’W !it • ? • * PROCEEDING© OF THE CALIFORNIA ACADEMY OF SCIENCES Fourth Series Vol. VI, Nos. 1, 2 and 3, pp. 1-52, pi. 1. May 6, 1916 I Eocene of the Lower Cowlitz River Valley, Washington II • r fol< ' I, ■ ■ ' • \, :4” J • Iffy/1 • <* ■: I »’• -X jfel X-X< .«•'•».$ The Post-Eocene Formations of Western Washington hi The Oligocene of Kitsap County, Washington BY Charles E. Weaver Assistant Professor of Geology, University of Washington, Seattle If TA"' ,/j 'I > "ft • '‘i , i;.., .. ■ WiMMl UMI|1 i SAN FRANCISCO Published by the Academy 1916 I 737 W43 cop.2 ? i i I j pip . ' HCOMMITTEE ON PUBLICATION George C. Edwards, Chairman C. E. Grunsky Barton Warren Evermann, Editor THE HICKS JUDD PRESS SAN FRANCISCOGif) PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES Fourth Series Vol. VI, No. 1, pp. 1-17, pi. 1. May 6, 1916 I EOCENE OF LOWER COWLITZ RIVER VALLEY, WASHINGTON BY Charles E. Weaver Assistant Professor of Geology, University of Washington, Seattle INTRODUCTION The purpose of this paper is to place upon record the results of geologic and faunal studies made by the writer during the past three years in portions of the lower Cowlitz River Valley. The area under investigation is of special interest because of the large number of exposures of Eocene strata and the exceptionally well preserved faunas contained within them. Surface outcrops of Tertiary formations in western Washington are largely obscured because of the heavy overburden of Pleistocene deposits. In King and Pierce counties much detailed work has been done so that the lithology and structure of the Eocene rocks is fairly well known.1 The strata in this region are, however, almost entirely of estuarine origin, rendering it impossible to make satisfactory correlations with the Eocene of other parts of the Pacific Coast. Isolated outliers of Eocene rocks occur in many localities such as Crescent Bay 1Willis, Bailey, and Smith, Geo. O., Tacoma Folio, U. S. Geol. Surv. 1899. May 6, 19162 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. along the Strait of Juan de Fuca, the low hills about Tenino and Centralia in Chehalis County and the exposures on Coal Creek north of Columbia River in Cowlitz County. At these localities only fragmentary sections of the Eocene column of Washington can be studied. The region under discussion in this paper contains the most complete fossiliferous marine section occurring within the western portion of the state. REVIEW OF LITERATURE One of the earliest important scientific references to the geologic conditions in this region is to be found in the report by Dr. Ralph Arnold2 on “The Tertiary and Quaternary Pec-tens of California.” He described Pecten landesi from this area. The following quotation is well worth noting: “F. landesi is found quite abundantly in a dark greenish sandstone bed that outcrops about 100 yards west of the junction of Stillwater and Olequah creeks (U. S. Nat. Mus. locality 4019) one-fourth mile southwest of Little Falls, Lewis County, Wash. It is also found in a similar matrix in the bed of Olequah Creek (U. S. Nat. Mus. locality 4024), one mile north of the first locality. It is associated in this formation with a characteristic Eocene fauna, among which are the following species: Veneri-cardia planicosta Lamarck, Thracia dilleri Dali, Crassatellites sp., Meretrix sp., Ostrea sp., Pteria (cf.) limula Conrad, Car-dium 2 sp., Barbatia sp., Glycimeris sp., Corbula sp., Callista sp., Turritella (cf.) uvasana Conrad, Fusus 4 sp., Ocinebra sp., Ranella sp., Calyptrophorus sp., Lunatia sp., Turbinella (?) sp., Murex 2 sp., Conus sp., Cassis sp., Tritonium sp., Dentalium (cf.) cooperi Gabb, and Nautilus sp. This horizon is probably upper Eocene, possibly above the Tejon.” Dr. Arnold’s suggestion that this horizon is very high in the Eocene seems to be well in accord with more recent studies. The Geology and Paleontology of this area is discussed in a paper by the writer3 published in 1912. A large fauna was noted as occurring along the banks of Cowlitz River about one 2Arnold, Ralph, The Tertiary and Quaternary Pectens of California. Paper 47, U. S. Geol. Surv., p. 52, 1906. ’Weaver, C. E., “A Preliminary Report on the Tertiary Palaeontology Washington,” Bull. 15, Wash. Geol. Surv., pp. 12-15, 1912. Professional of WesternVol. VI] WEAVER— EOCENE OF LOWER COWLITZ VALLEY 3 and one-half miles east of the town of Vader in Lewis County. Many new species of mollusks were described and the fauna as a whole was referred to the Cowlitz formation which was regarded as of Eocene age and possibly older than the Tejon. A suggestion was, however, made that future studies might show that it was identical with the Tejon. A further discussion of this region is to be found in a report by Arnold and Hannibal4 on “The Marine Tertiary Stratigraphy of the North Pacific Coast of America.” In this paper the Tejon is divided into three formations: the Chehalis, Olequah and Arago formations. They are referred to as the Tejon Series. The Chehalis and Olequah formations are present in the region involved in this report. The Arago is absent. On the basis of fossil floras colder climatic conditions obtained during the deposition of the Chehalis formation than during that of the Olequah. During the last year an important paper appeared by Dr. Roy E. Dickerson5 entitled the “Fauna of the Type Tejon: Its Relation to the Cowlitz Phase of the Tejon Group of Washington.” Collections were made and studied from certain localities along the Cowlitz River and a number of new species were described. A total of 95 species are listed from Washington, and 55 of these are found within the Tejon of California. The paper gives the results of studies at the type Tejon locality in southern California and makes correlations with the Cowlitz phase of the Tejon in Washington. He states “The Cowlitz phase of the Tejon of Washington appears to represent the same faunal facies as the fauna of the type Tejon, i. e., the Rimella simplex zone is present in both localities.” GEOGRAPHY OF AREA UNDER INVESTIGATION The region involved in this study is situated in southern Lewis County and extends from the town of Winlock southerly for a distance of fifteen miles to the town of Castle Rock. From east to west the area averages five miles in width. Just east 4Arnold, Ralph, and Hannibal, Harold, The Marine Tertiary Stratigraphy of the North Pacific Coast of America, Proc. Am. Phil. Soc., vol. 52, pp. 566-571, 1913. 5Dickerson, R. E., “Fauna of the Type Tejon: Its Relation to the Cowlitz Phase of the Tejon Group of Washington.” Cal. Acad. Sci. Proc., 4th series, vol. 5, pp. 35-51, 1915.4 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. of the town of Vader (formerly known as Little Falls and So-penah) the Cowlitz River swings from its east-west course and assumes a due north-south direction. One mile south of Vader, Stillwater Creek enters Cowlitz River and about one-fourth mile south of the town, Olequah Creek joins Stillwater Creek. From this point Olequah Creek extends almost due north to Winlock. The Northern Pacific Railway between Portland and Seattle follows the valley of this creek. The drainage of the entire area is southerly to the Columbia and the hills on either side rise gradually into a rolling timbered country. Eocene strata away from the banks of the creeks are not exposed but are covered with gravels and sands formerly deposited by Cowlitz River. STRATIGRAPHY In the examination of this region a transit survey was made of Stillwater and Olequah creeks and the position of all fossil localities as well as observations taken upon strikes and dips definitely located. These data have been plotted upon the map accompanying this report. Between the towns of Castle Rock and Olequah only four exposures of Eocene strata are known to occur. They consist of dark gray, sandy shales with intercallated basaltic flows. Two miles north of Castle Rock and 2,000 feet south of the Northern Pacific Railway bridge over Toutle River, there is an exposure in the railway cut composed of bedded tuffaceous materials together with sedimentary deposits of worked over basalt. These beds have a strike of N. 75° E. and a dip of 5° N. W. They are overlaid with Pleistocene deposits composed of sand and gravel intermixed with angular fragments of basalt, which appear to have been derived by rapid erosion from nearby bluffs of Eocene basalt. From this point northerly for a distance of two miles the only exposures along the railway consist of Pleistocene gravels and sands. One and two-thirds miles north of the Toutle River bridge Eocene rock outcrops occur for a distance of 450 feet. The bluffs at this point are about 60 feet high and con- Vol. VI] WEAVER—EOCENE OF LOWER COWLITZ VALLEY 5 sist of thinly bedded, fine-grained, dark brown shale containing a few narrow bands of sandstone. The total thickness of the sediments at this point is about 75 feet. They are overlaid with 35 feet of black basalt showing well defined columnar jointing. Both the sedimentaries and lavas have a strike of N. 80° E. and a dip of 10° to the N. W. About one-half mile south of the railway bridge across Cowlitz River there is a third exposure of Eocene basalt but no sedimentary rocks. The lower portion of the bluff is made up of agglomeratic materials consisting of a heterogeneous mass of angular fragments of badly weathered, dense and vesicular basalt having a thickness of 20 feet. Above this is a flow of fine grained, dense, black basalt exhibiting a tendency to columnar structure. The approximate strike of these flows is nearly east and west with a low dip to the north. The eroded surface of this outcrop is overlaid with Pleistocene sands and gravels. One-half mile north of the previously mentioned outcrop, and along the south bank of Cowlitz River at the railway bridge, basalts and sedimentary rocks again appear. At the south end of the bridge and along the river there is a quarry composed of basalt exhibiting pronounced columnar structure. Lying conformably below the basalts are dark shales and brown sandstones, which’ in places contain narrow carbonaceous bands. They are about 60 feet in thickness with a strike of N. 35° W. and a dip of 10° to the N. E. From this point northward to the town of Olequah no recognizable exposures of the Eocene occur. At one of the above mentioned localities a single specimen of Turritella uvasana Conrad was collected, but aside from this, the only fossils occurring are a few plant fragments and wood. From observations taken upon strike and dip there appears to be a continuous low dipping series of sedimentary beds with intercallated basaltic flows extending from Castle Rock to Olequah. However, it is possible that there may be folding and faulting in the intervening covered areas. If the strata are continuously dipping northward they possess a thickness of at least 6000 feet. From Olequah northward to Winlock, where the strata are better exposed, a stratigraphic sec- t6 CALIFORNIA ACADEMY OF SCIENCES [Paoc. 4th Ser. tion can be made. The sediments in the area between Castle Rock and Olequah are stratigraphically below those outcropping between Olequah and Winlock. Section between Olequah and Winlock:—Strata of Eocene age outcrop in the banks of Olequah and Stillwater creeks and also along the railway track at many places between Olequah and Winlock. They consist predominately of massive, sandy, clay shales together with grayish brown sandstones containing: carbonaceous seams. These materials are of marine, brack-ish and fresh water origin. With the exception of the basal portion of this section, basaltic flows are absent. The basal part involves certain sandstones and basalts outcropping at the town of Olequah. The upper portion of the section is two miles south of the town of Winlock. The actual contact of the upper limit of the Tejon and the overlying Oligocene has not been definitely determined. Four hundred feet south of the last Oligocene outcrop in the banks of Olequah Creek are Eocene shales containing a marine Tejon fauna. It is impossible to say whether the two formations are conformable or not. The strata have approximately the same strike, but the dip of the Oligocene is only 2° to the northeast, while that of the Tejon is 27° in the same direction. It is possible that the two formations are conformable but that in the interval of 400 feet between them the dip flattens out. The lower portion of this section as exposed along Stillwater Creek to the southwest of Vader and as far south as Olequah is of marine origin. Stratigraphically above, these strata grade into those of brackish water origin and finally into those containing a freshwater fauna. Still higher up in the section they pass back to a brackish water condition and finally to marine. The entire upper portion of the section is a marine deposit. The total thickness of the Eocene section, as measured from Olequah to Winlock, is approximately 4970 feet. The following stratigraphic section shows approximately the variations in the lithologic character of the sediments from the base to the top. including a part of the overlying Oligocene.Vol. VI] WEAVER—EOCENE OF LOWER COWLITZ VALLEY 7 Top of Section peet Banded sandstone and shale as exposed at the town of Winlock and in the banks of Olequah Creek to the west and northwest of town. The fauna occurring at Locality No. 229 is characteristic of this zone............................................ 500 Massive clay shale grading in places into sandy shale as exposed along the banks of Olequah Creek south of Winlock and also in the bank of Cowlitz River in Section 5, Township 11 North, Range 2 West, at fossil Locality No. 239 (locally known as the Graeco Ranch). This is the base of the Oligocene in this region ...................................................... 600 Top of Eocene section. Chiefly sandy shale grading into massive clay shale of a dark brownish gray color. Exposures representing this phase are not very abundant but contain occasional specimens of Venericardia planicosta Lamarck and Tur-ritella uvasana Conrad .............................................. 960 Shaly sandstone .................................................... 100 Slightly banded sandy shale......................................... 130 Slightly carbonaceous sandy shale.................................... 50 Sandy shale ..;...................................................... 430 Laminated sandstone and sandy shale................................. 150 Shale, slightly sandy. The upper part of this zone contains an abundant marine Tejon fauna..................................... 340 Massive clay shale containing the fauna at Localities Nos. 1, la, 232 and 233, in the north bank of Cowlitz River, Section 25, Township 11 North, Range 2 West.............................. 50 Sandy clay shale. This is the base of the upper marine division of the section ................................................ 70 Brackish water zone. Yellowish brown sandstone with interbedded lignitic layers. These sandstones often grade into carbonaceous sandy shales................................................. 520 Freshwater zone. Light gray massive clay shale, containing numerous freshwater Eocene invertebrates. Fossil Localities Nos. 295 and 303 occur in these shales........................... 130 Lower brackish water zone. Sandy shales and shaly sandstones often grading into brownish yellow coarse grained sandstones. All are more or less carbonaceous. Fossil Localities Nos. 231, 234 and 300 occur within this zone..................... 550 Lower marine zone. Sandy clay shales grading into shaly sandstones. Fossil Localities Nos. 240, 240b, 299, 241, 238, 301, 236, 298, 294 and 294a occur within this zone. The basal portion of this belt contains a few very narrow layers of brackish water sediments. Below this belt no detailed measurements of the strata have been made. The underlying strata are those involved in the area between Castle Rock and Olequah. Just below the base of these marine beds, flows of basalt and deposits of basaltic tuff are intercallated with the sediments, which appear to be predominatingly of brackish water origin.. 390 Total thickness of measured strata between Olequah and Winlock ............................................................ 4,970 Possible thickness of unmeasured strata involved in area between Castle Rock and Olequah..................................... 6,000 Possible total thickness of Eocene as exposed in the lower Cowlitz Valley section ............................................. 10,970 « -w '*■ • s’ *.*•*'* f1 !* * * Mi. ' r. x j M *8 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. STRUCTURE The entire series of Oligocene and Eocene deposits involved in this region exists in the form of a northeasterly low dipping monocline. It is probably the southwestern limb of a broad syncline, the northeastern limb of which occurs in the region around Chehalis and Centralia. There are minor undulations in the northeasterly pitch of the strata between Olequah and Winlock. In the vicinity of Vader a low, shallow anticline has been developed whose axis trends N. 30° W. It crosses Olequah Creek one-half mile north of Vader. The strata on the north side of this minor fold dip to the northeast at an angle of 40° and on the southwest side at an angle of 15°. One thousand feet south of the axis of the minor anticline there is a shallow syncline having approximately the same trend as the anticline. At the point where the axis of the anticline crosses Olequah Creek the same marine strata are brought to the surface which occur to the southwest of Vader along Stillwater Creek above its junction with Olequah Creek. A glance at the map accompanying the report indicates several apparent discordances in strike and dip in the vicinity of Olequah. It might be inferred that the strata had been greatly disturbed and faulted. However, such is not the case. There are simply minor undulations in strike and dip along the prevailing direction of strike. The variations as shown upon the map were inserted for the purpose of emphasizing these irregularities. FAUNAL RELATIONS In constructing the stratigraphic section accompanying this paper an attempt was made to arrange the fossil localities in their stratigraphic sequence. The following localities range from the base near Olequah to the upper portion of the section near Winlock: Localities Nos. 299, 5, 236, 298, 294, 294a, 241, 238, 301, 231, 234, 300, 295, 1, la, 232, 233, 239, 292 and 229. Localities 299 to 301 contain a marine fauna. Localities 231 to 300 contain a brackish water fauna. Localities 295 and 303 contain a freshwater fauna. Localities Nos. 1 to 233PROC. CAL. ACAD. SCI., 4th Series, Vol. VI. [WEAVER] Plate 1 Sketch .lap showing structural conditions along Cowlitz River between Olequah and Winlock.Vol. VI] WEAVER—EOCENE OF LOWER COWLITZ VALLEY 9 contain a marine fauna. Localities Nos. 239 to 229 have a marine Oligocene fauna. A description of the locations of the several fossil localities is here inserted. Locality No. 299—From an embankment along the Northern Pacific Railroad, 2850 feet south of milepost 76 and three-fourths of a mile north of Olequah Station, in Section 32, Township 11 North, Range 3 West. Locality No. 5—From a fossil ledge at the junction of Olequah and Stillwater creeks, in Section 32, Township 11 North, Range 3 West. Locality No. 236—On Stillwater Creek, Lewis County, 2200 feet above its junction with Olequah Creek, in Section 30, Township 11 North, Range 2 West. Locality No. 298—About 100 feet west of Locality No. 236. Locality No. 29-4—In the bank of Stillwater Creek about one and one-third miles below its junction with Olequah Creek in Section 30, Township 11 North, Range 2 West. Locality No. 294a—An earlier collection made at same Locality as No. 294. Locality No. 241—In the bank of Stillwater Creek about one and two-fifths miles below its junction with Olequah Creek, in Section 30, Township 11 North, Range 2 West. Locality No. 238—On Olequah Creek three-fourths of a mile north of Vader Station in the east bank of the creek just north of a point where a small creek enters Olequah Creek from the east. In Section 29, Township 11 North, Range 2 West. Locality No. 301—From the banks of Olequah Creek one-half mile north of Vader and south of the four-foot falls in the creek. The strata vary from a shaly sandstone to a sandy shale. Locality No. 231—Fossil Locality No. 234 should also be considered with No. 231, as they are both from the same locality, but from two separate ledges only eight feet apart. From Olequah Creek about three-fourths of a mile north of Vader, just south of the big bend in the creek. A small band of fossils. In Section 28, Township 11 North, Range 2 West. Locality No. 234—A narrow band in Olequah Creek about three-fourths of a mile north of Vader, just south of big bend in creek. About eight feet stratigraphicallv above Locality No. 231. Locality No. 300—On Olequah Creek one-fourth mile above Vader Station, in east bank of creek just north of point where small creek enters from east. In Section 29, Township 11 North, Range 2 West. Locality No. 295—Located about one and one-half miles north of Vader, in the bend in Olequah Creek at the point where the creek lies close to the Northern Pacific Railway track at milepost No. 73. The fauna is entirely of freshwater origin and is in a belt of gray shale. Locality No. 1—Located about one and one-half miles east of Vader, on the west bank of Cowlitz River, in massive sandy shales of marine origin, situated in Section 27, Township 11 North, Range 2 West.10 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. Locality No. la—A zone at the base of the section as represented at Locality No. 1. Locality Nos. 232 and 233—second collection made at Locality No. 1 and kept separate from No. 1. Locality No. 239—Located in the N.E.% of Section 25, Township 11 North, Range 2 West, on the east side of Cowlitz River three-fourths of a mile above the ferry on Mr. Greece’s ranch. The fauna is Oligocene and is the equivalent of the faunas occurring south of Winlock in Olequah Creek at Localities Nos. 292 and 229. Locality No. 292—Oligocene, one mile south of Winlock in bank of Olequah Creek. Locality Nk>. 240—An Eocene locality south of Vader in the banks of Stillwater Creek at a dam near the lumber mill. The locality is just east of the Northern Pacific Railway bridge over the creek. The strata are sandy shales and sandstones dipping at low angles to the northeast. Immediately above these strata brackish water species appear.Faunal Lists Locality 299 5 236 298 294 294a 241 238 301 231 234 300 295 1 la 232 233 240 BRACHIOPODA Terebralulina washingtoniana Weaver X X X X X X X PELECYPODA Acila washingtonensis Weaver . X X Avicula pellucida Gabb Barbatia morsei Gabb X X X X X X X X X X X X X X X X X X X X X X X Cardium brewer ii Gabb X X X X Cardium cooperii Gabb 5? Cardium olequahensis Weaver X X X X Corbula hornii Gabb X X X X X X Corbula, new species Corbicula cowlitzensis Weaver X X Crassatellites grandis (Gabb) X X X X X X Crassatellites cowlitzensis Weaver X X X X X X Crassatellites dalli Weaver X X Crassatellites merriami Weaver X Crassatellites washingtoniana Weaver X X X X X X X X X Crassatellites compacta Gabb X X Cyrene brevidens White X X X Corbicula cowlitzensis Weaver Diplodonta polita (Gabb) X X X X X X X Glycimeris eocenica Weaver X Glycimeris sagittata (Gabb) X X X X X X 5? "x~ Glycimeris eocenica landesi Weaver X Leda gabbi Conrad X X X X X X X X X X X Leda vaderensis Dickerson Marcia quadrata (Gabb) X X X ’ x X X Macrocallista (?) andersoni Dickerson Macrocallista conradiana (Gabb) X X X X X "x X X X X X X X X Macrocallista vaderensis Dickerson Meretrix olequahensis Weaver Meretrix ovalis Gabb ♦ X X X X X X X X X Meretrix uvasana Conrad X X X X X x‘ X X Meretrix hornii Gabb X X x X X X X ”x‘ Meretrix longa Gabb X X X Meretrix, new species X X Modiolus ornatus (Gabb) X X x X x X X Ostraea fettkei Weaver X X X ’ X X X Vol. VI] WEAVER—EOCENE OF LOWER COWLITZ VALLEYFaunal Lists—(Cont.) Locality 299 5 236 298 294 294a 241 238 301 231 234 300 295 1 la 232 233 240 Ostraea idriaensis Gabb X X X X X XXXX x Ostraea olequahensis Weaver Pecten cowlitzensis Weaver Pecten landesi Arnold X X Placunanomia inornata Gabb X X X X X X X X X Psammobia hornii (Gabb) X X X X X X X Semele diaboli Dickerson Septifer dichotomus Gabb X X Solen parallelus Gabb X X X X X Solen lincolnensis Weaver X X Thracia dilleri Dali Tellina sutter ensis Dickerson X x’ Tellina longa Gabb X X X X X X X X X Tellina hornii Gabb X X X X X * x Tellina malhewsonii Gabb T eredo, sp X X X X Unio transpacifica Arn. & Hann X Venericardia planicosta hornii (Gabb) X X X X X X X X X X X X X X X X X X X X X X SCAPHOPODA Dentalium siramineum Gabb Cadulus pusillus (Gabb) GASTEROPODA Amauropsis alveata (Conrad) X X X X X X Amphissa eocenica Weaver X X X X X X X Amphissa packardi Weaver A neillaria bretY.i Weaver X X A mbloxus olequahensis Arn. & Hann X Bursa Washington iana X X X X X X Bursa cowlitzensis Weaver Braehysphingus clarki Weaver X X X X X x X X x Calyptraea excentgica (Gabb) X X X X X X X X X X X Crepidula pileum Gabb Crepidula new species x Cylichna costata Gabb X X X X X X X X X X X X Cnnrell.nrin. stnnt.oni. Dickerson Cei.nt.hn.ru s berrini Dickerson Conus hornii Gabb CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. Faunal Lists—(Cont.) Locality 299 5 236 298 294 294a 241 238 301 231 234 300 295 1 la 232 233 240 Conus remondii Gabb X X Conus weaveri Dickerson X X Conus cowlitzensis (Weaver) X X Drillia ornata Dickerson X X Exilia dickersoni Weaver X X X X • • • • Exilia perkinsiana (Cooper) X X X X .... Ficus mamillatus Gabb X X X Ficus, new species X X Fusus washingtoniana Weaver X X Fusus lewisensis Weaver . X X X X • • • • Fusus willisi Dickerson X X Fasciolaria buwaldana Dickerson X X Fasciolaria washingtoniana Weaver.. . X X Ficopsis remondii Gabb X X X X • • • • Ficopsis cowlitzensis Weaver X X X X X X X Galeodea washingtoniana Weaver . . . . . X X Galeodea tuberculata (Gabb) X X Ilemifusus sopenahensis Weaver X X X H emifusus lewisiana Wfcaver X X • • • • IIemifn su s snnshin vtfvninnn. Wpavpr • X X H emifusus teinriFn sis Weaver X X • • • • I.unn.ti.fi. rmnlitnen si s Dickerson X X X T.unntin. u nrifnrmi s GaLL X X .... I'CbMfl fjn ‘itinshiwolnMPwris AA^pnvpr X X Mitrn wfishiw vtmii nun Vl^p^vpt* • X X X X • • • • l\zfnrPY miniitwvi sis Weaver X X X X l\/I mitpy 'hnrhnvflj T^iplrpr^nn X X MrlnnifL 'hnrknrrti Dickerson X X X X • • • • X X .... ,VZfilnnin fettkei XUpovpf X X 'Mrln'Hin lenoM s'in'nn Wpavpr X X X X .... X X A7everitn. sprtn Gakb X X X X X X X • • • • X . . . . X X X X X X X X X X X X X X X X X X • • • • Vol. VI] WEAVER—EOCENE OF LOWER COWLITZ VALLEY Faunal Lists—(Cont.) Locality 299 5 236 298 294 294a 241 238 301 231 234 300 295 1 la 232 233 240 Neverita subglobosa Gabb X X X X X X X Nyctilochus washingloniana Weaver Niso polito Gabb Odostomia packi Dickerson X X X X X Olivella mathewsonii Gabb X • • • • Olivella, new species X • • • • Pachyhilus drakei Arn. & Hann X • • • • Pseudoliva inornata Dickerson X X X X X X X X X X X X X X X X X X X X Pseudoliva volutaeformis Gabb X X X X Rimella elongata Weaver X X X Rimella simplex Gabb Siphonalia bicarinata Dickerson Surcula ivashingtoniana Weaver X X X X X Surcula cowlilzensis Weaver X Sinum obliquum (Gabb) X X X Turris 'ivashingtoniana (Weaver) Turris pulcher Dickerson Turris monolifera Cooper — X X X X X X X Turrilella uvasana Conrad X X X X X X X X X Turritella, new species • • • • Turritella, new species Turritella, new species X X X X X X X Triforis washingtoniana Dickerson • • • • Urosalpinx hannibali Dickerson X • • • • Vipiparus Washingtonian a Arn. & Hann X • • • • CEPHALOPODA Aturia mathewsonii Gabb X X X X Aturia, new species X bi o n k to x: o bi c< bi n bi Co b3 w o 9 -u H w CZ5 w » < Vol. VI] WEAVER—EOCENE OF LOWER COWLITZ VALLEY 15 The above listed faunas are typically Tejon. The Cowlitz phase of the Tejon as represented at Locality No. 1 on the Cowlitz River one and one-half miles east of Vader was in a previous paper by the writer regarded as older than the Tejon, and more closely related to it than to the Martinez of California. Since the publication of that report more extensive collections have been made, as well as more detailed stratigraphic studies. The faunal evidence now points directly to its Tejon age. Dr. Dickerson6 believes it is to be correlated with the type Tejon of Grapevine Canyon in southern California. He considers it to represent the middle division of the Tejon or Rimella simplex zone. Arnold and Hannibal7 in their report on “The Marine Tertiary Stratigraphy of the North Pacific Coast of America'’ consider two divisions of the Tejon to be present in the Olequah Creek region. The lower division or Chehalis formation is described as occurring at “the bluffs along Cowlitz River below the mouth of Drew Creek, one and one-half miles east of Olequah.” It is*apparent that they must have meant Vader rather than Olequah, as Cowlitz River is less than one-half mile east of Olequah, and the only rock exposures in that region are deposits of Pleistocene gravels and sands. Their faunal locality, No. 113, is probably the same as Locality No. 1, la, 232 and 233 of this report and California Academy of Sciences Localities Nos. 182 and 183, as referred to in Dr. Dickerson’s report. Detailed stratigraphic measurements made with a transit show that the strata occurring at the above mentioned localities are stratigraphically higher than the strata exposed along Olequah Creek from a point two miles north of Vader southward to Olequah. The type locality of the Olequah formation as described by Arnold and Hannibal “extends from the Erwing ranch a little over two miles above Little Falls southward down Olequah Creek to Olequah, a distance of about five and one-half miles.” In this area, where both the Chehalis and Olequah formations are described as occurring by Arnold and Hannibal, stratigraphic evidence shows their lower division or Chehalis for- 6Dickerson, Dr. R. E., “Fauna of the Type Tejon: Its Relation to the Cowlitz Phase of the Tejon Group of Washington.” Cal. Acad. Sci. Proc., 4th series, vol. 5,16 CALIFORNIA ACADEMY OF SCIENCES [Peoc. 4th See. mation to rest upon their upper or Olequah formation. Their evidence for two divisions here seems to have been based in part upon the evidence of fossil floras. An examination of the faunas obtained at various intervals from the base of section at Olequah to near the top at Winlock shows very little difference in their composition. It is true that near the middle of the section brackish and fresh water beds appear, but the marine faunas below and above are very similar. A comparison of the faunas occurring in the Eocene strata of the Cowlitz River area with those which have been listed and described from the type Tejon in southern California leads the writer to the same conclusions as have been stated by Dr. Dickerson, namely, that the Tejon of the Cowlitz River area is the equivalent of the middle zone in California as represented in the Mount Diablo region. CONDITIONS OF DEPOSITION The Eocene of western Washington is widely distributed. It extends well up into the western portions of the Cascade Mountains and may even possibly connect beneath a thick covering of Miocene lavas with the Eocene deposits on the eastern slopes of the mountains. The Eocene deposits involved within the western slopes of the Cascades are almost entirely of brackish or fresh water origin. No marine strata are known to be interbedded. In the Puget Sound Basin, brackish water deposits predominate, but in southwestern Washington great thicknesses of marine deposits are interbedded. During the upper Eocene the larger part of southwestern Washington and a portion of the Puget Sound Basin appear to have been an embayment of the ocean. The present site of the western slopes of the Cascade Mountains seems to have been in part occupied by large estuaries. During Tejon time diastrophic movements were differentially acting upon the entire western portion of the state, causing fluctuations in the depth of water in the embayments and estuaries and a shifting of the shorelines. These oscillations are recorded in the interbedded character of the marine and brackish water sediments. The eastern shoreline of the southwestern Washington embayment appears to have existed at times along the present site of the NorthernVol. VI] WEAVER—EOCENE OF LOWER COWLITZ VALLEY 17 Pacific Railway line from Centralia to Portland. An interpretation of the stratigraphic section shows that this shore line was alternately shifting east and west as the sea floor was being differentially elevated and depressed. The effect of those diastrophic movements as recorded within the area involved in this paper may be seen in the passage from marine to brackish and fresh water and thence back again to marine. The marine faunas as listed above indicate tropical climatic conditions and an environment ranging from shallow water to moderately deep water. CONCLUSIONS Within the area studied between Winlock and Olequah there are about 4000 feet of shales and shaly sandstones of upper Eocene age. Beneath these, between Olequah and Castle Rock, there are possibly 6000 feet of unmeasured upper Eocene sandstones and shales, together with numerous intercallated layers of basaltic lavas. Overlying the Eocene in the vicinity of Winlock and at the Graeco ranch on Cowlitz River are marine deposits of Oligocene age. A section of the Eocene measured between Olequah and Winlock consists of a lower division of marine beds at least 400 feet in thickness. This is overlaid by 550 feet of brackish water strata and that in turn with 300 feet of freshwater beds. Above the freshwater beds are 520 feet of brackish water strata. Above these are marine beds having a thickness of 2410 feet. These strata are all fos-siliferous and appear to be most closely related to the middle Tejon as described in the Mount Diablo region of central California. The basement upon which the Tejon in this area rests, as in the case of most of western Washington, is unknown. The fauna of the upper portion of the Cowlitz section bears a close relation to the overlying Molopophorus lincolnensis zone of the lower Oligocene as represented to the north in the vicinity of Lincoln Creek, in Thurston County. PROCEEDINGS OF THE ♦ CALIFORNIA ACADEMY OF SCIENCES Fourth Series Vol. VI, No. 2, pp. 19-40. May 6, 1916 II THE POST-EOCENE FORMATIONS OF WESTERN WASHINGTON BY Charles E. Weaver Assistant Professor of Geology, University of Washington, Seattle INTRODUCTION Marine deposits of post-Tejon age form a considerable part of the formations exposed at the surface in western Washington. They have been folded and eroded, and. in some areas, are deeply buried beneath sand and gravel of glacial and flu-viatile origin. As a result, outcrops are usually found in the form of low cliffs along the banks of rivers and creeks or along the sea cliffs of the Sound or ocean. Certain portions of these OligocenS-Miocene formations yield fairly abundant marine invertebrate faunas. Upon a faunal basis five separate divisions of the post-Tejon portion of the Tertiary can he recognized. Marine deposits of Pliocene age with the exception of a very small area on the western side of the Olympic Peninsula are unknown within the state. The uppermost division or upper Miocene is separated from the lower four divisions by a well-marked unconformity. The pre-Pleistocene formations of the southwestern portion of the state are somewhat oh- May 6, 1916 20 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. scured by clays, sands and gravels of fluviatile origin. In many areas the Tertiary rocks themselves have been so deeply weathered that very little information can be obtained concerning their lithologic character and structure. All parts of western Washington are clothed with a dense growth of forest and underbrush, which conceals many exposures of Tertiary rocks which are not covered with Pleistocene sands and gravels. LITERATURE Numerous references to the occurrence of Tertiary strata may be found in papers dealing with the geology of western Washington. The majority of these papers involve investigations of economic products such as coal and contribute little to the purely scientific phases of Tertiary geology. Only the more important literature is here reviewed. James D. Dana referred to Tertiary strata in the report on the geology of the United States Exploring Expedition under Wilkes1 as occurring to the north of Columbia River and along the shores of Puget Sound and the Strait of Juan de Fuca. Collections were made from the south side of Columbia River at the town of Astoria. This fauna was identified by Conrad, who regarded it as Miocene. Marine Neocene deposits are mentioned by Dr. Bailey Willis as occurring near Seattle immediately north of the C? J northern limits of the Tacoma quadrangle.2 These deposits are not described. The first detailed description of the occurrence of Oligo-cene-Miocene strata within the state is to be found in a report by Dr. Ralph Arnold3 on a “Geological Reconnaissance of the Coast of the Olympic Peninsula, Washington.” Oligocene-Miocene deposits are described as occurring along the northern border of the Olympic Peninsula. Pliocene deposits are mentioned as being present on the west coast of the peninsula near the mouth of Queniult River. The Miocene deposits are composed of conglomerates, sandstones and shales which at- hDana, J. D., in U. S. Exploring Expedition, under command of Charles Wilkes, U. S. N., Philadelphia, vol. 10, 1838-1842. 2Willis, Bailey, Tacoma Folio, No. 54, U. S. Geological Survey, 1896. 3Arnold, Ralph, Bulletin Geological Society of America, vol. 17, pp. 451-468, September, 1906.Vol. VI] WEAVER—POST-EOCENE OF WESTERN WASHINGTON 21 tain a thickness of 15,000 feet and have been folded into anticlines and synclines. Upon the basis of faunal evidence he states that the fossils of the formation indicate that the basal portion of the series is Oligocene in age, while the upper part is certainly Miocene. Since the separation of the two members will necessarily have to be made on paleontological grounds and will require a more detailed study of the material in hand than time has yet permitted, the term “Oligocene-Miocene series” will be used temporarily to designate the age of the beds. Arnold applied the term to this formation and recognized five faunal zones within it. Further mention is made concerning the occurrence of Oligocene and Miocene fossils at Restoration and Beans points, just west of Seattle, by Dr. Ralph Arnold4 and Dr. W. H. Dali.5 A paper published in 1908 by A. B. Reagan*5 and entitled “Some Notes on the Olympic Peninsula,” describes the Tertiary rocks occurring in certain localities along the north and west sides of the Olympic Peninsula. Several new species of mollusks are described and figured. In 1911, the writer, in a preliminary paper on the Tertiary of western Washington, described in a general way the distribution of the Miocene formations within the state. The following subdivisions were made: Lincoln formation of Oligocene age; Blakeley, Wahkiakum and Chehalis formations of Lower Miocene age, and the Montesano of Upper Miocene. Since the appearance of that paper, more detailed field work has been done by the writer. As a result, a large portion of the Chehalis formation is now included within the Wahkiakum and Montesano formations, and another division intermediate between the Lincoln and Blakeley is introduced, namely, the Porter.7 The area along the western border of the Olympics represented upon the map accompanying the report as undifferentiated Lower Miocene, is of probable Jurassic age and is now referred to as the Hoh formation. ^Arnold, Ralph, Professional Paper No. 47, U. S. G. S., “The Tertiary and Quaternary Pectens of California,” Washington, 1905. 5Dall, W. H., Professional Paper No. 59, U. S. G. S., “The Miocene of Astoria and Coos Bay, Oregon,” Washington, 1906. 6Reagan, A. B., “Some Notes on the Olympic Peninsula,” Kansas Acad. Sci. Geological Papers, pp. 131-238, 1908. 7Weaver, C. E., “A Preliminary Report on the Tertiary Palaeontology of Western Washington,” Bulletin No. 13, Washington Geological Survey, 1911.22 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. The most recent paper on the Tertiary of western Washington is by Arnold and Hannibal8 on the Marine Stratigraphy of the North Pacific Coast of America, published in 1913. A four-fold division of the Oligocene is recognized. The oldest is represented by the Sooke formation of southwestern Vancouver Island. This is followed by the San Lorenzo, Seattle and Twin River formations. Above this is the Monterey, which is thought to be in part Oligocene and possibly in part lower Miocene. The upper Miocene strata, which are described as occurring on the south and west portions of the Olympic Peninsula, are believed to be the equivalent of the Empire formation of Coos Bay, Oregon. GEOGRAPHIC DISTRIBUTION The Oligocene and Miocene deposits of western Washington exist in three separate areas. The largest and most representative area occupies the northern half of the Puget Sound basin and the north border of the Olympic Peninsula. A second area embraces the western portion of the Chehalis and Willapa river valleys in the southwestern part of the state. A third area constitutes a belt ranging from five to fifteen miles in width and trending east and west along the north shore of Columbia River. Within the Puget Sound basin and along the northern portion of the Olympic Peninsula, Miocene sediments are for the most part more or less heavily covered with deposits of glacial drift. They appear in the form of low sea cliffs along the shores of the entrance to the Bremerton Navy Yard, in the streets in the southern portions of the city of Seattle, and along the northern slopes of the Newcastle Hills. Along the north border of the Olympic Peninsula rock exposures appear almost continuously from Cape Elattery eastward to Port Crescent. Similar deposits occur within and along the shores of portions of the Ouimper Peninsula south of Port Townsend. The Puget Sound Basin Oligocene and Miocene area is separated from that of southwestern Washington by basalts and sedimentary rocks of Eocene age. From the southern margin of the Olympic Moun- 8Arnold, Ralph, and Hannibal, Harold, “Marine Stratigraphy of the North Pacific Coast of America/’ Proc. Amer. Philos. Soc., vol. 53, No. 212, November-December, 1913.Vol. VI] WEAVER—POST-EOCENE OF WESTERN WASHINGTON 23 tains in Chehalis County, Oligocene and Miocene formations extend southerly to the middle of Pacific County. Outlying residuals occur in western Thurston and Lewis counties. Similar deposits of post-Tejon age are present in Wahkiakum County and in the southwestern part of Pacific County. They have been cut by the Columbia River and their southern extension forms a part of the well-known series of outcrops occurring at Astoria, Oregon. No marine deposits of Oligocene or Miocene age are known to occur within the Cascade Mountains or within the great basin area of eastern Washington. In these regions deposits of corresponding age are of igneous or freshwater origin. SEDIMENTATION Erom the standpoint of stratigraphy the post-Tejon sediments occurring in the western part of the state are divided into two broad groups, separated by a well-marked unconformity. The older division includes deposits of Oligocene and lower Miocene age, while the younger involves sediments of upper Miocene and possibly lower Pliocene ages. During the Oligocene, embayments of the ocean were widely extended over western Washington with the exception of the central and western portions of the Olympic Peninsula. During the lower Miocene their extent became much smaller and by the opening of the upper Miocene they were almost entirely withdrawn. During the upper Miocene two small, shallow basins of deposition were formed. One of these existed in the basin of Grays Harbor and the other near the junction of Bogachiel and Solduc rivers in southwestern Clallam County. During the Eocene epoch, southwestern Washington was occupied by an embayment of the ocean which seems to have extended as far north as the middle portion of the present Puget Sound basin. This fact is indicated by the occurrence of narrow bands of marine strata interbeclded with those of purely brackish water origin. On the eastern shores of this embayment were situated extensive estuaries in which over 10,000 feet of brackish water sediments were deposited and which now form extensive outcrops in King, Pierce and Lewis counties. Igneous activity was characteristic of the larger z24 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. portion of the Tejon epoch but had almost entirely ceased by the opening of the Oligocene epoch. Near the close of the Eocene or at the opening of the Oligocene minor crustal movements brought about an encroachment of the marine waters into the Puget Sound basin and also into the present site of the Strait of Juan de Fuca. In southwestern Washington the oldest deposits of post-Eocene age occur west of the city of Centralia in the valley of Chehalis River. They consist of indistinctly bedded, sandy, gray shales containing a marine invertebrate fauna which will be referred to in this report as the Molopophorus lincolnensis zone. The strata containing the fauna may be referred to as the Lincoln horizon. At the present time the strata at this locality are approximately 1.000 feet in thickness. Away from stream, railway or wagon road cuts, rock exposures are largely obscured by a veneer of sands, clays and gravels, rendering it difficult to determine the exact areal limits of these beds. Fossiliferous strata outcropping in the banks of Olequah Creek near the town of Winlock and in the banks of Cowlitz River, six miles east of Vader, at the Graeco Ranch, may have been contemporaneously deposited with those at Lincoln Creek. The same may be true of the shales on Porter Creek north of the town of Porter in Chehalis County. They are unknown to the southwest in Pacific and Wahkiakum counties, as well as along the Strait of Juan de Fuca. Toward the close of deposition of the Lincoln sediments the Oligocene seas expanded and occupied portions of the Strait of Juan de Fuca and the Puget Sound basin, as well as most of southwestern Washington. By the close of the Oii-gocene epoch these deposits had attained a maximum aggregate thickness of 15,000 feet. They consist predominately of shales and sandy shales within which local beds of conglomerate and sandstone are occasionally interbedded. The thickest and most complete section of the Oligocene is to be found in northern Clallam County along the northern border of the Olympic Peninsula. The section measured between Cape Flattery and Clallam Bay possesses a thickness of 13,300 feet. The basal beds are situated at the west end of Wyatch Slough and the upper about half way between Neah Bay and Clallam Bay.Vol. VI] WEAVER—jPOST-EOCENE OF WESTERN WASHINGTON 25 Cape Flattery Section Top Feet Massive sandstone ................................................ 700 Chiefly shale, mostly concealed................................... 900 Massive sandstone ................................................ 175 Chiefly shale, mostly covered .................................... 800 Massive brown sandstone .......................................... 300 Concealed ........................................................ 500 Massive, medium grained, brown sandstone.......................... 300 Alternating bands of grayish brown shale and sandstone.......... 1,200 Brown sandstone .................................................. 200 Conglomerate ...................................................... 30 Brown sandstone ................................................... 50 Conglomerate ...................................................... 50 Conglomerate with interbedded layers of shale..................... 500 Coarse conglomerate .............................................. 300 Grayish brown shale .............................................. 700 Interbedded sandstone, shale and conglomerate..................... 200 Massive, pebbly conglomerate ..................................... 175 Hard, flinty shale................................................ 200 Sandstone with some interbedded shale ............................ 400 Interbedded massive sandstone and conglomerate.................... 450 Massive conglomerate .............................................. 30 Massive sandstone and intercalated conglomerate lense............. 300 Sandy conglomerate as exposed at Cape Flattery.................. 1,400 Interbedded sandstone and shale.................................. 150 Concealed, probably shale ........................................ 500 Laminated sandy shale ............................................ 200 Interbedded conglomerate and sandstone ........................... 250 Shale ............................................................ 350 Gritty sandstone with some interbedded shale...................... 250 Brown shale .................................................... 1,200 Brown banded sandstone............................................ 300 Total..................................................13,300 Structurally the strata just described are involved in the badly wrinkled southwestern limb of a syncline whose axis trends from Port Crescent northwesterly diagonally across the Strait of Juan de Fuca. The strata forming the northeasterly limb occur fringing the south coast of Vancouver Island. Deposits of Oligocene age are well developed in the low cliffs along the entrance to the Bremerton Navy Yard. These beds are a continuation of those occurring to the east at Alki Point and South Seattle, as well as along the north flanks of the Newcastle Hills. They have been sharply folded and deeply dissected by erosion, and later covered with deposits of glacial drift. The following generalized stratigraphic section has been constructed. The lowest beds exposed in the section outcrop at Orchard Point on the south side of Brem-26 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. erton Inlet and the highest beds along the north shore of the entrance to Blakeley Harbor. Top of Section Massive, coarse grained conglomeratic sandstones containing numerous lenticular bands of conglomerates. Occasional, narrow bands of clay shale are interbedded...................................... Sandy shales exposed beneath the waters of Blakeley Harbor......... Brownish gray, massive to slightly bedded, sandy shales as exposed along the south shore of Blakeley Harbor for a distance of one- half mile northwesterly............................; • • •:.... Shaly sandstone grading in places into a shale. Stratification well defined. Upper portion of this belt is located at Restoration Point .....................................................• ••• Shaly sandstones gradually becoming more sandy in depth. Bedding, very distinct ................................................. Massive, sandy shales.............................................. Massive, brownish-gray, coarse grained conglomeratic sandstones and interbedded bands of coarse conglomerate, the pebbles of which attain a diameter of two feet. Many of the pebbles are composed of basalt and others of light colored shale and sandstone.......... Feet 1,300 1,400 2,400 1,200 450 350 1,800 Total......................................................... 8,900 SEQUENCE OF FAUNAS In the report by Arnold and Hannibal on the “Stratigraphy of the North Pacific Coast,” deposits of Oligocene age are referred to as the Astoria Series. This series is divided into three divisions, namely: the San Lorenzo, Seattle and Twin River formations. The distinctions between these formations are largely based upon differences of faunas rather than upon lithologic grounds. In the opinion of the writer, it would be preferable to refer to these divisions as faunal zones rather than formations. The application of the term San Lorenzo formation to the deposits described as such in Washington seems hardly justifiable. The type locality for the San Lorenzo is located in the Coast Ranges of California. Whether the strata assigned to the San Lorenzo in western Washington represent a part, all, or more than that, belonging to the formation in California, has not been determined. Until such information is available it would be misleading to make such direct correlation. If future investigations should prove that the deposits were formed contemporaneously, the term could with justice be introduced. Studies made by the writer on Vol. VI] WEAVER—POST-EOCENE OF WESTERN WASHINGTON 27 faunas collected from the type localities of the Twin River and Seattle formations do not indicate sufficient grounds for making a separation. The Seattle formation is described as occurring on the south shore of the Strait of Juan de Fuca east of Twin River and east of Gettysburg. Detailed mapping in this region shows conclusively that the strata occurring there are involved in the east and west limbs of a syncline, and stratigraphical measurements prove the strata in question on each limb of this syncline to be identical. The arguments which have» just been made concerning the use of the term San Lorenzo in Washington, at present at least, may be applied to the introduction of the term Monterey and Empire. The exact use of the term Monterey has not been definitely agreed upon in California. As more and more detailed information is obtained there is divergence of opinion as to what is to be included within the meaning of the term Monterey. The faunas of Washington and Oregon are not at present sufficiently known to permit any direct correlations. Suggestions can be made, but it would seem preferable to the writer to use local names provisionally and to gather all the information possible concerning formations or faunal zones in Washington and later, when such information is at hand, both in California and Washington, to make direct correlations. Misunderstandings as to *what the writers are intending to convey will be less common. The gathering and recording of accurate information in the field is much more desirable than the attempt to make broad correlations with distant areas on insufficient and imperfect field data. After detailed studies have been made, such correlations can be made with confidence. In the meantime suggested similarities can be placed on record. Five distinct faunal zones can be recognized in the post-Tejon strata of western Washington. The following table will illustrate their sequence: Montesano horizon—Yoldia strigata zone. . . .Upper Miocene —unconformity— Wahkiakum horizqn—Area montereyana zone.Lower Miocene —unconformity—28 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. Blakeley horizon—Acila gettysburgensis zone....Oligocene Porter horizon—Turritella porterensis zone.....Oligocene Lincoln horizon—Molopophorus lincolnensis zone.. Oligocene Tejon group.......................................Eocene MOLOPOPHORUS LINCOLNENSIS ZONE The oldest post-Tejon fauna which has been recognized within western Washington occurs in sandy shales outcropping along the south bank of Chehalis River five to 10 miles west of the city of Centralia, in Thurston County. Fossils in this locality are fairly abundant and in an excellent state of preservation. An examination of the faunal lists from this region indicates that several of the species are identical with those occurring in the underlying Tejon Eocene. Among these are Brachysphingus clarki Weaver, Leda uvasana Dickerson, Crassatellites washingtoniana Weaver, Exilia dicker-soni Weaver, H emifusus washingtonianus Weaver, and Strep-sidura oregonensis Dali. The following species have been recognized as occurring in the rock bluffs along the south bank of Chehalis River west of Lincoln Creek. The strata containing the fauna may be referred to as the Lincoln horizon9 and the fauna itself as the Molopophorus lincolnensis zone. Pelecypoda Cardium lincolnensis Weaver Cardium lorenzanum (Arnold) Crassatellites washingtoniana Weaver Crassatellites cowlitzensis Weaver Crenella porterensis W eaver Leda uvasana Dickerson Leda lincolnensis Weaver Macrocallista pittsburgensis Dali A ucula washingtonensis Weaver Ostraea lincolnensis Weaver Solen curtus Conrad Solen parallelus Gabb Pit aria dalli Weaver Scaphapoda Dentalium stramincum Gabb Brachiopoda Tercbratalia, sp. 9The use of the term Horizon is in the sense of a deposit formed at a particular time and identified by distinctive fossils. 29 Gasteropoda Ampullina, new species Brachysphingus clarki Weaver Bittium lincolnensis Weaver Cancellaria, new species Calyptrcea washingtonensis Weaver Drillia stanfordensis (Arnold) Exilia dickersoni Weaver Hemifusus washingtoniana Vol. VI] WEAVER—POST-EOCENE OF WESTERN WASHINGTON Drillia hecoxi (Arnold) Lunatia cowlitsensis Dickerson Scaphander oregonensis Dali Surcula lincolnensis Weaver Strepsidura oregonensis Dali Strepsidura lincolnensis Weaver Molopophorus lincolnensis Weaver Turritella newcombi Merriam Weaver 1 he above listed fauna seems to have a closer affinity with that occurring at Porter Bluffs, about 20 miles to the west in Chehalis County, and designated in this report as the Turritella porterensis zone, than to the underlying Eocene. The most important species which occur in common are Cardium lorenzanum Arnold, Crenella porterensis Weaver, Dentalium conradi Dali, Drillia hecoxi (Arnold), Lunatia cowlitsensis Dickerson, and Mal'letia chehalisensis Arnold. Marcia oregonensis Conrad, Thyasira bisecta (Conrad), Thracia trapesoidea Conrad, and Phacoides acutilineatus (Conrad) are entirely absent from the Molopophorus lincolnensis zone. They are, however, among the most common species to be found in the Turritella porterensis and Acila gettys-burgensis zones. The following species are most characteristic of the Molopophorus lincolnensis zone: Cardium lorenzanum Arnold, Crassatellites ivashingtoniana Weaver, Lcda uvasana Dicker-son, Macrocallista piitsburgensis Dali, Pitaria dalli Weaver, Brachysphingus clarki Weaver, Exilia dickersoni Weaver, Lunatia cowlitsensis Dickerson, Drillia hecoxi (Arnold) and Strepsidura oregonensis Dali. A study of the faunas above listed indicates clearly a marked distinction between the Tejon fauna proper and the Molopophorus lincolnensis zone. A closer relation exists between the latter and the Turritella porterensis zone, although there are sufficient distinctions to warrant considering them separate faunal zones. 30 CALIFORNIA ACADEMY OF SCIENCES CProc. 4th Ser. TURRITELLA PORTERENSIS ZONE The type locality at which this fauna may be found is located in the cliffs along the north bank of Chehalis River near the mouth of Porter Creek, in Chehalis County. Exposures of the same strata also occur in the banks of the small creeks entering Chehalis River from the north in the vicinity of Porter Creek. The most common species appearing in this zone are Cardium lorenzanum Arnold, Crenella porterensis Weaver, Malletia chehalisensis Arnold, Marcia ore-gonensis (Conrad), Thracia trapezoidea Conrad, Thyasira bi-secta (Conrad), Phacoides acutilineatus (Conrad), Dnllia he-coxi (Arnold) and Turritella portcrensis Weaver. Such species as Acila gettysburgensis Reagan, Macrocallista vespcrtina (Conrad), Modiolus directus Dali, Panope generosa (Gould), Eudolium petrosum (Conrad), Turcicula washingtoniana Dali and Turritella blakeleyensis Weaver are absent. These species are, however, among the most characteristic occurring in the Acila gettysburgensis zone. It is possible that the Turritella porterensis zone may be represented beneath the lowermost beds of the Acila gettysburgensis zone south of Orchard Point at the Bremerton Inlet section. If so, it occurs between the lowest conglomerate belt of the Acila gettysburgensis zone and the underlying Eocene basalts near Port Orchard. This region is covered with glacial drift. The lower beds in the Clallam County area as exposed three miles west of Port Crescent may also represent this horizon. -d ACILA GETTYSBURGENSIS ZONE The type locality where this fauna may be found is in the sea cliffs about the entrance to the Bremerton Navy Yard. The lowermost strata occur at Orchard Point. The highest strata outcrop along the north shore of the entrance to Blakeley Plarbor. The total thickness of the beds here exposed is 8,900 feet. Detailed stratigraphic surveys show that the conglomerates at Orchard Point are below the sandstones and shales at Bean Point. The beds at Bean Point are about 2,000 feet below the fossiliferous beds at Restoration Point. The faunaVol. VI] WEARER—POST-EOCENE OF WESTERN WASHINGTON 31 in the lower portion of this section is almost identical with that at the well-known locality just north of Restoration Point. In other words, there appears to be but one faunal zone represented within the strata exposed between Orchard Point at the base of the section and the north shore of Blakeley Harbor at the top of the section. The most characteristic species of the Acila gettysburgensis zone are Acila gettysburgensis Reagan, Macrocallista vesper-tina (Conrad), Marcia oregonensis (Conrad), Modiolus rectus Dali, Panope generosa (Gould), Phacoides acutilineatus (Conrad), Spisula albaria (Conrad), Solemya ventricosta Conrad, Tellina oregonensis Conrad, Thracia trapezoidea Conrad, Thyasira bisecta (Conrad), Crepidula praerupta Conrad, Eudolium petrosum (Conrad), Miopleiona indurata (Conrad), Turcicula washingtoniana Dali and Turritella blakeleyensis Weaver. Such species as Acila gettysburgensis Reagan, Solemya ventricosta Conrad, Eudolium petrosum (Conrad) and Turcicula washingtoniana Dali appear for the first time in this zone. They are always among the most common species met with and are entirely absent from the Turritella porter-ensis and Molopophords lincolnensis zones. ARCA MONTEREYANA ZONE The recognition of a fauna characteristic of the Area mon-. tereyana zone was first mentioned as occurring in Wahkiakum County on the Alockaman River about 12 miles north of the town of Cathlamet. The strata are composed of sandstones and shales involved in a shallow synclinal trough. Deposits of sandstones and sandy shales outcropping along the Strait of Juan de Fuca from Pysht westerly to Clallam Bay, also contain a fauna belonging to this faunal zone. Similar faunas representing both deep and shallow water phases occur in the shales and sandstones in the Grays Harbor region. The sediments in which they occur were in part formerly referred to by the writer as the Chehalis formation.10 A complete list of the species occurring within this zone may be referred to in the faunal table on page 35. Among 10Bulletin No. 13, Washington Geological Survey, 1911.32 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. the more characteristic species occurring in this zone are Area montereyana Osmont, Chione securis (Shumard), Diplodonta parilis Conrad, Acila conradi Meek, Area trihneata Conrad, Marcia oregonensis (Conrad), Pecten propatulus Conrad, Panope generosa (Gould), Phacoides acutilineatus (Conrad), Spisula albaria (Conrad), Crepidula preempt a Conrad, Fu-sinus stanfordensis (Arnold), Polynices saxea Conrad, Sinum scopulosum (Conrad), Dentalimn conradi Dali, Aturia an-gustata Conrad, Pecten fucanus Arnold, Tellina arctata Conrad, Venericardia quadrata Dali, Venus olympidea (Reagan), Venus clallamensis (Reagan), Ficus clallamensis Weaver, Tellina nevadensis Anderson, Cancellaria dalliana Anderson, Cancellaria condoni Anderson, and Leda ochsneri Anderson. This fauna presents a very strong similarity to that occurring in the Monterey formation in California. YOLDIA STRIGATA ZONE The upper Miocene strata of western Washington everywhere rest with unconformity upon the older rocks. The fauna occurring within these strata is very different from that of the faunal zones just described. One of the most common and readily recognizable species among this fauna is Yoldia stri-gata Dali. It might be desirable to refer to this fauna as the Yoldia strigata zone. Among the more characteristic species belonging to this zone are Area trilineata Conrad, Cardium meekianum Gabb, Macoma astori Dali. Mulinia densata Conrad, Pecten coosen-sis Shumard, Solen sicarius Gould, Siliqua nuttallii Conrad, Yoldia strigata Dali. Argobuccinium cammani Dali, Chryso-domus imperalis Dali, Phalium aequisulcatum Dali, Sinum scopulosum (Conrad) and Scutella gabbii Remond. A complete list of the species occurring in this zone may be found in the faunal table. Strata containing fauna of the Yoldia strigata zone outcrop in the Chehalis valley in the vicinity of Grays Harbor, at the mouth of the Oueniult River and in the lower valley of the Ouillayute River. The faunas of the Ouillayute and Oueniult valleys may represent a slightly higher position thanVol. VI] WEAVER—POST-EOCENE OF WESTERN WASHINGTON 33 those of the Chehalis Basin. Detailed studies at each of those localities will be required to determine that point. No marine deposits are known to occur within the state younger than those near the mouth of the Queniult Basin ex-cept late Pleistocene beach sands around the shores of Puget Sound. CORRELATION Sufficient evidence is not as yet at hand to warrant a direct correlation of the faunas or faunal zones of western Washington with those of California. The great unconformity existing between the upper and lower Miocene is general throughout the Pacific coastal region. The faunas of both the upper and lower Miocene are distinctly different in California and Washington. The upper Miocene fauna of Washington appears to have its closest resemblance to the San Pablo of California, but more detailed evidence must be secured before such a definite correlation can be made. The Area montereyana zone of Washington appears to be the equivalent of the same zone in California. It is possible, however, that more or less may be included within the faunal zone in the north than in the south. The Molopophorus lincolnensis and the Turritella porterensis zones of Washington may be the equivalent of the Agasoma gravidum zone of California. It is possible that the Acila gettysburgensis zone is in part higher than the Agasoma gravidum zone in the south. CONCLUSIONS The post-Tejon formations of western Washington consist of shales and sandstones of marine origin. These deposits contain a well-developed fauna which at the present time is imperfectly known. The total maximum aggregate thickness of the sediments is approximately 20,000 feet. Five well-marked faunal zones are present, the uppermost of which is separated from the lower four by a well-marked unconformity and difference in character of species. This lineI 34 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. of separation is the division line between the upper and lower Miocene. The uppermost of the remaining four faunal zones is separated from the other three by well-marked faunal differences. It is lower Miocene in age while the three lower zones are Oligocene. The faunas of the Oligocene in western Washington show a gradual gradation from one zone into another. Insufficient evidence is as yet available to warrant making direct correlations with the post-Tejon zones of California, yet suggested similarities appear. POST-TEJON FAUNAL TABLE FOR WESTERN WASHINGTON The following table contains a list of the species occurring in the post-Tejon strata of western Washington. A large number of new’ and undescribed species are present, which are not included within this list. IPost-Tejon Faunal Table for Western Washington Molopophorus lincolnensis Zone Turritella porterensis Zone Acila gettysburgensis Zone Area montereyana Zone 2 a § r biimard X x 'hvnbnhjhf i nnrnd X X X X Pfirtfivi furn'yuK AtticiIH "P vet en -h e ct?h n m 1 Crabb X X X X X X 7 z> x'/ VJ C \A/ ParlaM nln/'hfl'yyifi'VIPM Q VvPflVPr X P c/tn/]1 ti onnhi RptTintin X X X P 'i/*nf vA/pnvpr X «i/im 1eznnne ci r vv pavpr X CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. Post-Tejon Faunal Table for Western Washington—(Cont.) Molopophorus lincolnensis Zone Turritella porterensis Zone Acila gettysburgensis Zone Area montereyana Zone Yoldia strigata Zone Recent Tejon formation of Washington Astoria Tunnel Point Beds Empire Agasoma gravidum Zone Area montereyana, California San Pablo Santa Margarita Etchegoin Semele, n. sp X Solemya ventricostata Conrad X X X Solen curtus Conrad X X Solen parallelus Gabb X X X Solen sicarius Gould X X X X Solen conradi Dali X X Spisula albaria (Conrad) X X X X X X X Spisula catilliformis Conrad X X X X Spisula praecursor Dali X X X X X X Tapes staleyi Gabb Tellina kincaidi Weaver Tellina merriami Weaver Tell-ina obruta Conrad X X X X X X Tellina nyeponensis Conrad X Tellina arctata Conrad X Tellina. ara.pnn.ia. Dali X X Tellina. mjm.l.a.na Pall X X Tellina mnpesta Conrad X X Tellina nevnrlensis And,ftrSOfl ... X X X Thvnrin tvn-hpznjdpn CnnTAn . . . X X X X X X X X a//7 tirn hiwrfn H,r»nr?irii . . . ^il inn n nuitnlii Conrad . . X X X /’/7'K/W/r zuhiPYifn i nnrAn . . X X X X X X in rh ph nl i spyi si 9 Vr\l rl j n nvporwn SshnwQrn X X X X X XZr\1/7 in im P\yff^sn t nnron X X X TZr\lz/Vn eiihirmyifqi z Aftn/nfi TZ/^/zW// ctviontn T^)q11 X X V nlz74n czr vw wi n w xm V Ch w Cl C vV pQVPT X SCAPHAPODA X X X X X X X X X Go Vol. VI] WEAVER—POST-EOCENE OF WESTERN WASHINGTONPost-Tejon Faunal Table for Western Washington—(Cont.) Go 00 Molopophorus lincolnensis Zone Turritella porterensis Zone Acila gettysburgensis Zone Area | montereyana Zone Yoldia strigata Zone Recent Tejon formation of Washington Astoria Tunnel Point Beds Empire Agasoma gravidum Zone Area montereyana, California San Pablo Santa Margarita Etchegoin GASTEROPODA Ampullina oregonensis Dali X X X Ampullina, n. sp X A rgobuccinum cammani Dali X X X Argobuccimum coosense Dali X X X Bathytoma bogachieli Reagan Bathytoma gabbiana Dali X Brachyspingus clarki Weaver Bitiium lincolnensis Weaver x X Buccinium bogachieli Reagan X Cancellaria washingtonensis Weaver X C'alyptraea jilosa (Gabb) X X X Calliosloma slantoni Arnold X C alyptraea washingtonensis Whaver X Calyptraea inornata (Gabb) X X X X X Chrysodomus clallamensis W^eaver X Calyptraea excentrica (Gabb) X X ('hrysodomus maxfieldi (Reagan) x Chrysodomus imperialis Dali x x X X Chrysodomus hair di Dali x X ( hrMsndomns pipanticus Reavan x CnVumhella pansa.'hat.a Da.11 x x Crrhidnla t)rincet)S Gonrad X X X X X C\irnnti'um. bn.n h.cn.m Da.ll X C're-hid'ul.a -hrrtemfata Gonrad X x X X x X X (1nwr?l 1nrin mwclcivi'i Annprsntl. X X X X C'/iurtUnri/i nwvinnrh.CM si s AA/Pfiver.. ( ’ n m r pitnr in tl nil! nw n Andprsnn ('nilindrrnui Mwim/ini Dali X X C'nll'i pc/fiw// /V/>//i 9:717 ^17 ?7 ? AA/P^VPr X x hl rwndnmfl nvifinldi WpavPT f '-iiwi n hi falirn tn Pann X X x X /Tv/7-w/»//n bdvnsn f'nnrad X X /"Xw/Zizi rbphnliwwi <1 Arnold X x Epitonium condoni Dali X CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. IPost-Tejon Faunal Table for Western Washington—(Cont.) Molopophorus lincolnensis Zone Turritella porterensis Zone Acila gettysburgensis Zone Area montereyana Zone Yoldia strigata Zone Recent Tejon formation of Washington Astoria Tunnel Point Beds Empire Agasoma gravidum Zone Area montereyana, California San Pablo Santa Margarita Etchegoin Epitonium rugiferum Dali X F.pitonium washingtonensis Weaver... X Euiinliwm. petirnswm (Conrad) X X Euliwia smithi Reagan X X Fulimn 'itin.shin.pt.onin.na Rpflpan Exilia dickersoni Weaver Tin sinus mnntpsnn.npn sis WftfLVfvr X X X T^m sinus stnnfcwdpn sis f Arnold^ X Tim sinus rfW'huIpntMS fCzOnrAfi). X X 77-7/ci 177/c /tvwhms T")a 11 X X T^villin berri'vi (Afnnld'l X X X THrus rbphnli spm sis \A/ p^vpt X X 77im s howmnnrb pm si s Wpqvpt 77V z“4/c r\vp or\Mpm si s ( nnrQn X X 77 i m c pi n 11 n \m pm si s W P3VP1" X 7*^ 514/4 44 4*4/dH4 Cd)/<7»4 i~1 PM C-f C WpQA/Pr X X X Hemifusus washingtoniana Weaver 7 4/14V)/> P4/ T 04/7/“ zr/^/c I loll X X X X 7x"»./"»-/•! Id zi4/4/ c* rifihrii I loll X X x X X X X X X X X X X X X X X X X X Polynices lewisii (Gould) X X X X X X X X X X X X X x X Go Vol. VI] WEARER—POST-EOCENE OF WESTERN WASHINGTONPost-Tejon Faunal Table for Western Washington—(Cont.) ________________________________________________________________________________© • Molopophorus lincolnensis Zone Turritella porterensis Zone Acila gettysburgensis Zone Area montereyana Zone Yoldia strigata Zone Recent Tejon formation of Washington Astoria Tunnel Point Beds Empire Agasoma gravidum Zone Area montereyana, California San Pablo Santa Margarita Etchegoin Scaphander oregonensis Dali X X X Surcula lincolnensis Weaver X Strepsidura oregonensis Dali X Strepsidura lincolnensis Weaver X Sinum scopulosum (Conrad) X X X X X Thais etchegoinensis Arnold X X Turris coosensis Dali X X X X Turris coli Dali X Turris cammani Dali X Turris fresnoensis Arnold Turris perversa Gabb X X X X Turris wynoochensis Weaver X Turcicula washingtoniana Dali X Turritella oregonensis Conrad X X X Turrilella porterensis Weaver X X Turritella blakeleyensis Weaver X Turritella newcombi Merriam x CEPHALOPODA Aturia angustata Conrad ECHINODERMATA Scutella gabbii Remond X X X X X X X X BRACHIOPODA 'lerebraLula oakvillensis Weaver X Terebratalia occidentalis Dali X flemithyris astoriana Dali X X CRUSTACEA Rrfldivnrfln remains. x X PROTOZOA Fnrnminifera .................. X X x X PISCES Teeth x X CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser.PROCEEDINGS OF THE CALIFORNIA ACADEMY OF SCIENCES Fourth Series Vol. VI, No. 3, pp. 41-52. May 6, 1916 III THE OLIGOCENE OF KITSAP COUNTY. WASHINGTON BY Charles E. Weaver Assistant Professor of Geology, University of Washington, Seattle INTRODUCTION The purpose of this paper is to place upon record the results obtained from geologic and paleontologic studies made in Kitsap County, Washington, along the north and south shores of the entrance to the Bremerton Navy Yard. Because of the isolated occurrence of pre-glacial outcrops, it seems desirable to select small areas of importance and to investi-• gate the geology of them in as much detail as possible. The area involved in this study is located six miles west of Seattle and is of special importance because of the occurrence there of the most complete and representative section of the Oligocene within the Puget Sound basin. With the exception of the exposures along the south side of the Strait of Juan de Fuca, it is the most complete within the state. The surface rocks in the larger portion of the Puget Sound basin are composed of deposits of glacial drift. In a number of small and isolated areas the older pre-glacial bedrock formations project up through the drift. Such exposures are usually found in the form of low sea cliffs or in the canyons of certain streams. The region under investigation is one of such areas. May 6, 191642 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. PREVIOUS INVESTIGATIONS At various times during the last 10 years reference has been made in the literature on west coast Geology to the presence of Oligocene and Miocene fossils at Restoration and Beans points on the north shores of Richs Passage. In 1904 Dr. Ralph Arnold, in his paper on the Tertiary and Quaternary Pectens of California, refers to certain “shales near Beans Point, King County1,” which contain a fauna of probable Oligocene age. Note is made concerning the occurrence of Pecten peckhami Gabb at U. S. G. S. localities 4112a and 4113, between Beans and Restoration points, King County. Pecten clallamensis Arnold is noted at Beans Point and “is associated with Terebratula, sp., Turritella, sp., Marginella or Erato, sp., Natica or Lunatia, sp., Glycimeris, sp., and Astyris, sp.” In 1909, Dr. W. H. Dali2, in his paper on the Miocene of Astoria and Coos Bay, Oregon, mentions the occurrence of Oligocene strata at Port Blakeley and Restoration Point, opposite Seattle. The following species are listed from these localities: Ampullina mississippiensis Conrad, Miopleiona in-durata Conrad, Titrcicula washingtoniana Dali and Aturia an-gustata Conrad. In 1911, the writer3 4 in a preliminary paper on the Tertiary Palaeontology of Western Washington described the occurrence of lower Miocene strata and fossils in the Restoration Point and Blakeley Harbor area and provisionally referred to them as the Blakeley formation. These strata were recognized as a part of an extensive lower Miocene series involved in the north flank of a well-defined anticline trending from east to west across the Puget Sound basin. The most recent report involving a discussion of the Restoration Point area is to be found in a paper by Arnold and Han- of America, published in 1913. A three-fold division of the Oligocene is recognized: The San Lorenzo or lower, the 1Arnold, Ralph, The Tertiary and Quaternary Pectens of California. Professional Paper 47, U. S. Geological Survey, 1906. 2Dall, Dr. W. H., The Miocene of Astoria and Coos Bay, Oregon. Professional Paper 59, U. S. Geological Survey, 1906. sWeaver, C. E., A Preliminary Report on the Tertiary Palaeontology of Western Washington. Bull. 13, Wash. State Geol. Surv., 1912. 4Arnold, Ralph, and Hannibal, Harold, The Marine Tertiary Stratigraphy of the North Pacific Coast of America, Proc. Am. Phil. Soc., vol. 52, pp. 573-579, 1913.Vol. VI] WEAVER—OLIGOCENE OF KITSAP CO., WASH. 43 Seattle or middle, and the Twin River or upper. The lower and middle divisions are stated to occur at Restoration Point. The San Lorenzo formation is described as the “sandstones overlying the lower Astoria basalts west of Port Orchard Sound and forming the lower half of the Bainbridge Island section of the Seattle monocline.” The Seattle formation is said to consist “of the upper beds of the northward dipping Seattle monocline extending from Restoration Point on Bainbridge Island across Admiralty Inlet.” The Twin River formation is not believed to occur in the Puget Sound basin. In none of the investigations so far undertaken has an attempt been made to work out the details of the stratigraphy. GENERAL STATEMENT CONCERNING THE MA- RINE TERTIARY IN WESTERN WASHINGTON* All of the pre-glacial areal outcrops in the western part of the state with the exception of the central and western portions of the Olympic Peninsula and the San Juan Islands are of Tertiary age. Both sedimentary and igneous rocks are present. They were formed during the Eocene, Oligocene and Miocene epochs. With the exception of possible marine sediments in the extreme western portion of Chehalis County, no rocks of definite Pliocene age are known to exist. The history of the Pliocene in western Washington must be sought in terms of diastrophism and erosion. During the Eocene epoch there were formed deposits of marine, brackish and freshwater origin. Intercalated with these are lavas and tuff of andesitic character. These deposits attain a total maximum aggregate thickness of at least 10,000 feet. The marine invertebrate faunas occurring within these strata indicate that only the Tejon or upper Eocene is present in western Washington. Five distinct marine faunal zones can be recognized in the post-Eocene formations of western Washington: Yoldia strigata zone......................Upper Miocene Area montereyana zone.....................Lower Miocene *A detailed report on the “Tertiary Formations of Western Washington” by the writer will be issued as a bulletin of the publications of the Washington State Geological Survey. Accompanying this report are detailed areal and structural geological maps of the western portion of the state.44 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. Acila gettysburgensis zone..................Upper Oligocene Turritella porterensis zone................Middle Oligocene Molopophorus lincolnensis zone..............Lower Oligocene The strata in which these zones are contained are referred to in this paper as horizons, the term being used in the sense of a deposit formed during a certain time and identified by certain distinctive fossils. The type locality for the Molopophorus lincolnensis zone occurs along the south bank of Chehalis River near the mouth of Lincoln Creek. This fauna possesses many characteristics in common with the underlying Tejon Eocene, but more with the Turritella porterensis zone above. The strata characterized by this fauna may be referred to as the Lincoln horizon.* The Turritella porterensis zone is to be found well represented in the sandstone bluffs along the north bank of Chehalis River near the junction of Porter Creek. The sediments containing this fauna have been referred to as the Porter horizon. Among the more characteristic fossils occurring in this fauna are Phacoides acutilineatus (Conrad), Thyasira bi-secta (Conrad), Thracia trapezoidea Conrad, Cardium lorenzanum (Arnold), Turritella porterensis Weaver, Drillia stan-fordensis (Arnold) and Malletia chehalisensis Arnold. It is possible that the upper portion of this zone may be represented in the extreme lower portion of the section at Orchard Point. The type section of the third or Acila gettysburgensis zone occurs within the strata exposed near the entrance to the Bremerton Navy Yard. Most of the faunas from the post-Tejon and pre-glacial strata in the Puget Sound basin belong to this zone. The sandstones and shales containing the fauna form the Blakeley horizon. The fourth division, or Area montereyana zone, is to be found in the sandstones outcropping along Alockaman River in Wahkiakum County, 12 miles north of Cathlamet. It also occurs in the sandstone and shale exposures along the south *There is considerable doubt in the writer’s mind as to the wisdom of using the term, horizon. In geological literature it is often used in a very loose sense. Sufficient geological field evidence is not available to warrant the term formation as yet. Without the introduction of an entirely new word to express the idea of an assemblage of varying types of rocks all of which are characterized by the same distinctive fauna, it becomes necessary to choose one which has been used most nearly in such a sense.Vol. VI] WEAVER—OLIGOCENE OF KITSAP CO., WASH. 45 shore of the Strait of Juan de Fuca between Pysht and Clallam Bay. The strata are referred to as the Wahkiakum horizon. Resting unconformably upon the Oligocene and lower Miocene sediments are shallow water deposits of upper Miocene age containing a distinctive fauna which may be referred to as the Yoldia strigata zone, or Montesano horizon. STRATIGRAPHY From the western spur of the Cascade Mountains in King County, a prominent spur extends nearly due west into the Puget Sound basin. This spur includes the Issaquah and Newcastle hills. From Lake Washington it trends westerly through Seattle as a pre-glacial and, in part, submarine topographic feature. It crosses the Sound a little to the south of Bainbridge Island and reappears in the Bald Hills of central Kitsap County. Structurally this ridge is of anticlinal origin. Sedimentary and volcanic rocks of Eocene and Oligocene age are involved within it. Extensive erosion has deeply cut into it so that the Oligocene strata have been completely removed from the axis. The core is largely composed of Eocene basalts together with brackish water and marine sediments. The coal measures at Issaquah and Newcastle, together with the sandstone and shales between Duwamish and Renton, belong to this phase. The basalts which outcrop on the shores of Sinclair . Inlet, as well as those southwest of Bremerton in the Bald Hills, belong to the basaltic phase of the Tejon-Eocene. Resting unconformably upon the Eocene rocks and forming a part of the north flank of the anticline just mentioned, are sandstone and shales of Oligocene age. These strata are exposed in the north slopes of the Newcastle Hills, in the street cuts of Columbia City and Georgetown (both of which are within the city limits of Seattle), along the shores of Bailey Peninsula and at Alki Point. West from Seattle they outcrop at the water’s edge at the south end of Bainbridge Island and along the south shores of Richs Passage. They appear for a distance of a mile along both shores of the narrow channel northwest of Bremerton near Tracyton. To the north of these Oligocene outcrops, the only formations within the county exposed at the46 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. surface are deposits of glacial drift. Presumably they are involved in a broad synclinal basin beneath the glacial drift of northern Kitsap County. The evidence for such a suggestion is to be found to the northwest on the Quimper Peninsula between Quilcene and Port Townsend. In that region the same Oligocene strata resting unconformably upon the Eocene basalts exist in a broad synclinal fold whose axis trends south-easterly and passes beneath the glacial covering of northern Kitsap County. It can be seen from the foregoing statements that the Oligocene beds exposed at the entrance to the Bremerton Navy Yard are a representative part of the Oligocene formations of the Puget Sound basin and as such are worthy of detailed study. In the investigation of this particular region transit surveys were made along the shore lines wherever pre-glacial formations were exposed. All observations taken on the strike and dip of the strata were tied in to these traverses. Stratigraphic sections were also made with the aid of the transit. The distribution of the Oligocene strata as exposed along the shore lines, as well as the structural data, may be seen by referring to Fig. 1. The Oligocene strata of this region are entirely of sedimentary origin. The Eocene lavas upon which these sediments rest are exposed about two miles southwest of Bremerton on the west shore of Sinclair Inlet. The position on the surface of the contact between the Eocene andesites and the Oligocene sediments in this region is concealed beneath deposits of glacial drift. Many of the pebbles forming the basal conglomeratic phases of the Oligocene strata are composed in part of the older andesite. The lowermost strata exposed in this area outcrop at Orchard Point. The highest occur along the north shore of the entrance to Blakeley Harbor. The total thickness of the deposits as exposed between the lower and uppermost beds is approximately 8900 feet. The following generalized stratigraphic column is constructed from observations taken along the section (B-B') :Vol. VI] WEAVER—OLIGOCENE OF KITSAP CO., WASH.48 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. Top of Section _ Feet Massive, coarse-grained conglomeratic sandstones containing numerous lenticular bands of conglomerate. Occasional narrow bands of clay shale are interbedded. The eastward continuation of the conglomerates appears in the outcrops at Blakeley Rocks. These strata persistently pitch to the north at very steep angles and extend as outcrops from the north shore of Blakeley Harbor northerly for 1500 feet.... 1,300 (A) Sandy shales exposed beneath the waters of Blakeley Harbor.. 1,400 (B) Brownish gray, massive to slightly bedded, sandy shales as exposed along the south shore of Blakeley Harbor for a distance of one-half mile northwesterly. Five hundred feet stratigraphically above the beds exposed at Restoration Point is an excellent fossil locality, No. 13................. 2,400 (C) Shaly sandstone grading in places into a sandy shale. Bedding planes are commonly well defined. The top of this belt is located at Restoration Point................................... 1,200 (D) Shaly sandstone gradually becoming more sandy in depth. Bedding planes, very distinct....................................... 450 (E) Massive, sandy shales. Bedding planes, fairly distinct. F'ossil locality No. 305............................................... 350 (F) Massive, brownish gray, coarse-grained conglomeratic sandstones with interbedded bands of coarse conglomerate, the pebbles of which attain a diameter of two feet. Many of the pebbles are composed of andesite and others of light colored shale and sandstone ........................................ 1,800 (G) Total thickness ........................................ 8,900 The westerly continuation of the strata as exposed in the above section reappears in cross-section A A’. The upper beds as exposed at Point Glover appear to be the equivalent of those in belt (C). The extreme upper portion of belt (G) as exposed at Orchard Point is the westerly continuation of the narrow conglomeratic layers occurring just east of Beans Point on the south end of Bainbridge Island. The conglomerates outcropping at Quarry Point are the equivalent of those exposed at Middle Point, hrom Middle Point they cross Richs Passage and appear in the cliffs at Fort Ward on the south shore of Bainbridge Island. At this point they become less conglomeratic and more sandy. Near Restoration Point they are the equivalent of the upper portion of belt (D). The shales and sandstones exposed between Point Glover and Middle Point are to be correlated with the sandy shales in beltVol. VI] WEARER—OLIGOCENE OF KITSAP CO., WASH. 49 (C). The conglomerates in belt (A) and the shales in belt (B) do not appear on the south side of Richs Passage. It is possible, however, that the conglomeratic sandstones and interbedded shales near Tracyton and Phinney Point are the equivalents of those in belts (A) and (B). The following stratigraphic section has been measured between the basal beds at Orchard Point and the higher beds exposed at Point Glover along section (A A’) : Top of Section at Point Glover Feet Massive, sandy shale with poorly defined bedding planes...... 150 Shaly sandstone ................................................. 70 Brownish gray, sandy, clay shale................................ 500 Massive, brown sandstone........................................ 100 Gray, sandy shale............................................ 45 Brown, massive, coarse-grained sandstone......................... 60 Interbedded shale and sandstone, shale predominating......... 140 Massive sandstone ............................................... 80 Thickly bedded shale ........................................... 200 Alternating beds of thinly bedded shales and sandstones...... 520 Banded sandstone and shale, shale predominating.................. 40 Banded shale and sandstone, shale predominating.............. 20 Thinly bedded, gray shale ....................................... 70 Massive, brownish gray sandstone ................................ 40 Thinly bedded shale ............................................. 30 Massive, brown sandstone ....................................... 300 Mainly shale with a few narrow bands of sandstone............ 200 Mainly sandstone with a few* narrow bands of shale interbedded. 30 Mainly thin bedded, clay shale without distinct bedding...... 900 Massive, brown sandstone..................................... 65 Alternating layers of thinly bedded sandstones and shale with occasional bands of sandstones four to five feet in thickness .................................................... 90 Massive, brown sandstone, slightly banded...................... 75 Banded shale .................................................... 10 Thinly bedded shaly sandstone.................................... 40 Alternating bands of thinly bedded shale and sandstone....... 75 Massive, brown sandstone ........................................ 20 Massive, brown gritty sandstone......... .................... 35 Gray shale possessing well-defined bedding ..................... 100 Massive, brown sandstone containing bands of shale........... 30 Mostly shale with a few bands of interbedded sandstone. Strata in part concealed....................................1,800 Thinly bedded shale somewhat massive in places and containing occasional bands of sandstones averaging one foot in thickness .....................>......... ................... 320 Massive, brownish gray sandstone containing pebbly and conglomeratic bands ...............................•......... 1,400 Massive conglomerates composed of pebbles ranging up to two feet in diameter and composed in part of altered andesite.. 15 Massive, gritty sandstone ....................................... 60 Conglomerate .................................................... 15 Massive, gritty brown sandstone. These are the lowest strata exposed in the Bremerton Inlet area.......................... 70 Total thickness ...................................... 8,71550 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. FAUNAL RELATIONS The invertebrate fauna occurring in the sedimentary rocks just described is entirely of marine origin. Altogether 42 species are present. In the lower beds outcropping at Orchard Point and represented by belt (G), the only species found are Cardium lorenzanum (Arnold), Nucula, sp., and Tellina oregonensis Conrad. In the following table the fauna listed from locality No. 13, comes from the sandy shales north of Restoration Point in belt (C). Locality No. 304 is located at the west end of Quarry Point and the fauna occurring there belongs to belt (C). Locality No. 305 occurs at Beans Point in the lower portion of belt (F). The most characteristic species occurring in this region are Acila gettysburgensis Reagan, Macrocallista vespertina (Conrad), Marcia oregonensis (Conrad), Modiolus in flatus Dali, Panope generosa (Gould), Phacoides acutilineatus (Conrad), Solemya ventricostata Conrad, Thracia trapezoidea Conrad, Eudolium petrosum Conrad and Turcicula washingtoniana Dali. The most fossiliferous portion of the formation is in belt (C). The fauna occurring in belt (F) except in the number of species does not differ greatly from that in belt (C). The conglomerates and coarse-grained sandstones composing the lowermost beds of the section as exposed at Orchard Point is almost entirely barren of fossils. This lower belt may correspond to the upper part of the Porter horizon or Turritella porterensis zone as exposed in the Chehalis Valley. The fauna appearing in belt (C) at Restoration Point is almost identical with that occurring to the east within the city of Seattle, and in the sandy shales on the north slopes of the Newcastle Hills. It may also be correlated with that at Fiddlers Bluff about two miles south of the town of Snohomish. The shales and sandy shales outcropping between Pysht and Gettysburg are also to be referred to this horizon or faunal zone. The following table gives the distribution of the marine fauna occurring in the Bremerton Inlet area:Vol. VI] WEAVER—OLIGOCENE OF KITSAP CO., WASH. 51 Faunal List > A cila gettysbzirgensis Reagan..... Area, sp........................... Cardium lorenzanum (Arnold)....... Chione cathcartensis Weaver........ Crenella porterensis Weaver....... Leaa chehalisensis Weaver.......... Macrocallista vespertina (Conrad).. Marcia oregonensis (Conrad)....... Modiolus directus Dali............ Modiolus inflatus Dali............ Mytilus sammammishensis Weaver Nucula conradi Meek................ Ostraea, sp........................ Panope generosa (Gould)........... Peden peckhami Gabb............... Peden, sp......................... Phacoides acutilineatus (Conrad). . Solen curtus Conrad................ Solemya ventricostata Conrad....... Spisula albaria (Conrad)........... Tellina obruta Conrad............. Tellina oregonensis Conrad........ Thracia trapezoidea Conrad........ Thyasira biseda Conrad............ Yoldia impress a Conrad........... Yoldia oregona Shum............... 13 * * * * * * * * * * * * 304 305 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * GASTEROPODA Ampullina oregonensis Dali........................... Crepidula praempta Conrad............................ Epitonium, sp........................................ Eudolium petrosum (Conrad)........................... Fusinus, sp.......................................... Miopleiona indurata (Conrad)......................... Natica oregonensis Conrad............................ .Scaphander oregonensis Dali......................... Turcicula washingtoniana Dali........................ Turritella blakeleyensis Weaver...................... Turritella newcombi Merriam.......................... Turris fresnoensis (Arnold).......................... SCAPHOPODA Dentalium conradi Dali............................... CEPHALOPODA Aturia angustata Conrad.................... BRACHIOPODA Hemithyris astoriana Dali.................. CONDITIONS OF DEPOSITION At the close of the Tejon epoch the Eocene deposits were differentially uplifted. Early in the Oligocene new embayments were formed. The seas of the northern part of the 52 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. Puget Sound region were disconnected from those to the south in the Grays Harbor area. The shore line of the present site of the Puget Sound embayment appears to have existed somewhere between Seattle and Tacoma and to have extended in an east to west direction from the present site of the Cascade Mountains to the present location of the Olympics. The present contact between the Eocene and Oligocene formations in the Bremerton Inlet, or Kitsap County, area is much farther north than the original southerly limits of the shore line. The strata have been tilted from their original horizontal position into a nearly vertical position and as a result those sediments which formerly extended to the south have been entirely removed by erosion. The lithologic character of the sediments and the faunas occurring within them indicate that they were deposited in shallow to moderately deep water. No products of direct volcanic origin were poured out in this region during the Oligocene epoch. This is in sharp contrast to the conditions of volcanic activity during the Tejon. CONCLUSIONS The area involved in this investigation is of special importance because within it occurs one of the most complete sections of Oligocene strata to be found in the state. There are approximately 8900 feet of conglomerates, shales and sandstones which are entirely of marine origin and rest unconformably upon older Tejon basalts and sediments. The contact in this area between the Tejon and Oligocene is obscured by deposits of glacial drift. The Oligocene strata form the north flank of an extensive east to west trending anticline, the axis of which has been deeply dissected by erosion. A marine fauna of 44 invertebrates is now known. The horizon represented is upper Oligocene. The fauna is a unit from base to top of section and is termed the Acila gettysburgensis zone.PROCEEDINGS Fourth Series VOLUME I Expedition of the California Academy of Sciences to the Galapagos Islands, 1905-1906. Pages 1-6. I. Preliminary Description of Four New Races of Gigantic Land Tortoises from the Galapagos Islands. By John Van Denburgh. {Issued December 20, 1901}..................... Pages 7-288. II. A Botanical Survey of the Galapagos Islands. By Alban Stewart. Plates i-xix. {Issued January 20, 1911},.. Pages 289-322. III. The Butterflies and Hawk-Moths of the Galapagos Islands. By Francis X. Williams. Plates xx-xxi. {Issued October 7, 1911}..................................... Pages 323-374. IV. The Snakes of the Galapagos Islands. By John Van Denburgh. Plates xxn-xxx. {Issued January 11,1912} Pages 375-404. V. Notes on the Botany of Cocos Island. By Alban Stewart. Plates xxxi-xxxiv. {Issued January 19,1912} Pages 405-430. VI. The Geckos of the Galapagos Archipelago. By John Van Denburgh. {Issued April 16, 1912}................ Pages 431-446. VII. Notes on the Lichens of the Galapagos Islands. By Alban Stewart. {Issued December 11, 1912},....... VOLUME II, Part I Expedition of the California Academy of Sciences to the Galapagos Islands, 1905-1906. Pages 1-132. VIII. The Birds of the Galapagos Islands, with Observations on the Birds of Cocos and Clipperton Islands (Columbiformes to Pelecaniformes). By Edward Winslow . Gifford. Plates i-vii. {Issued August 11, 1913}......... Pages 133-202. IX. The Galapagoan Lizards of the Genus Tropidurus; with Notes on the Iguanas of the Genera Conolophus and Amblyrhyncus. By John Van Denburgh and Joseph R. Slevin. Plates viii-xi. {Issued September 19, 1913}, Pages 203-374. X. The Gigantic Land Tortoises of the Galapagos Archipelago. By John Van Denburgh. Plates xii-cxxiv. {Issued September 30, 1914}.................................. VOLUME III Pages 1-40. A Further Stratigraphic Study in the Mount Diablo Range of California. By Frank M. Anderson. Plate I. {Issued October 31, 1908}............................................ Pages 41-48. Description of a New Species of Sea Snake from the Philippine Islands, with a Note on the Palatine Teeth in the Proteroglypha. By John Van Denburgh and Joseph C. Thompson. {Issued December 31, 1908} Pages 49-56. New and Previously Unrecorded Species of Reptiles and Amphibians from the Island of Formosa. By John Van Denburgh. {Issued December 20, 1909}......................... Pages 57-72. Water Birds of the Vicinity of Point Pinos, California. By Rollo Howard Beck. {Issued September 11, 1910}............ Pages 73-146. The Neocene Deposits of Kern River, California, and the Temblor Basin. By Frank M. Anderson. Plates il-xin. {Issued November 9,1911}..................................... Pages 147-154. Notes on a Collection of Reptiles from Southern California and Arizona. By John Van Denburgh. {Issued January 11, 1912}....................................•....... Pages 155-160. Notes on Some Reptiles and Amphibians from Oregon, Idaho and Utah. By John Van Denburgh. {Issued January 11, 1912}............................................ Pages 161-182. Geologic Range of Miocene Invertebrate Fossils of California. By James Perrin Smith. {Issued April 5, 1912}... Pages 183-186. Description of a New Genus and Species of Salamander from Japan. By Surgeon J. C. Thompson, U. S. Navy. Plate xiv. {Issued May 3, 1912} ............................. .50 .50 .35 .35 .25 & •> i/ /' - • .00 .50 2.00 .35 .25 .25 .25 1.00 .25 .25 .25 .25 1PROCEEDINGS Fourth Series VOLUME m—Continued Pages 187-238. Concerning Certain Species of Reptiles and Amphibians from China, Japan, the Loo Choo Islands, and Formosa. By John Van Denburgh. {Issued December 16, 1912.}.......... Pages 259-264. Notes on Ascaphus, the Discoglossoid Toad of North America. By John Van Denburgh. {Issued December 21, 1912).................................................. Pages 265-390. A Distributional List of the Mammals of California. By Joseph Grinnell. Plates xv-xvi. {Issued August 28, 1913} Pages 391-454. A List of the Amphibians and Reptiles of Arizona, with Notes on the Species in the Collection of the Academy. By John Van Denburgh and Joseph R. Slevin. Plates xvii-xxviii. {Issued November 5,1913)........................... VOLUME IV Pages 1-13. I. Report of the President of the Academy for the Year 1913. II. George Davidson. {Issued April 8, 1914) ...... Pages 15-112. III. Neocene Record in the Temblor Basin, California, and Neocene Deposits of the San Juan District. By Frank M. Anderson and Bruce Martin. Plates I-X. {Issued December 30, 1914)......................................... Pages 113-128. IV. The Fauna of the Siphonalia sutterensis Zone in the Roseburg Quadrangle, Oregon. By Roy E. Dickerson. Plates xi-xii. {Issued December 30, 1914) ................. Pages 129-152. V. Reptiles and Amphibians of the Islands of the West Coast of North America. By John Van Denburgh and Joseph R. Slevin. {Issued Decernber 30,1914)............... Pages 153-160. VI. The Pocket Gopher of the Boreal Zone on San Jacinto Peak. By J. Grinnell and H. S. Swarth. {Issued Dece t, ber 30. 1914)............................... VOLUME V Pages 1-31. I. Report of the President of the Academy for the year 1914. II. Report of the Director of the Museum for the year 1914. (Issi ed Mar.h 26, 1915}........... Pages 33-98. III. Fauna of the Type Tejon: Its Relation to the Cowlitz Phase of the Tejon Group of Washington. By Roy E. Dickerson. Plates I-XI. {Issue June 15, 1915).............. Pages 99-110. IV. A list of the Amphibians and Reptiles of Utah, with Notes on the Species in the Collection of the Academy. By John Van Denburgh and Joseph R. Slevin. Plates xii-xiv. {Issued June 15, 1915)..................................... Pages 111-161. V. Description of a new subgenus (Arborimus) of Phenacomys, with a Contribution to Knowledge of the Habits and Distribution of Phenacomys longicaudus. By Walter P. Taylor. Plate xv. {Issued December 30, 1915)............ Pages 163—193. VI. Tertiary Deposits of Northeastern Mexico. By E. T. Dumble. Plates xvi and xix. {Issued December 31,1915). Pages 195-223. VII. Report of the President of the Academy for the Year 1915. VTII. Report of the Director of the Museum for the Year 1915. May 4, 1916) ... VOLUME VI Pages 1-17. I. Eocene of Lower Cowlitz River Valley, Washington. By Charles E. Weaver. Plate 1. {Issued May 6. 1916). Pages 19-40. II. The Post-Eocene Formations of Western Washington. By Charles E. Weaver. {Issued May 6, 1916). Pages 41-52. III. The Oligocene of Kitsap County, Washington. By Charles E. Weaver. (Issued May 6, 1916). Price for the three papers............................................... .50 .25 1.00 .75 .25 1.00 .50 .25 .25 .25 .50 .25 .50 .50 .25 .50 The Academy cannot supply any of its publications issued before the year 1907, its entire reserve stock having been destroyed in the conflagration of April, 1906. I 1 4