertical drop was 1,630 feet. Each wheel drove a dynamo, and the con- trols were so arranged that any number of the six dynamos could be run at one time. The power was then transmitted up the shaft to the mill. The Territorial Enterprise further commented that "never before has any water wheel been operated under a vertical pressure of 1,630 feet." The type of power used here and at the Yellow Jacket in the Gold Hill section to operate the mills was prob- ably not too widely used on the Comstock, steam power being the mainstay until electric power was brought in from a powerplant on the Truckee River, 40 miles away, about 1900. The author has briefly described the water power developed at the Nevada Mill to illustrate the resource- fulness of the Comstock miners. This description, cou- pled with that of the operation of the large Cornish Beam Engines and Pumps, and the hydraulic pumps, should give some idea of the magnitude and complexity of at least some of the outstanding operations on the Comstock. Electric Lights The Virginia Gas Company was organized early, and the Virginia City streets and business houses were lighted with gas. Illumination in the homes was fur- nished by kerosene lamps, which continued in general use until electric power was brought in from the Truckee River about 1900. However, electric lights were used in many of the mills, business houses and on the streets as early as 1888. The Territorial Enterprise of December 2, 1887, stated that : Our light is no longer "hidden under a bushel" in this city set upon a hill. It blazes forth to the illumination of all, and is the light that flashed down from the heavens long before man was on the earth. It is the light that always will be, and can never be improved upon. The Enterprise article went on to say that the Vir- ginia City Electric Light Company was formed and was headed by W. S. Hobart and Alvinza Hayward, with Captain J. B. Overton as Superintendent and Manager. The works of the electric company were located close to the new water mill of the Nevada Mill & Mining Company, just in front of the Chollar hoisting works. WATER-RELATED EVENTS, 1861-1894 39 Water was piped down from a reservoir on the side of Mount Davidson, 460 feet above the hoisting works. The reservoir in turn received its supply from the Vir- ginia and Gold Hill Water Company flume. The dy- namos were driven by water power from three small Pelton Wheels, working under a pressure of 200 pounds to the square inch. The Pelton Wheels were 161%, inches in diameter, and each wheel drove one dynamo. The Enterprise article, commenting on the prices charged for electric lights in Virginia City, stated the charges would be the same as those of the California Electric Light Company in San Francisco. The December 4, 1887, Territorial Enterprise stated that for the first time several electric lights were in use along "C" Street. Most of the lights were in business places. The first outside electric light ever installed on "C" Street was that in front of the Vucovich Brothers' Magnolia Saloon and "Mr. Armer's Cigar Store." In commenting on the electric lights, the E'nterprise re- porter had this to say : "The lamps gave a very brilliant and steady light. Beside it, ordinary lights-coal oil or gas-look pale and sickly. The electric light could be observed by persons distant two or three blocks, as a white radiance pervaded the atmosphere for a large surrounding area." Doubtless some of the homes in Virginia City in- stalled electric lights prior to the power being brought in from the Truckee River. These installations were probably limited, because of the small capacity of the plant and the cost of electricity as compared with that of the kerosene lamp. It is of interest to note that electricity for the water company's Lakeview house was furnished for many years by a small Pelton Wheel placed in the 1875 pipe- line which ran beneath the kitchen. Red McGovern told the writer that the wheel was removed about 1957. Pumping Water From Deep Shafts A number of shafts on the Comstock reached and even exceeded a depth of 3,000 feet from the surface. Among these were the Combination shaft, which reached the greatest depth, 3,250 feet ; the Crown Point- Belcher; the Hale and Norcross and the New Yellow Jacket reached depths about 3,000 feet. Several others reached 2,500 feet in vertical depth. It is interesting to note that the bottom of the C & C shaft was more than 1,700 feet lower than Carson City. As previously mentioned, getting, rid of the mine water was one of the great problems confronting the mine operators. Many of the deep shafts of different companies were connected, and additional trouble devel- oped when one or more of the companies was lax in pumping water from their shafts. This threw a greater burden on those who did. However, the water problem could be handled, especially after the Sutro Tunnel laterals reached the various mine shafts, because this reduced the pumping level on an average of about 1,600 feet. The greatest problem, and one which could not be successfully overcome at that time, was the high tem- peratures in which the miners had to work. Temperatures increased with depth, and the miners worked in adits and shafts where temperature was as great as 134°F. Springs of hot water were often en- countered with temperatures as high as 157°F. In the Crown Point mine, 2,000 feet below the surface, the temperature was 150°F., and it was only 16° less in the open drift." Large volumes of air were pumped in the mines, but because of impaired air circulation, the problems were still acute. Tons of ice were sent down daily into the mines. Ninety-five pounds of ice were consumed daily by each miner employed in the hottest workings of the California and Consolidated Virginia mines during the summer of 1878. While the problems of heat and water were the main causes of the cessation of deep mining, there were other factors involved. No bonanzas had been found during the 10 years of deep mining, 1876-1886, and the great expense involved, together with the fact that $40 million had been expended in those 10 years by mines which did not pay any dividends, finally brought an end to large- scale deep mining on the Comstock." All the deep mines ceased to operate between 1882 and 1886. The New Yellow Jacket shaft in the Gold Hill section, which had reached a depth of 3,000 feet, shut down in March 1882. The north end mines (the Con- solidated Virginia, California, Ophir, Mexican, Union, and Sierra Nevada) were the next to stop pumping, near the end of 1884. The Alta shaft below Gold Hill and the Forman shaft followed in December of that year. The manner in which the mine operators pumped water from the deep shafts in order that they could be driven to even greater depths is interesting; it is certain that the reader will be impressed at the ingenuity of these Comstock mine operators. At first, and in the shallow shafts, buckets were dropped by means of a windlass and, when filled with water, were hauled out by manpower. Later, as the workings deepened, a larger bucket was fastened on the bottom of the ore bucket, lowered to a water sump, and hauled up with the ore by steam engines. As the amounts of water increased, improved methods had to 40 THE be used. Plunger pumps run by small steam engines were used between 1861 and about 1874. Probably, as the depth of the shaft increased, more than one plunger pump was used in the same shaft; one pump pumping to a certain level, from which the water was pumped to a higher level by another pump. As depths increased, the water increased in volume and larger pumps had to be installed. This brought about the advent of the Cornish Beam Engines and their pumps. These pumps served their purpose until about 1881, when the new hydraulic pumps were installed. The Cornish Beam Engine, or Cornish Pump as it was familiarly known, was so named because it was de- veloped by the Cornish people in Cornwall in the mid- 1800's to dewater their deep copper mines. The Cornish miner (commonly known in America as Cousin Jack) played an important role in the early mining develop- ment in the Western United States. In essence, the Cornish taught Americans the technique of hard-rock mining. One of their contributions was the introduc- tion of the Cornish Pump to the Comstock and to many other deep mining areas in this country. Victor Goodwin gives a good description of the Cornish Miner, and also the Cornish Beam Engine, in Nevada's Northeast Frontier." Probably the first Cornish Pump was installed on the Comstock in the early 1870's. The last one built was in 1879, at the Union shaft (fig. 23)." As it is rather difficult to describe these huge machines, one good contemporary source will be quoted. The pump at the New Yellow Jacket vertical shaft, 3,080 feet deep, has a capacity of 1,000 gal- lons a minute, or 1,440,000 gallons in twenty-four hours, and regularly raised over 1,000,000 gallons. The pump rod was 3,055 feet long, made of lengths of Oregon pine, 16 by 16 inches, strapped together with iron plates. Its weight when in motion was 1,510,400 pounds. Its greatest capacity was seven strokes a minute, each stroke lifting 160 gallons. The weight of the pump rod was equalized by 8 balance bobs placed at intervals in the shaft, carrying a total lifting weight of 240 tons. There were 13 pumps in the shaft placed at intervals of about 250 feet, which lifted water from station to station, all attached to the pumping rod. The two fly wheels weighed 125 tons. ® The Mining and Scientific Press of July 17, 1880, carried a very vivid article on this Yellow Jacket Cornish Pump. In this article, the reporter stated : "This machinery is regarded as a remarkable triumph of mechanical skill, and we spare space for the follow- ing description of it from the Territorial Enterprise." The article goes on to describe some of the pump's features, which will be briefly covered here. The pump STORY OF THE WATER SUPPLY FOR THE COMSTOCK rod, more than 3,000 feet long and made up of 16 x 16- inch lengths of Douglas-fir (then colloquially known as Oregon pine) securely bolted together, passed through "stays" that were placed across the shaft compartment every 30 feet to prevent vibration. There were, in addi- tion, six rod-catchers to prevent the massive wooden pump rod falling down the shaft if it should break at any place. The balance bob was a long beam of wood or iron resting on a fulcrum near its center. On the outer end was a large wooden box capable of holding many tons of iron ballast. At the inner end of the beam, there was a huge iron clevis that was attached to the pump rod. The clevis was so attached that the swinging or rocking motion of the bob, which described part of the circumference of a circle, would impart a vertical movement to the pump rod. The pump column was an iron pipe 14 inches in di- ameter running the full depth of the shaft. In order to support the column, a number of large collars were sup- ported by the heavy timbers. The article points out that at that time there were six pumps in the Yellow Jacket shaft above where the south lateral of the Sutro Tunnel tapped it. After this connection was made these pumps were no longer necessary. It is hard to visualize a tim- ber shaft 16 inches by 16 inches square and more than a half mile long operating 13 pumps. The article con- cludes by giving this description : The simultaneous starting up of a line of pumps 360 feet over half a mile in length is truly a most remarkable achievement and a feat that has never before been performed or attempted in any part of the world. When the big engine made its first revo- lution, all this half mile of pumps made a stroke. Not only was the whole pump rod of 300 tons moved but a great weight of water was also lifted. Great credit is due Mr. Pyen, who placed in posi- tion #1} the 13 pumps, 8 bobs and many other parts, for the patience, skill and excellent judgment dis- played. A very little thing out of place at any one point would have caused a grand smash-up of everything. All the deep shafts used the Cornish Beam Engine, and in many cases hydraulic pumps were added to as- sist. At the Combination shaft, there was a double line of Cornish Pumps, in addition to hydraulic pumps. Altogether the pumps lifted 5,200,000 gallons of water every 24 hours to the Sutro Tunnel level. On October 16, 1886, these pumps ceased to operate. The last Cornish Pump installed on the Comstock was at the Union shaft in 1879. The flywheel was 45 feet in diameter, and the pumping beam was 48 feet between centers. The pump rod had similar dimensions to that used at the Yellow Jacket, but was 2,500 feet long. Here, as at other shafts, the water was not WATER-RELATED EVENTS, 1861-1894 41 1 \ A 23.-The last Cornish Pump on the Comstock, installed at the Union shaft in 1879. It had a 45-foot flywheel weighing 110 tons. Courtesy of Nevada Historical Society. pumped directly from the bottom to the top of the shaft, but in stages from one tank to another on differ- ent levels. Each tank had a separate pump connection with, and was operated by, the main pump rod. Some idea of the great size of the Cornish Beam Engines may be formed when it is stated that the sta- tions excavated for them in the shafts were 85 feet long, 28 feet wide, and 12 feet high."" The hydraulic pump was a late innovation on the Comstock to supplement the huge Cornish Pumps. They were first introduced in the early 1880's. The hydraulic pump installation at the Combination Shaft is described by DeQuille." He states that at the 2,400- foot level two Cornish Pumps had been in opera- tion and handled the water until a drift encoun- tered additional water which the Cornish Pumps could not handle. It was at this time that the management installed a hydraulic pump. This pump was operated by the pressure of water from the surface. The pump merely consisted of a 12-inch iron pipe running down the shaft, and in the case of the Combination shaft, to the 3,000-foot level. At the 3,000-foot level the end of the pipe was turned upward 180°, forming a U shape- the last few feet being tapered down and fitted with a nozzle. The water was obtained from the Virginia and Gold Hill Water Company's flume, and was conveyed from the flume by a pipe and then dropped down the shaft in the 12 inch pipe. At the Combination shaft the end of the upturned section was fitted with a one- inch nozzle made of phosphor-bronze, through which the water was ejected into a larger discharge pipe, both being submerged in the water sump. The tremendous pressure developed by the water falling more than 3,000 feet (about 1,300 pounds per square inch) and passing through the small nozzle, together with the suction it created, forced the water in which the pipes were submerged upward to the Sutro Tunnel level where it was discharged into a lateral lead- ing to the Sutro Tunnel. The lift was about 1,400 feet. DeQuille states that when one stood at the 3,000-foot level and looked up a compartment of the shaft, 5 by 6 feet in size, the little spot of daylight seen at the top appeared to be about 4 inches square. * The installation of the hydraulic pump, or elevator, as it was sometimes called, was rather simple and not too costly. Davis states : Using water under such great pressure brought forward problems in hydraulics not yet solved. The advantages of the system were so great as to economy of space and first cost that every feature of the system deserves the most careful study. Before a hundred thousand dollars had been ex- pended in this system, more water was discharged into the drain tunnel at one time by it than had been discharged by the five million dollars worth of pumps formerly in operation on the Comstock Lode. * 42 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK THE TWENTIETH CENTURY Any description of the water-supply system for Vir- ginia City, Gold Hill, and Silver City would not be complete without tracing its history up to the present time. The system reached its greatest magnitude at the time the third pipeline was put in operation in 1887, at that time had a capacity of nearly 10,000,000 gallons of water daily to the Five Mile Reservoir. The main task of the Virginia City Water Company in later years was to keep the system in operating condition, which at times during severe winter weather was a task of considerable magnitude. In 1906 Mr. J. B. Overton, Superintendent of the water company from its inception, retired. He was at that time over 80 years of age, and had also served as Superintendent of the Sierra Nevada Wood and Lum- ber Company, as well as being engaged in other activi- ties on the Comstock. His place as Superintendent of the water company was taken over by Mr. James M. Leonard (fig. 24). Mr. Leonard had started working for the company in 1901 and continued in that capacity until 1959. He was related by marriage to W. S. Hobart, who had been one of the principal owners of the water company, as well as the Sierra Nevada Wood and Lum- ber Company. The author was well acquainted with Mr. Leonard, who was recognized as one of the outstand- ing citizens of the State. In about 1940 he turned a great portion of the operation of the system over to his son, Hobart Leonard, who became Superintendent and President of the water company following the death of his father in 1959 (fig. 4). Red McGovern, who started working for the water company in 1934, was first employed as a helper to the attendants at the various stations on the system be- tween Marlette Lake and Five Mile Reservoir (fig. 25). Red recalls that there were stations at Marlette Lake, Hobart Creek, The Tanks, West Tunnel Portal, Lake- view, Five Mile Reservoir, the Divide between Vir- ginia City and Gold Hill, and the pump tanks in Vir- ginia City. In addition, the company maintained its headquarters in Virginia City. The water company had its own telephone line, so that the attendants at the var- ious stations could remain in touch with each other and also with the main office in Virginia City. Mention should be made of two men who, prior to Red McGovern's service with the water company, played an important role in the operation at the Sierra water system: Tom Higgins and Joe Ber- ger. Mr. Higgins, who was foreman under James Leon- FiGUrE 24.-James M. Leonard, Superintendent of the Virginia and Gold Hill Water Company from 1906 to 1959. Courtesy of Hobart Leonard. ard, first served as attendant at Red House, the Station of Hobart Creek (fig. 1). In 1899 he moved with his family to the Lakeview house, and in about 1906, moved to the Divide station between Virginia City and Gold Hill. He finally retired in 1937."° Following Mr. Hig- gins' move to the Divide station, the Lakeview house was occupied by Mr. Joe Berger and his family. Mr. Berger had previously been the attendant at The Tanks (fig. 2)." On April 17, 1922, the Virginia and Gold Hill Water Company deeded all its rights in the entire water sys- tem to The Virginia and Gold Hill Water Company. On April 21, 1933, the Virginia and Gold Hill Water Com- pany deeded to The Virginia City Water Company. THE TWENTIETH CENTURY 43 Curtis-Wright Corporation The Curtis- Wright Corporation purchased the Sierra water system, together with all its water rights, lands, easements, etc., up to the meter box a hundred feet or so northerly (toward Virginia City) from the Five Mile Reservoir. The deed was conveyed on August 8, 1957. The Curtis-Wright Corporation was then planning a large missile-testing program in Storey County, under a Government contract. This company, by exchanges and purchases, acquired title to about 95 percent of the lands in Storey County, which it still owns (1969). About the only lands not acquired were the townsites of Virginia City, which is the Storey County seat, and Gold Hill. The program, as planned by the company, involved the use of a large and stable supply of water. At that time the future of the Virginia City Water Company, as well as its water supply, was somewhat uncertain, as the de- mand for water in Virginia City and Gold Hill was quite small and the water company was having financial troubles. Curtis- Wright, therefore, felt it necessary to purchase the water company's Sierra water system in order to carry out its anticipated program in Storey County. In addition to the Sierra waters owned by the Virginia City Water Company, the Curtis- Wright Cor- poration purchased several decreed water rights on the Truckee River. Between the years 1956 and 1959, the cor- poration filed five applications with the State Engineer to change the points of diversion, manner and place of use of the purchased Truckee River waters. The water was to be conveyed to a reservoir site in see. 27, T. 19 N., R. 21 E., about 12 miles north of Virginia City, and was to be used for industrial and domestic use. The corporation also planned to pipe a portion of the Sierra water from Five Mile Reservoir through Vir- ginia City, and thence northward down Long Valley to the reservoir site in said sec. 27. About 1941, the Virginia City Water Company, under the direction of Hobart Leonard, had started removing the first pipeline (1873) and the third pipeline (1887) in the inverted siphon, and using the pipe to replace the flumeline from Five Mile Reservoir to Virginia City. This operation was not completed until the mid- 1950's (fig. 4). On December 2, 1957, the Curtis-Wright Corpora- tion deeded all its rights in the water system to the Marlette Lake Company, a wholly-owned subsidiary of Curtis- Wright. Shortly after acquiring title, the Marlette Lake Company started a program of improving the water system. In 1959 Marlette Lake Dam was raised 15 feet, FreurE 25.-Harry E. "Red" McGovern, Water Master of water- works between Marlette Lake and Five Mile Reservoir, He has spent 35 years on the Sierra system. increasing the capacity of the reservoir from 2,000,000 gallons (6,154 acre-feet) to 3,400,000 gallons, or about 10,400 acre-feet. The Hobart Creek Reservoir Dam, which had partially washed out in the December 1955 flood, was repaired in 1956, before the purchase by Curtis-Wright. A new 8-inch pipeline replaced the single remaining box flume from the outlet of the siphon to Five Mile Reservoir. This line was put in by Curtis- Wright in February 1957, just before it pur- chased the system. The flumeline from Marlette Lake Dam to the west portal of the tunnel had long been in disrepair, and the company was planning to replace this section with a pipeline and repair the tunnel. Even though no water was coming to the tunnel from Marlette, the tunnel itself actually producing an average of 400 gallons of water per minute. As late as 1964, this water was still being conveyed by the old box flume to Hobart Creek, to- gether with other waters collected along the way. According to Edward Kruse, former Superintendent of the Department of Buildings and Grounds for the - State of Nevada, and the Carson City Water Company entered into a contract in 1959 with the Marlette Lake Company to purchase up to 3 million gallons of water per day. The contract with the State of Nevada had a maximum of 1 million gallons per day, and the Carson 44 THE STORY OF THE WATER City Water Company could purchase up to 2,000,000 gallons daily. Also, the Virginia City Water Company had a contract to purchase water not to exceed 300,000 gallons per day. In 1961 the water used in Virginia City, as recorded by the meter at Five Mile Reservoir, was 50,864,000 gallons, or an average of 140,000 gal- lons per day. In 1962, the use was 63 million gallons, or an average of 175,000 gallons per day. Mr. Jac Shaw, in 1968 the Superintendent of the De- partment of Buildings and Grounds, informed the author that the present use by the Virginia City Water Company varied between 220,000 gallons per day dur- ing the winter months and 750,000 gallons per day dur- ing the summer months, and that the State used about 100 million gallons during the peak summer months of 1968. Franktown Irrigation Company Another chain of events, starting in 1946, concern the water conveyed by the old Virginia and Gold Hill Water Company's north flume from Third Creek and the Franktown Irrigation Company ; it should be told. The Franktown Irrigation Company is composed of a group of ranchers on the west side of Washoe Valley and southerly from Bowers Mansion, whose lands have been irrigated by the waters of Franktown Creek since the late 1850's. Oftentimes the streamflow was not suffi- cient to irrigate all their lands. In order to increase their water supply, a dam was constructed at the lower end of Little Valley. This was probably during 1879. The Nevada State Journal of February 2, 1881, noted that the day before a huge flood had occurred on Frank- town Creek as the result of the dam failing. The flood waters, reaching crests of 25 feet, washed out all but six buildings in Franktown. The property loss was estimated to be $50,000. The Franktown Irrigation Company and the Vir- ginia City Water Company entered into an agreement for the purchase by the Irrigation Company of the water rights held by the water company on North Creek (Third Creek) and tributaries. Accordingly, on June 27, 1946, the Virginia City Water Company filed an application (No. 11624) with the State Engineer to change the point of diversion, manner and place of use of 5.5 cfs of the waters of North Creek. This was the major portion of the waters that the north flume con- veyed to the west portal of the water company's tunnel. The proposed point of diversion was about 114 miles uphill from the point where the water company's flume diverted water from Third Creek, and approximately 1,000 feet higher. SUPPLY FOR THE COMSTOCK Because of a protest filed against the application, a hearing was held on October 29, 1946. The writer, then Assistant State Engineer, held the hearing. The main witness was James M. Leonard, Superintendent of the Virginia City Water Company, who had acted in that capacity since 1906. He testified that from 1901, when he first went to work for the water company, up to 1944, the north flume to the west portal of the tunnel was in yearly operation, but no use was made of the flume in 1944 and 1945 because of the washing out of the diver- sion works. He added that when in operation the flume picked up water from other tributaries on its way to the tunnel. Mr. Leonard further testified that the water company had been decreed 75 inches of water under a head of 6 inches in 1892, and that W. E. Price was decreed 150 inches. Later, the water company purchased Price's de- creed rights of 150 inches, giving the company 225 inches of water. (This would represent a flow of 2,524 gallons per minute, or about 5.5 cubic feet per second.) The records of the State Engineer's office show that in 1939 the water company deeded 5 inches of water to Norman Biltz at Incline Lake, leaving them with 220 inches of water. Under the application the works of diversion would divert the water from North Creek (Third Creek) at points within the S%48%4, sec. 26, T. 17 N., R. 18 E., and then would convey the water through a ditch to be constructed approximately one-half mile to a point on Ophir Creek in Tahoe Meadows, a short distance northwesterly of the Mount Rose Highway. The water would then be conveyed by Ophir Creek to Price Lake, and rediverted by a ditch approximately 1 mile long to a tributary of Franktown Creek in Little Valley, where it would be comingled with the natural flow of Franktown Creek and used for irrigation purposes by the Franktown Irrigation Company. As a condition to having the application approved, the irrigation company stipulated that it would place a Parshall measuring flume at the point of diversion, and also one where the diversion ditch emptied into Ophir Creek and still another one where the water was rediverted from Price Lake. It was agreed that the Irrigation Company would assume a 10 percent loss of water in Ophir Creek and Price Lake, and that a water commissioner, approved by the State Engineer, would be engaged each season. On June 10, 1946, the Virginia City Water Company deeded application No. 11624 together with 5.5 cfs of the waters of North Creek to Henry E., Roy F. and Edwin Heidenreich, representing the Franktown Irri- gation Company. On July 24, 1947, the Heidenreich's deeded Permit No. 11624, together with the water rights, THE TWENTIETH CENTURY 45 to the irrigation company. Subsequently, on February 14, 1955, the State Engineer issued Certificate No. 4217 under Permit No. 11624 in the amount of 5.5 cfs of water to the Franktown Irrigation Company. The cer- tificate provided that the irrigation company could di- vert 1.9875 cfs of water during the months of June through December and 3.625 cfs during the months of January, February and May for the irrigation of 1969.39 acres of land. Because of snow conditions in the winter and spring at the higher elevations, the irrigation company very seldom is able to get the water from North Creek to Ophir Creek and from Price Lake to Franktown Creek until late in the spring of each year. As the company's diversion point is about 1,000 feet higher and 114 miles distant from the old water company diversion, it was not able to obtain the total water rights it purchased. However, this added supply of water, short as it may be at times, has been of great value to the Franktown ranchers. On September 14, 1951, the Franktown Irrigation Company, feeling that it should protect its vested rights to the waters of Franktown Creek, petitioned the State Engineer to make a determination of the relative rights to the waters of Franktown Creek and tributaries. The petition was granted, and the State Engineer proceeded with the adjudication. On July 11, 1960, a decree was issued by the Second Judicial District Court of Wa- shoe County. The decree granted the Marlette Lake Company 10 cfs of the water of Hobart Creek and trib- utaries above the Red House diversion and to the Frank- town Irrigation Company 37.09 cfs of the water of Franktown Creek below the Red House diversion." A certificate of water rights in the amount of 10 cfs was issued on June 5, 1967, to the Marlette Lake Company. It should again be pointed out that Hobart Creek and Franktown Creek are one and the same. The stream is generally called Hobart Creek above Red House, and Franktown Creek below. Purchase of the Sierra Water System by the State The next episode in the long and interesting history of the Sierra water supply for the Comstock involved the purchase by the State of Nevada of practically all the assets of the Marlette Lake Company. The Federal Government contract for the missile-testing program having failed to materialize, the Curtis- Wright people were no longer interested in their water-supply pro- gram, and desired to dispose of the Sierra water-supply system and its watershed lands. The sequence of events was as follows : On February 8, 1963, Mr. H. J. Knell, President, Marlette Lake Company, by letter addressed to Edward Kruse, Superintendent of Buildings and Grounds for the State of Nevada, offered to sell the assets of the Marlette Lake Company to the State for a price of $2 million. Mr. Kruse, in a letter to Governor Grant Sawyer dated March 15, 1963, recommended the purchase by the State. He pointed out that in 1959 the State of Nevada and the Carson City Water Company had entered into a 20-year contract with the Marlette Lake Company for 3,000,000 gallons of water per day, which provided that the State could purchase a maximum of 1,000,000 gallons per day and the Carson City Water Company could purchase 2,000,000 gallons daily. The water would be conveyed by the State's pipeline from The Tanks. The Virginia City Water Company like- wise had a contract to purchase water from the Marlette Lake Company not to exceed 300,000 gallons per day. In his letter to Governor Sawyer, Mr. Kruse went on to say that Mr. Walter Reid, a licensed engineer for Marlette Lake Company, stated that under normal op- eration conditions, the system had a capacity of 7,000,000 gallons per day, and that with certain im- provements the production could be 10,000,000 gallons daily during highest demand. In a letter to Ed Kruse from the Southwest Gas Corporation, which had purchased the Carson Water Company in 1960, it was stated that the Carson Water Company had been approached by the Marlette Lake Company with an offer to sell its properties. The letter stated that since Marlette Lake is the principal water source for the State building complex at Carson City, and is also a source of supplementary water for the Carson Water Company, it would seem prudent that either the Carson Water Company or the State of Nevada should purchase this very vital asset. Mr. Kruse had previously asked the Southwest Gas Corporation for an expression of interest in possibly purchasing the Marlette Lake Company assets from the State of Ne- vada, in the event the State should purchase the proper- ties and later decide to sell. In answering, Mr. Laub of the Southwest Gas Corporation stated the company def- initely would be interested in such an arrangement, with the qualification that should the State, at some time later, decide to sell, the price which the South- west Gas Corporation might offer must necessarily be based upon the asset value of the water rights. Laub further stated that his company would not necessarily be bound either contractually or morally to offer a price equal to the price that might have been paid by the State, should investigation disclose such price to have been excessive. 46 THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK FrcurE 26.-Signing of the agreement between the State of Nevada and Marlette Lake Company for the purchase of the Sierra water system June 12, 1963. Standing from left to right are Robert L. McDonald and Donald L. Carano, representing the Marlette Lake Company. Seated (left to right) are Wil- liam L. Paul, Deputy Attorney General, Hugh A. Shamberger, ex-officio State Land Register, and the late D. W. Priest, Deputy Attorney General. Photograph by John Nulty. After further negotiations, primarily between Mr. Kruse, representing the State, and the Marlette Lake Company, the company agreed to accept a price of $1,650,000. The Nevada State Legislature was then in session. After fully studying the assets of the Marlette Lake Company and the necessity of preserving the watershed and the water rights and facilities for the State, the Legislature approved an act authorizing the issuance of $1,650,000 of the State's negotiable coupon general obligation bonds and their delivery to the Marlette Lake Company, a Nevada corporation. The act au- thorized the State Land Register to execute a contract of purchase for such properties with the Marlette Lake Company; the bonds were to bear 3 percent interest, and were to be redeemed in 20 years. The same act created a State Bond Commission, composed of the Governor, Secretary of State, and State Treasurer. As ex-officio State Land Register, by virtue of being Director of the Department of Conservation and Nat- ural Resources, the author executed the agreement with the Marlette Lake Company on June 12, 1963 (fig. 26). The property consisted, in addition to all water rights held by the company, of some 5,378 acres, of land, in- cluding 80 acres at Five Mile Reservoir and 3.1 acres at Lakeview saddle upon which the caretaker's old house, built by the Virginia City and Gold Hill Water Company about 1873, is situated. In addition, there were included all road easements, flume and pipe ease- ments, and the easement from Five Mile Reservoir to a point 100 feet east of the reservoir, where a water meter has been installed. The Marlette Lake Company re- tained about 300 acres of land located immediately southerly from the Lakeview house (fig. 18). In order to test the legality of the agreement to pur- chase, the State Bond Commission, by resolution dated June 12, 1963, refused to issue and deliver the State's general obligation bonds on the grounds that it had doubts as to whether the purchase of Marlette Lake Company properties came within the authority con- tained in the second paragraph of Section 3 of Article 9 of the Constitution of the State of Nevada. They fur- ther stated in the resolution that it would create a public debt in excess of the debt limitation provided by the same Section 3, Article 9 of the Constitution. Thereupon the Marlette Lake Company sought a writ of mandamus to compel the State Bond Commis- sion to issue said bonds. The Supreme Court of Nevada held that the agreement for the purchase of the proper- ties was valid." Following this, the Marlette Lake Com- pany executed a deed conveying the assets of the com- pany to the State of Nevada, excepting the 300 acres of land heretofore mentioned, south of the old house at Lakeview. CONCLUSION Following acquisition of the Sierra water system by the State, considerable work was done by the Division of Buildings and Grounds in improving the water-col- lecting facilities. In 1966 there was not enough water in the Hobart Creek watershed to supply the water needs of Carson City. To augment the supply, a pump- ing station was installed on the east shore of Marlette Lake, and water was pumped over the divide to Hobart Creek. Again in 1967 the pump was utilized to convey water from Marlette Lake to meet the water demands. The old wooden flume from the east portal of the tun- nel was replaced with a steel pipeline. Although the tunnel had caved in in 1957, about 400 gallons per min- ute of water continues to flow from a spring area within the tunnel. This water, together with the water from some of the side canyons, is conveyed by the pipeline to Hobart Creek. In 1968 The Tanks were torn down, pre- sumably because they had become a fire hazard. (See fig. 3.) In 1967 the State Legislature authorized the Legisla- tive Commission (Senate Concurrent Resolution No. 21) to make a study of the Marlette Lake water system, its present and future requirements, and report the results of such study, together with specific recommendations, to the 1969 Legislature. The Legislative Commission ap- pointed a subcommittee to make the study. This study, Bulletin No. 79, was prepared under the general super- CONCLUSION 47 vision of Russell W. McDonald, Director of the Legis- lative Counsel Bureau, and was submitted to the 1969 Legislature in February 1969. This report is an ex- cellent presentation of the available facilities of the Sierra water system, and contains some of the early history of this system, together with numerous pictures, along with recommendations to the Legislature. The 1969 Legislature authorized the Legislative Commission to continue its study, and to advise the next session of the Legislature (1971) with regard to the administra- tion or disposition of the several elements of the Marlette Lake water system. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 28. 24. 25. 26. 27. 28. 29. 30. 31. 82. . Galloway, op. cit., p. 99. 34. 85. THE STORY OF THE WATER SUPPLY FOR THE COMSTOCK 49 NOTES AND REFERENCES . Lincoln, Francis Church. 1923. Mining Districts in Nevada and Mineral Resources of Nevada, p. 222. . Myrick, David F. 1962. Railroads of Nevada and Eastern California, p. 229. . Thompson and West. Howell-North Press, History of Nevada, pp. 508, 510 (1881). . Galloway, John Debo. 1947. Harly Engineering Works Con- tributing to the Comstock, p. 57. . Lincoln, op. cit., p. 226. . The Nevada Bureau of Mines lists the total production of the Comstock up to 1957 as being $393,963,725, with the production from 1920 to 1957 as being $28 million. Using Lincoln's 1921 production figure of $558,758 there is a difference of $19,794,448 between the two estimates, Lincoln's being the larger. . The census report of 1875 gives a population of 17,528 for Storey County. The year of peak production was 1877 and the population could well be doubled. DeQuille stated that according to the directory of 1875, the population of Virginia City was over 20,000, and that of Gold Hill about 10,000. These two towns made up the bulk of the population for Storey County then as they do now. . Department of Economic Development. 1967. Nevada Com- munity Profile, p. 129. . Thompson and West., op. cit., p. 502. 10. 11. Nevada Bureau of Mines, personal communication. Bancroft, Hubert Howe. 1890. History of Nevada, Colorado and Wyoming, p. 22; DeQuille, Dan. 1876. The Big Bo- nanza, p. 33; and Shinn, Charles Howard, 1896. The Story of the Mine, p. 226. DeQuille, Dan, op. cit. Thompson and West, op. cit., p. 600. Lord, Eliot. 1883. Comstock Mining and Miners, p. 259. Ibid., p. 259. Ibid., p. 260. In this description the writer is drawing to some extent on the account given by Lord. See Buck's letter following page 4. DeQuille, Dan. 1889. A History of the Comstock Silver Lode and Mines, p. 69. Galloway, op. cit., p. 57. DeQuille, The Big Bonanza, pp. 233-237. Lord, op. cit., p. 322. Reid, Walter G., is a professional engineer now residing at Virginia City. Davis, Sam P. 1918. The History of Nevada, p. 407. DeQuille, op. cit., p. 235. Galloway, op. cit., p. 70. Lord stated that the pipeline was 600 feet shorter. It would appear that the Galloway figure is most likely correct. Ibid., p. 71. The dam height was raised again in 1957, increasing the storage capacity to 35 million gallons, or about 800 acre-feet. DeQuille, op. cit., p. 237. Thompson and West, op. cit., p. 601. Lord, op. cit., p. 382. Galloway, op. cit., p. 78. Ibid., p. T1. Lord, op. cit., p. 332. Myrick, op. cit., p. 428. Scott, E. B. 1957. The Saga of Lake Tahoe. Sierra-Tahoe Publishing Co., p. 308. 36. 37. 88. 39. 40. 41. 42. . Thompson and West, op. cit., p. 506; and Smith, op. cit., 44. 45. 46. 47. 48. 49. 50. 51. 52. 58. . Smith, Grant H., op. cit., pp. 118-115. 55. 56. 57. 58. 59. 61. § a £ 71. 72. 78. Thompson and West, op. cit., pp. 505-511; Lord, op. cit., pp. 223-243, 333. Bancroft, op. cit., pp. 141-149. Stewart, R. E., and Stewart, M. F. 1962. Adoiph Sutro, a Bibliography. Davis, op. cit., pp. 399-405. Smith, Grant H. 1943. The History of the Comstock Lode, 1850-1920, p. 46. Davis, op. cit., p. 400. Smith, op. cit., p. 46. Davis, op. cit., p. 400. Stewart and Stewart, op. cit., p. 36. Ibid., p. 37. p. 109. According to Smith, the original plan was to extend tunnel westward under Mount Davidson far beyond the Comstock Lode. Lord, Eliot, op. cit., p. 234. DeQuille, Dan. 1889. A History of the Comstock Silver Lode and Mines, p. 69. Stewart and Stewart, op. cit., p. 108. Thompson and West, op. cit., p. 509. Ibid., p. 509. Ibid., p. 510. Stewart and Stewart, op. cit., p. 109. Lord, op. cit., p. 842. Thompson and West, op. cit., p. 504-505. Lord, op. cit., p. 342. Stewart and Stewart, op. cit., p. 112. Ibid, p. 168. Smith, op. cit., p. 279. Ibid, p. 256. Ibid., p. 256. . Lord, op. cit., p. 396. Ibid., p. 393. . Smith, op. cit., p. 269. . Patterson, Edna B., Ulph, Louise A., and Goodwin, Victor. 1969. Nevada's Northeast Frontier, pp. 662c-6624. . Smith, op. cit., p. 278. . Ibid., p. 280. . DeQuille, op. cit., p. 88. . Ibid., p. 87. 68. 69. TO. Ibid., p. 88. Davis, op. cit., p. 375. As related by Mrs. Jack Greenbalgh, of Virginia City, daughter of Tom Higgins, who told the author several in- teresting stories about Virginia City and the Sutro Tunnel. Mr. Harold Berger, of Carson City, son of Joe Berger, told the writer that he was born at The Tanks and his brothers, Frank, George, and Clarence and his sister Emma were born at the Lakeview house. Franktown Creek Irrigation Company, Inc., v. Marlette Lake Company, 77 Nev. 348, 374 P 24 1069 (1961). Marlette Lake Company, a Nevada Corporation, petitioner, v. Grant Sawyer, Governor of the State of Nevada, John Koontz, Secretary of the State of Nevada, and Michael Mirabelli, Treasurer of the State of Nevada, members of and constituting the State Bond Commission of the State of Nevada, respondents, 79 Nev. 334, 383 P. 2d 369 (1963). INDEX Alta Lake, 8 Alta Shaft, 33, 39 Anderson, Aleck, 1 Armer's Cigar Store, 39 Austin, Nevada, 2 Belcher-Crown Point, 39 Berger, Joe, 29, 42 Biltz, Norman, 44 Bishop, John, 1 "Bonanza" (the television show), 1 Boyle, E. D., 22 Bowers Mansion, 44 Bowers, Sandy, 2 Breed & Crosby, 22 Brown, Thomas, 26 Buck, S. M., 4 Bullion Ravine, 21 Burleigh drills, 33 California and Consolidated Virginia Co., 37, 39 California Electric Light Company, 39 California Mine, 39 Camp, ..., 2 Carson City, 18, 39, 46 Carson River, 32, 33 Carson City Water Company, 48, 45 Carson and Tahoe Lumber and Fluming Co., 23 Cartwright family (Bonanza), 1 C & C Shaft, 36, 37, 38, 39 Cedar Hill, 23 Cedar Hill Tunnel and Mining Co., 82 Central Mine, 32 Central Pacific Railroad, 18, 31 Chartz, Alfred, 32 Chinatown, 2 Chollar Shaft, 30, 37, 38 Cherokee Hydraulic Mining Co., 18 Clear Creek, 23 Clemens, Samuel L. (Mark Twain), 1 Cole Company, 3 Cole Tunnel, 3 Cole Silver Mining Company, 4 Combination Shaft, 39, 40, 41 Comstock, Henry Thomas Paige, 2 Comstock Lode, 32, 33 Comstock Mill, 37 Comstock Tunnel & Drainage, 37 Connell, John, 2 Consolidated Mill, 22 Consolidated Virginia, 32, 37, 39 Cornish pump, 38, 40, 41 Corral Canyon, 33 Cravens, Alfred, 26 Crown Point-Belcher, 8, 39 Crown Point Mine, 39 Crystal Bay, 31 Curtis-Wright Corporation, 43, 45 Dall, ..., 8 Dall Creek, 8 Daney Canyon, 32 Dayton, Town of, 2, 32, 33, 36 Dean, Walter S., 8 Divide, The, 30, 42 Dondero, F. N., 82 Division of Building and Grounds, 44, 46 Eagle Valley, 2 Elevations (By Reid), 17 Fair, James G., 1, 8 Feather River, 18 Finey (Old Virginia), 2 Five Mile Reservoir, 16, 17, 23, 29, 36, 42, 48, 44, 46 Field Circuit Justice, 4 Flood, James C., 1, 4, 8 Forman Shaft, 38, 39 Franktown, Town of, 44 Franktown Creek, 8, 44, 45 Franktown Irrigation Company, 44, 45 Gold Hill, 1, 16, 19, 22, 23, 28, 29, 42, 43 Gold Canyon, 1, 2, 32 Gold Hill Water Co., 3 Gold Hill and Virginia Turinel and Mining Co., 32 Goodwin Lake, 8 Greenhalgh, Mrs. Jack, 36 Greenhalgh, Jack, 37 Grosch Brothers, 2 Grosch Lode, 2 Hale & Norcross, 8, 32, 39 Hayward, Alvinza, 38 Heidenreich, Henry E., Roy F., and Edwin, 44 Hickman, James H., 2 Higgins, Tom, 29, 36, 42 Hobart, W. S., 8, 30, 38, 42 Hobart Creek, 8, 16, 22, 23, 27, 28, 29, 31, 42, 48. 45, 46 Hydraulic Pump, The, 45-46 Incline Creek, 28 Incline Lake, 44 Incline Village, 1 Incline's Great Tramway, 30 International Hotel, 2 Jessup, John, 2 Johntown, Settlement of, 2 Johnson, George C. & Company, 18 52 INDEX Knell, H. J., 45 Kruse, Edward, 43, 45 Lake Bigler (Tahoe), 23 Lakeview, Lakeview Saddle, Lakeview Hill, Lakeview House, 16, 17, 18, 19, 21, 23, 27, 29, 39, 42, 46 Lake Marlette, 26 Lake Tahoe, 1, 4, 23, 28, 31 Latrobe Tunnel and Mining Company, 32 Laub, William, 45 Legislative Commission, 46, 47 Leonard, Hobart, 4, 42, 43 Leonard, James, 29, 42, 44 Little Valley, 4, 8, 44 Long Valley, 43 Lyon County, 1 McCrindle and Company, 18 McDonald, Russell W., 47 McLaughlin, . . . , 2 McGovern, Harry E. (Red), 29, 31, 39, 42 Macey ledge, 4 Mackay, John W., 1, 8 Marlette, S. H., 23, 30 Marlette Lake, 8, 17, 23, 27, 28, 31, 42, 48, 46 Marlette Lake Company, 48, 45, 46 Marlette Lake Flume, 28 Mark Twain (Samuel L. Clemens), 1 Mexican Mine, 39 Mills, D. O., 1 Mint Tunnel, 32 Mill Creek, 28, 30 Mount Davidson, 1, 39 National Broadcasting Company, 1 Natilonal Tubing Company, 22 Nevada Mill, 38, 39 Nevada State Legislature, 46 Nevada Tunnel, 3, 4 New Yellow Jacket Shaft, 39 Newman, John L., 2 North (Third) Creek, 28, 44, 45 North End Mines, 39 North Flume, 31, 44 O'Brien, W. S., 1, 4, 8 'Old Virginny', 2 Ophir Claim, 2 Ophir Creek, 44, 45 Ophir Mine, 32, 39 Ophir Ravine, 3 Ormsby County, 31 Oroville, California, 18 Overton, Captain John Bear, 20, 23, 28, 29, 30, 31, 37, 38, 42 Pelton Wheel, 37 Penrod, ..., 2 Pioche, Nevada, 22 Plateau, Joe, 2 Ponderosa Ranch, 1 Price's Lake, 44, 45 Price, W. E., 44 Pyen, 40 Red House, 4, 8, 42, 45 Reid, Walter G., P. E., 16, 17, 45 Reilly, ..., 2 Reno, Nevada, 18 Richards, . . . , 2 Risdon Iron & Locomotive Works, 18, 20 Root blowers, 32 Sand Harbor, 31 Santa Rita Tunnel, 3 San Francisco, California, 8, 18, 32, 34, 36, 37, 39 Savage Shaft, 33 Savage Mining Company, 36 Sawyer, Circuit Judge, 4 Sawyer, Governor Grant, 45 Schussler, Hermann, 4, 8, 18, 21, 22, 23, 29, 33 Sharron, William, 1, 8, 34 Shaw, Jac, 44 Sides, ..., 2 Sides Lode, 32 Sierra Nevada Wood and Lumber Co., 29, 30, 42 Sierra Mountain Water, arrival of, 21 Sierra Nevada Mine, 39 Silver City, 1, 22, 28, 29, 82, 42 Simpson, John, 26 Six Mile Canyon, 38 Skae, John, 8 Southwest Gas Company, 45 Spring Valley Water Works, 8, 18 Spooner Lake, 8 Spooner Summit, 31 State Bond Commission, 46 State Land Register, 46 Storey County, 48 Summit Lake, 8 Sutro, Adolph, 32, 34, 36 Sutro Mill, 82 Sutro Townsite, 34, 36 Sutro Tunnel, 8, 22, 31, 32, 37, 39, 40, 41 Sutro Tunnel Act, 33 Sutro Tunnel Company, 33, 36, 37 Stewart, Senator, 33 The Line, 33 'The Tanks', 42, 45, 46 Third (North Creek), 28, 31, 44 Truckee River, 31, 39, 43 Tunnel Creek, 28 Tuscarora Water Company, 22 U.S. Geological Survey, 16 Union Mine, 39 Union Shaft, 83 'V' Flume, 31 Vigneau,.. . . , 2 Virginia City, 1, 3, 4, 8, 16, 18, 19, 21, 22, 23, 27, 28, 29, 31, 32, 36, 39, 42, 44 Virginia City Cemetery, 1 Virginia City Electric Company, 30, 38 Virginia Gas Company, 38 Virginia City Mines, 34 Virginia City Water Company, 4, 42, 48, 44, 45 INDEX Virginia and Gold Hill Water Co., 3, 4, 8, 20, 23, 28, 29, 7 31, 36, 37, 39, 40, 41, 42, 44, 46 (The) Virginia and Gold Hill Water Company, 42 Virginia Consolidated Mill, 22 Virginia and Truckee Railroad, 18, 31 Virginia mine, 39 Virginia Water Company, 3 Vucovich Brothers Magnolia Saloon, 39 Walker River, 1 Washoe Depression, 19 583 Washoe Valley, 4, 21, 22, 23, 27, 28, 44 Webber Canyon, 33 West Tunnel, 42 White and Murphy Lode, 32 Winchester, H. E., 4 Union Mine, 39, 40 Yellow Jacket, 2, 38, 40 Yerinton, H. H.. 1 U.S. GOVERNMENT PRINTING OFFICE: 1971 O-428-017 nremseues roma la he 2 9435