ae ee TH *A Mr. H. Y. L. BROWN, Government Geologist. oN Adelaide + E. BRISTOW, GOVERNMENT PRINTER, NORTH-TERRACE. ake ; BIOQ1.) FU @ 543.2 | OO he? in en \ VY, SOUTH AUSTRALIA. \ REPORTS ON COAL-BEARING AREA IN NEIGHBORHOOD OF LEIGH'S CREEK, Wc. Government Geologist’s Department, Adelaide, South Australia, September 9th, 1891. Sir—I have the honor to submit to youa preliminary report on the coal-bearing area in the neighbor- hood of Leigh’s Creek, with map and sections explanatory of the geological formations. Also a description of some Silurian and Mesozoic fossils, by Mr. R. Etheridge, jun., F.G.S., Palewontologist and Librarian, Geological Survey of New South Wales, and Palexontologist to the Australian Museum, Sydney, with illustrative plates. The Silurian fossils were procured by me in the Tempe Downs district, Central Australia, and the Mesozoic fossils from the bore at Leigh’s Creek, and were sent to Mr. Etheridge, in order that their geological age might be determined by a competent authority. I haye, &c., HENRY Y. L. BROWN, Government Geologist. REPORT ON THE COAL-BEARING AREA IN THE NEIGHBORHOOD OF MJLEIGH’S CREEK, SOUTH AUSTRALIA, WITH MAP AND SECTIONS EXPLANATORY OF THE GEOLOGICAL FORMATIONS, AND SHOWING THE POSITION AND EXTENT OF COUNTRY OCCUPIED BY THE COAL-BEARING ROCKS. The country under notice, which up to the present time I have not had opportunity to more than partially examine, includes the valley of Leigh’s Creek from Windy Creek, four miles south of Leigh’s Creek railway station to Farina, along the Northern railway line. ‘The distance of Leigh’s Creek from Ade- laide is 373} miles, and from Port Augusta 164 miles, by railway measurement. Leigh’s Creek rises in the ranges to the eastward of the railway, and flows with a more or less direct northerly trend, after being joined by the Mundy (a parallel creek) at Farina, into the Frome, near Mundowdna, which latter runs into Lake Eyre, some forty miles north of Hergott. In the neighborhood of Windy Creek the main range splits into two systems, one of these going to the north-east terminates at Mount Babbage, ninety or 100 miles away. The other bears in a north-westerly direction towards Callana Station, near which it ends, there being, however, a wide gap or break between Mount Playfair and Termination Hill, so that the range is not continuous. This system comprises what are known as the Mount Deception, Termination Hill, Willouran, and Mount Nor-West ranges. Those on@§the east are the Umberatana and other ranges. Leigh’s Creek railway station has an elevation of 770ft., Farina 300ft, and Hergott 152ft. above sea level [railway survey ]. ; Primary Rocks. The main range and its numerous spurs and offsets, together with a considerable area of flat or undulating country bordering them, consists of primary rocks of great age. The only fossils yet obtained occur in the crystalline limestone, near Parachillna and Blinman, and, according to Mr. Etheridge, they belong to the Cambrian period. These rocks consist of quartzites, sandstone, grits, conglomerates, claystones, clayslate, calcareous slates, flags, and dolomitic and other limestones. The strata are much upheaved, and in some places contorted and twisted; those forming the higher ranges have high dips, and are often vertical, while on the lower ranges the dip is sometimes as low as 5° to 10°, where they form portions of anticlinal arches or synclinal troughs. The strike as a general rule varies from E. and W. to N.W. and S.E. Commencing at the southern portion of the area under notice the following rock stratification has been observed :— Windy and Emu Creeks.—One section shows jointed beds of quartzite and calcareous quartzite on lime- stone, and slate on quartzite, sandstone, and quartzite, striking W.N.W. and dipping N.N.I. at from 80° to 85°, and having altogether a bed about 1,600ft. thick. . In the same neighborhood there are also outcrops of \, dolomitic limestone and calcareous slate. South A i > South of, at, and near Cutaway Hills.—Calcareous sandstone with pebbles (conglomeritic) on slaty conglomerate, on grit sandstone and quartzite: strike W ,dip 60° S. This conglomerate is stained with green carbonate of copper in many places. Sandstone and claystone, or kaolinized slate and grit, strike E., dip high 8. Claystones with brown iron oxide on joints and bedding: strike W., dip vertical and 85° N. Other Places near Leigh's Creek Railway Station and Neighborhood.—Calcareous slates and flags and dolomitic limestones, strike N.N.E.. dip 10° E.S.E. Dolomitie limestones and calcareous slates and flags, strike E. and W., dip 5° to 15° 'S. These rocks, with occasional bands of quartzite, are prevalent. Blue and yellow dolomitic limestone on purple flaggy clay slates, strike E., dip 10° S. Dolomitic limestone, strike E. and W. Two Miles SSE. of Diamond Drill bore.—Jointed clayslate and claystone, strike E. and W., dip 20° N. One and a Half Miles N. of Diamond D:ill Bore. —Calcareous slate and flags, and dolomitic limestone, strike N.W., dip 35° N. Smith's Well and Neighborhood.—Sandstone and slaty sandstone, strike W. 10° N., dip vertical. Quartzite and quartzose sandstone, strike W.; red and yellow claystone, strike W., dip vertical and north; dolomitie limestone and calcareous grit. Sunday Creek.—Blue calcareous slates and flags. Dolomitic limestone, quartzite, and sandstone, strike Ki. dip almost flat. Limestone slate, red slate, and sandstone; red slate with limestone bands; sandstone and grit on purple kaolinized slate. Old Myrtle Station and Neighborhood.—Dolomitic limestone and calcareous slate, strike N.W., dip S.W. Sandy claystone with streaks of carbonaceous matter in joints and bedding, strike N.W., dip 65° S.W. North of Sunday Creek.—Clay slate and hard massive calcareous claystone, dolomitic limestone, red y mite ee shaly slate and sandstone, strike N.W.; claystone, red slates, and sandstone. Railway Cottages N. of Lyndhurst Siding.—Claystone and soft sandy claystune, red, white, and yellow, in color: strike N. 10° to 15° W., dip 60° E., with many blows and veins of quartz. St. 4’ Beckett's Well.—Sandy claystone under alluvium. Murray's Shaft, and near Lake Weatherstone.— Black slate with seams of iron pyrites; quartzite, sand- stone, clayslate, and kaolinized slate: strike N.W., dip vertical. The above varieties of rock comprise those forming the lowest or bed rocks, and illustrate the kind of rocks which will be found to underlie the shale or coal-bearing formation. The strike or bearing of the strata indicates the direction of the axes of upheaval, which as a general rule vary from E. and W. to N.W. and §.K., although in some instances they are nearly due N. and S. Mesozoic orn SECONDARY Rocks. The secondary rocks, which contain the coal-bearing shales of Leigh’s Creek, appear to occupy deep basins, which haye been eroded in the softer parts of the older rocks, and which at one time formed a chain of lakes of various sizes and irregular shapes, extending northwards towards the region of Lake Eyre. These lake depressions were formed after the upheaval of the primary strata into their present position with regard to one another, although there is evidence that there has been a gradual sinking of the whole of the rocks since the deposition of the shale deposit which now fills these lake depressions. The fossils are of a character indicating vegetable and animal life of a kind which could have existed only in fresh water. To allow of these lakes containing fresh water at that time it was necessary that they should have had outlets to the sea, or to some larger lake further northward, otherwise their waters would have become salt. They must therefore haye been above sea level. At present the depth attained by the diamond drill is 1,800ft., which is over 1,000ft. below sea level. The surface of the country and the surrounding mountain ranges must therefore have been elevated more than 1,000ft., and probably to a much greater height, above the present level. This greater altitude, and consequent increased moisture of the atmosphere, would account for the then different vegetation. The general elevation of the surface of the flat country at Leigh’s Creek, according to the railway measurements, is 777ft., and it falls gradually going northwards, being at Farina—a distance of thirty-five miles—300ft., and at Hergott—a distance of sixty-eight miles—152ft. above sea level. The upper rocks of mesozoic or secondary age at Leigh’s Creek are in descending order :—l1st. Quartzite and sandstone; 2nd, argillaceous sandstone on conylomerate. At the Cutaway Hills, near to the Leigh’s Creek railway station, these rocks form cappings, more or less horizontally disposed on the primary claystones and slates. There are two exposures of- these rocks: the elevation of the higher is about 200ft., and of the lower 170ft. above the plain. They form escarpments on nearly all sides, and the greatest thickness is about 150ft. Fifty feet of this is quartzite, 50ft. sandstone, and the remainder argillaceous sand- stone and pebble conglomerate, chiefly quartz. The thickness of the beds varies greatly, even in the small area covered by them. Both the quartzite and sandstone show impressions or casts of large strap-like leaves of plants, and smaller reed-like markings, which have proved too indefinite for identification by a paleontologist. The rocks are, howeyer, lithologically and in position very similar to those at Mount Babbage and Mount Adams, at which places I found fossil plant remains a few years ago which were examined by Dr. H. Woodward, of the British Museum, who published notes concerning them in the Geological Magazine of July, 1885. The conclusion he arriyed at was that they were probably of the lower cretaceous age. At three or four different places to the southward of the Cutaway Hills, on the plain beneath and in the vicinity of the present bore, there are small outcrops of quartzite and sandstone, which I take to be outlying patches of the same rocks. Resting 3 Resting on the carbonaceous shale, the slates and other primary rocks in horizontal beds, and forming table-hills and table-lands with escarpments, there is a thin but widely-spread formation, composed of boulder gravel and shingle, in some places unconsolidated, at others mixed with soft gypsum and limestone, and again as a hard limestone conglomerate, which covers a large portion of the area. The boulders constituting this deposit consist of quartzite, sandstone, slate, limestone, dolomite, quartz, &e. Underlying this there are often white kaolin and sandstone beds, with gypsum, mottled clays, and ironstone. In some places this boulder drift and conglomerate is replaced by a thin bed of yellow jasper rock and flinty quartzite, which caps the table-hills in the same manner. ‘This rock becomes more common to the northward, towards the end of the main range, where it overlies the gypseous clays, kaolin, and sandstone of the marine cretaceous rocks, or artesian water formation. \ Lricu’s Creek SHALE. This rock formation, which has since proved to be coal-bearing shale, was first found during the excavation of the Government dam, about half a mile 8.W. of Leigh’s Creek railway siding. It outcrops at various places along the course of Leigh’s Creek for some twelve miles north, and has been exposed in wells sunk at various places along that creek. The first basin occupied by the shale formation is that in the neighborhood of the railway siding and township. It is almost entirely surrounded by primary rocks, and has only a narrow outlet to the north. (See map and section.) Its length is about two miles, and the width varies from one aud a half to two miles. At the Government dam carbonaceous shale was found, and in a shaft sunk to the depth of about 70ft., near to the same place, thin seams of coal were passed through. ‘This shaft was abandoned on account of the influx of water. On the western side blue and variegated clays, with ferruginous claystone bands, dip east- wards, at an angle of from 20° to 30° off sandstone and calcareous slates of primary age. These clays zre me wie! outcrops of the carbonaceous shale, and the ferruginous claystones are interstratified with the shale. The second basin les to the northward of that just mentioned, and is much larger than the last described, widening out or narrowing according as it is restricted by the outcrop of the older rocks. (See map and sections.) The bores sunk by the Government are in this basin. There the geology of the shale formation can be best studied by means of the natural outcrops of the rocks, and by the record of the diamond drill bores which have been sunk. The surface of the basin is a plain through which runs Leigh’s Creek, which forms wide flats at a. slightly lower elevation. ‘The surface of the higher plain is strewn with more or less waterworn boulders, gravel, and shingle, which have resulted from the denudation of the limestone conglomerate, which rests horizontally with gypsums and calcareous clays on the superincumbent rocks. ‘These consist of blue clay and shale, interstratified with numerous bands of brown iron ore, clay ironstone, and sandstone, which constitute the outcroping portions of the Leigh’s Creek carbonaceous shale formation. These ferruginous bands are generally very peculiar in position, extending in long, more or less parallel lines, and dipping at various angles from 10° to 15° and 30° to 40° towards the centre of the basin. Twenty or thirty of these paralleled outcrops may be discerned in passing over a few acres of ground. The lines of outcrops are often continuous for a considerable distance; sometimes they thin out to nothing, and at other times their outcrop is marked by a disconnected line of circular ironstone mounds. In structure they are also peculiar, the beds being composed of. large and small irregular lenticulir and globular concentric masses of brown oxide of iron and clay ironstone, having cayities in the centre containing oxide of iron (red and yellow ochre) in a finely divided state. Elsewhere they consist of claystone and clay ironstone, and sometimes, but rarely, of sandstone. In thickness they vary from that of a sheet of paper to two or three feet. In the southern part of the basin they dip at a high angle (85° to 40°) off cleaved clayslates, and strike W.S.W. and E. and W. On the eastern portion along Leigh’s Creek they dip at angles of from 5° to 20°; on the northern portion at angles of 25° to 380° off calcareous flags of limestone. In the southern portion there is what appears to be the outcrop of a coal seam about 3ft. thick, dipping northward towards the diamond drill bore, at an angle of 15° to 20°. This outcrop is much mixed with gypsum and earthy matter, but may be the outcrop of the seam passed through at 1,500ft. in the bore. If it is the same seam, and continues without faults, then there is a thickness of 500ft. of shale below the coal seam to be passed through before the primary rocks will be met with in the bore. The two diamord drill bores haye been sunk in the position shown on the map. No. 1 Bore was sunk to a depth of about 170ft. in the shale, which, with the seams of coal here, dip $.E. and towards No. 2 Bore, at an angle of 10° to 15°. The distance between the bores is about one and a quarter miles. In neither bore have the bands of oxidized iron been met with; but in each numerous bands of fine-grained argillaceous (sometimes calcareous) sandstone haye been passed through at intervals in the shale, which probably represent them. The decomposition of these near the surface has doubtless caused the formation of beds of ~claystone and brown iron ore. On the surface, along the outcrop of iron oxide and clay ironstone, numerous casts of freshwater mussels, composed of oxide of iron, have been found. The same fossil, composed of iron pyrites, has also been found at No. 1 Bore in the shaft since sunk. A cast of what may have been a univalve shell was als» found at the same place. In No. 2 Bore fossils of the same genius, with portions of the shell adhering, have been met with in boring at intervals down to a depth of some 1,700ft. or more Numerous impressions of plants, chiefly ferns, occur in the shale in both bores down to nearly the lowest depth yet reached. Some of these were fairly well preserved, and have been identified by Mr. Etheridge, who has written the accompanying valuable paper on the subject from specimens supplied. by me. Similar leaf remains have also been obtained from the shale in shallow excavations at several other places in the neighborhood. The No. 158. + The shale raised from the bores is found to contain a considerable percentage of carbonaceous and bituminous matter. It varies in color from a light slate to black, and when placed in a fire often emits a considerable quantity of inflammable gas which leaves a solid white ash. When heated in a retort, gas,, water, tar, and oil are produced. The shale when seen at its junction with the primary rocks dips, as previously mentioned, off them towards the centre of the basin unconformably at various angles from 10° and 20° to 40°. Originally it must have been deposited horizontally in the still water of the lake, and the present dip of the beds therefore points to a subsidence of the central portion of the basin, which may have been caused bya sinking of the primary rocks underlying it at the time of the deposition of the formation, or by the shrinking or settling down of the beds through their becoming more consolidated, or through some other change taking place below. In the cores raised there are often evidences of faults or joints in the shale, caused by a fracture of the mass, and the sliding of one side up or down against the other, resulting from such movements of the strata. Faults of this kind doubtless account for some of the numerous parallel outcrops of the ferruginous bands, all dipping in the same direction, which appear in.some parts of the basin. ‘The stratifi- cation of the shale in the No, 2 Bore in its deeper parts is sometimes distinctly horizontal; at others, judging by the layers of leaf impressions, at an angle from 20° to 40°, but as a rule there are no lines of stratification visible. A high percentage of carbonaceous and bituminous matter has been noticed in the shale of No. 2 Bore for a considerable depth, some of the core containing as much as 30 and 40 per cent. An analysis by Mr. Cosmo Newberry, C.M.G., shows that free petroleum also is present in it. This points to the fact of the shale having absorbed petroleum from some source or other, and indicates the probability of petroleum being met with in larger quantities below. Whether it will pay to extract from the shale, oil, tar, and other products deyeloped by heat during the process of distillation is a question which will have to be settled by future experiment under the conditions of cheap fuel and an economical process. Northward of the second shale basin the primary rocks again approach the surface and form islands rising out of the plain, the valley of Leigh’s Creek becoming contracted for some distance, and again widening out into plains in the neighborhood of Lyndhurst Siding, and eastward and westward of that place. Although this is the case, these plains are occupied at intervals by the primary slates, sandstones, quartzites, limestones, &c., which are often observed to form the bases of the flat-topped hills and escarpments of the table-lands, as shown on the map. North of Sunday Creek, near the railway cottages, the shale comes to the surface, as also do the bands of ironstone, and at one place a band of carbonaceous matter with gypsum and brown iron ore, and the out- crop of a coal seam from 1ft. to 2ft. thick, are visible. From the great thickness of the Leigh’s Creek shale formation it is to be expected that it will be found to extend northward towards and under the great central plain. The coal-bearing shale on the eastern side of Lake Eyre may represent the same formation. ‘This point, however, is one which will have to be determired by future fossil evidence. On the Frome, south of Mundowdna Station, and at Attraction Hill, near Hergott, there are ironstone and conglomerate beds which bear a great resemblance to some of the ferruginous bands of the Leigh’s Creek basins, and may be their representatives. What portions of the marine cretaceous series of the great plain to the north is underlaid by these freshwater coal-bearing shales it is impossible to say, until a thorough examination has been made of the country in the neighborhood of the outcrops of primary rocks bounding them, or until bores have been sunk, as suggested in my annual report, 1883, page 11, TERTIARY Rocks. Westward and north-westward of Lyndhurst Siding there is an extensive area of red sandhill country, which overlies all the other rocks. These last, together with the alluvial deposits of the creeks, comprise the tertiary and post-tertiary formations of the district. DIAMOND DRILL BORES. No. 1. Bore. The following is the section :— Surfaceisoily clayiy Gos caectemeienteeiie racers siete ee Be tiiviel eiavels ee x cheslawre irae deleie e's EEO Let) Shalemisensrter domcmosne de anganO oc sapgaoa Wi): 2 See shale interstratified with thin layers ‘of coal and coaly matter ...... 10S “Wa oeasneA cases 7 ie esi sl efalel ela) e\-eje/s1 «'s\o epee Este Tare onengssononenuoogra ee F Carbonaceous'shalemeceraon.ccimateen holes tees ate 7 vlo, SOODODCOO HES 330 GA5300 eo Mesozoic age. Shale’ story iis sues a sree cle ohie ee ele Reehtiers « o.8a.s- oo ae eee tee i) Shale and carbonaceous shale with layers of coal :iericmetos oe tdvie celeste dads vue (pt Shiela Qo de.cuice-coren go tre erete aie tare wet keke: oie 6 Ee ee EC eae 12 170 feet. Kaolinized gritty slate with much mundic resting or inclined beds of calcareous clayslate, quartzite, and limestone . \ Paleozoic age. eee enews Ce | se eee eee eees No. 1 Bore, Analyses of Coal (Mr, Goyder, jun.) Volatile ; Water Depth. Hydro-carbons.| Carbon. “3 at 21°, ; LSOIt. 10 137 Lbemeaes erste Piste sta/shersteteters eltsleleiei sie 33°88 38°48 8-69 18°55 |Averageoffouranalyses Besides 5 Besides this seam of coal, the carbonaceous shale from 125ft. to 135ft. above the seam, and from 137ft. to 142ft. below it, contained thin layers of coal and coaly matter interstratified with it. The coal here resembles lignite and brown coal, and is softer and more easily broken up on drying than that found in No. 2 Bore. This may be due to its proximity to the surface, and the consequent lessened pressure it has undergone. According to the analyses it is a hydrous coal of a similar class to that in No. 2 Bore, so that I see no reason why the two seams may not be connected and be parts of the same bed. The great depth of the basin in comparison with its area, and the fact of the shale beds dipping towards its centre, in my opinion render it probable that the coal beds will be irregular in thickness, and have a cake- like form, attaining the greatest thickness in the deepest ground. Before sinking deep shafts it is necessary that more bores should be put down for the purpose of ascertaining the position of the coal, its depth, the presence or otherwise of faults or breaks, and the proper place for sinking a shaft; there will be no danger of possibly useless expenditure in sinking say 1,500ft. for coal which may be cut at a depth of 500ft. No. 2 Bore. In this bore, from near the surface to a depth of 1,496ft. 8in., the drill passed through shale, with siliceous and calcareous bands, containing a varying percentage of carbonaceous and bituminous matter. At 1,496ft. 8in. a bed of coal was met with, which continued down to 1,544ft. 6in., at which depth the drill again passed into carbonaceous shale. This has continued with occasional thin seams of coal and coal shale (or coal containing a large percentage of ash), to the present depth of 1,800ft. At from 1,764ift. to 1,774ft. the occurrence of this coal and coal shale was most noticeable. The total thickness of the main seam of coal proved to be 47ft. 10in. ANALYSES OF CARBONACEOUS SHALE FROM No. 2 Bore. The Government Assayer (Mr. G. W. Goyder, jun.) reported October 30th, 1890, that the shale from 965ft. when distilled gave 3,000ft. of unpurified gas per ton, a little tarry matter and water, and a trace of petroleum. The following table shows the percentage of carbon and bituminous matter at the various depths :—~ The Government Assayer’s Analyses. Combustible Combustible Nake Depth. Matter. Ash. Moisture. Depth. MAtiCS! Moisture. Feet. Per Cent. Per Cent. Per Cent. Feet. Per Cent. Per Cent. Per Cent. Oi LOLS Fs siegrerdetesys.6 12-00 86°00 2°00 OS Omer kets as eieione 20°72 1-22 2°06 GC LORS4 ee cig aires 6 18°18 80:00 2°00 104 0a. eiakedaiersie« 5 21°55 76°26 2°19 SOL tOLaO? % eis earns ae 20°00 78:00 2°00 TR04omee eee 6 Odio 28°50 71°04 0-46 BDO MERE: che vege nieeale & 19-00 79°00 2°00 TOS Sialeoneste sac ous 20°10- 77-66 2°24 Sod meteteye crcherapaieeuclere ote 20°74 78°35 TO DOG Sees Sfeteterave 20°79 76°94 2°27 OBO ain erie. « Selelatel ails, « 19°57 79°42 1°01 MOOS Reyes crscsts cc. arene 19°04 78°12 2°84 Mr. Newbery’s Analyses. Fixed Carbon. Volatile Matter. Ash. Water at 212°. TR TART OCC Vue ® ayaa rat asia 8°30 11°75 75°45 1-50 Nod TRELOOL ure rereseretarcterstersveteretcls «ce 11°95 14°55 71°80 1°70 1,150 feet to 1,158 feet ...... 8°80 14°15 73°45 3°60 He states that this shale contains a trace of free oil. (Report, Melbourne, November 5th, 1890). The Government Assayer’s Analyses.—continued. Combustible Depth. on beetle Ash. Moisture. Depth. Matter. Ash. Moisture. Feet. Per Cent. Feet. Yer Cent. ABI BoopmobOC On ot 24° 4 == — oo mreneseeiveersiecets si 23°30 _— — GLB Os Veletals aie Ridielersicis © 24° 8 —_ — LOB aseqntia ale ein pelos 27°20 —_ —_— AEZOO Dent eveieitenienes’s 15°09 — — 25 Otter eerste orallcteyetainie 18:00 _ — BOD aortas eiejeetarey)-te0s 31-00 — -- TEZS (ihe se esaee« . 23°80 — — MAL Oi este vis/eloeine So 27°00 _ — W289) 5 010 ccc c reece 20:00 _— —_ Hydro-carbon. Coke. Ash. Mixture. US EAY noeeomgo voc’: mOnmoT 29°50 5°72 62°86 1:92 UGS CCE 5agndbod condo ab0nE 30°90 5°89 61°67 1°54 ANALYSES No. 158. 6 ANALYSES oF Coat Sram, No. 2 Bore. Government Assayer’s Analyses. 4 7 Tater ; Depth from Surface. Pied cuthonet Carbon. Ash. wy ee oe eee L,A9GE. Sin, to, OOLLt-eAin: pits trie HosOoome 32:27, 43°20 3°54 20°91 Average sample 1,509ft., 1,510ft..... i cla tts Sseeocts MERE 34°55 42-14 1°38 21°93 1:61 466... 1 Ol Stty.1. cnet tee Sebi Sone 28-60 36°46 17-08 17°86 Nba Meme eg cacao oaenokoucnes odes 28°30 37°26 13°36 21:08 LiSTSIt Stow O20ite pittance renerecater IG.O0 28°54 42°93 10°46 18:07 L52if, SOUR E . eacre eee meee 27°18 40°54 ie ee LEP RnOS ann men CdOo oO COON Mons ODOR DOoNOr 26°74 44°50 L170 “00 1 S26A0t.. 2st, bs ee eee | 24-88 45-00 10°52 19.60} TWo samples 162 (Lt. debi Olts a eeeiertnte eto stst ner erier 23°83 43°69 16°16 16°32 WRG rhac (ibs TOU Sontonoooece omooas 28°45 45°57 10°70 15°38 1,5294t , ee SeoaGn goec ropes tn Sone VOT 26°88 44°2 12°05 16°83 1,531ft., 1,532ft. PAssdGoans Toanons 26°37 88°56 Dei, 13°30 1,532ft. éin., iE 533tt. ‘Gin, aPepemOishals Rerenceer taker suenaeyc 24°73 42°57 18°93 13°77 1. 30-Gfbc | FAO, Single tee ee 94-51 43°21 14:88 17-40 1,540ft. sin., WOAN Eby LOI tr cera sterner egers 24°68 40°75 16°56 18°01 TATE F ALO me tom, DLO EMO weet ete ot alate 25°98 41°18 13 59 19°30 W544 Ft, LGiah ca sea tenors ciseie stencils, ee hea shiaiiets | 21°53 33°50 81°49 13°48 Bottom of seam The following is the report of Mr. Cosmo Newbery on the samples of coal submitted to him for exami- nation, taken from the core raised from 1,496ft. 8in. to 1,504ft. or thereabouts :— LEIGH'S CREEK COAL. Melbourne, June 10th, 1891. I have the honor to report that I have examined the samples of coal submitted to me by your Govern- ment Geologist (Mr. H. Y. L. Brown), marked Leigh’s Creek. In many of its characteristics this coal differs from the bituminous coals of Great Britain, New South Wales, and Victoria, and in some respects resembles tbe most dense brown coal of Europe. Possibly it is an intermediate body, having some of the characteristics. of both the brown coals and the true bituminous coals. Like a brown coal it is partly soluble in caustic potash, has no tendency to cake, and leaves no cinder after burning. The ash is only from 274 to 3:9 per cent., and is a fine white powder. On the other hand it burns like a true coal, and the products of com- bustion and distillation are those of true coal. The amount of absorbed water—18 to 20 per cent.—is more like the property of a brown coal. None of the true coa's absorb water to this extent. But taking all its characters and properties I think it should be classed as a bituminous coal and not as a brown coal. All the drill cores given to me were made of irregular-shaped fragments of two varieties—one a bright black coal and the other a dull black with a shade of brown, and with a slate or shale like texture. The composition of both was almost identical in the first samples submitted, but in the last the ash in the dull portions rose to 80 per cent. and over, while the bright jet-like parts had not altered. Probably the bore is passing out of the best portion of the seam. ‘The coal does not take the fire easily, but when lighted it burns well, and will be an excellent fuel for steam and domestic purposes ; but owing to the absence of cinder and the small powdery ash it will not be burnt with economy on ordinary firebars, as all the small fragments of unconsumed coal would fall through into the ashpit and be wasted. Mr. J. J. Woolgar, of 104, Queen. street, Melbourne, has designed bars for burning our brown coal, which I think would burn this coal with great economy for either stationary or locomotive engines. Mr. Meekeson, the Inspecting Engineer of our Department of Mines, is now reporting on these bars, and I would suggest that you should obtain a copy of his report. Mr. H. L. Y. Brown saw them in use with brown coal on his recent visit here. I find that the coal when exposed to a perfectly dry atmosphere for less than twenty-four hours loses almost all its absorbed water, and I think it does so without becoming much more friable. This is a very inportant point, and I would suggest that some further tests should be made, as it would of course greatly increase the fuel value if the water can be easily evaporated and the coal not rendered brittle. The water determinations were made at a temperature of 100° C., and are not quite correct where the ash is high, as the kaolin of which it is composed would not give up its combined water at that temperature. The first sample brought by Mr. Brown gave :—Water, 18:80; hydro-carbons, 24°95 ; fixed carbon, 52°90; ash, 3°35=100:00. A portion of the bright jet-like part of the above gaye :— Water and hydro-carbons, 43° 15; fixed carbons, 54°45; ash, 240=100-00. The later samples after the drill had passed through over 2Cft. gave :— Water, 12: 30; dydro-carbons, 17°15; fixed carbon, 41:00; ash, 29°55=100-00. Bright black coal separated from the spore :—Water, 23°20; hydro. carbons, 19°90; fixed carbon, 52°95 ; ash, 3°95=100:00. When exposed to a dry atmosphere the first sample lost its water, and gave a result equal to—Water, nil; hydro-carbons, 30°73; fixed carbon, 65°14; ash, 4:12= 100:00. This represents a fuel of very high value, ‘but further experiments should, as before stated, be carried out to ascertain to what extent the drying renders the coal friable. I have not given the gravity of the coal, for it, of course, varies with the percentage of water and ash. I have, &c., J. COSMO NEWBERY. ANALYSES 7 ANALYSES OF CoAL AND Coat SHALE FROM Various Deprrus, No. 2 Bore. Government Assayer’s Analyses. Depth. Hydro-carbons. Volatile DRC t te SIO i cea s ooh satecnere Gawes Sra aes, - eee ae ee ey Gt Bin ees os eas a ee WASe 1,774ft. 1,7748t. 28°80 19°32 16°57 17°55 23°01 29°03 26°76 28-22 Carbon. Ash. By ee 43°19 10°77 17:24 83°44 38°10 9°14 28°33 46°38 8-72 16°09 58°37 7-99 17°61 62°52 6:86 40°25 19°65 11:07 34°91 97°23 10°10 46°48 2°68 22-62 Coal Coal shale ce “ce ce 6s (a3 Coal These bands of coal and coal shale or impure coal are interstratified with shale, containing more or less carbonaceous matter, and often thin veins or streaks of coal. EXPLANATION OF THE MAP AND SECTIONS. On the map the boundaries of the various formations have been delineated so far as a surface examina- tion will allow, and also the areas occupied by the formations have been colored, so that the area likely to be coal-bearing, or that in which coal-bearing rocks may probably be met with, can be seen. The sections represent the position of the stratification of the country, so far as indicated by the surface rocks and the bores which have been sunk. No. 168. HENRY Y. L. BROWN, Government Geologist. PLANS aE aoe JHORSE igh Ck a ie e u \ hs sf , . / Lg § P.PN°158.1 = dy ped as 3 ; x S MESOZOIC. PALAOZOIC. s CE TTENN RS PADDOCK Nn! SUS ty ee eae ora Yr ame ~ - Bea eee 7 ors r; Nsiat hentai we 4 ~~ d ' { = x — up te a. = Ae - w~ \ Eee 2) Ae ie com ND Von Ps ie — CPND DOCK HUT a. =~ re ¥ % ‘ \ % - wan ie aaah = ’ SG Cae ae ‘ ea ven r f Cn ee = \ LORS 1 Diese Ae oe jt = x A a ie See —T ax —I aN SOUTHS AUSTRALIA. Ue OF THE ‘che ie LEIGHS CREEK DISTRICT, With special reference to the Carboniferous Deposits. Scale —2 Miles to 1 Inch. REFERENCE AND EXPLANATION OF COLORS. TERTIARY AND POST-TERTIARY. = Red sand, loam, and clay of the sandhill country. Sand, clay, and gravel of the creeks and gullies, La CRETACEOUS Calcareous conglomerate, clays, marls, gypsum, sandstone, conglomerate, kaolin, ironstone, quartzite, and jasper rock of the table land and stony downs. OOLITIC. | Coal-bearing shale (Leigh's Creek shale formation.) LOWER SILURIAN OR CAMBAIAN. Clay and calcareous slates and flags, quartzites, sandstones, grits, limestones, dolomites, and conglomerates, | Henry ¥L Brown.| Government Geologist, 9% September ISI. To. ie se Mca Be) Open plan 2 Bush & herbage = Red sandy loam, 24678 a COVT DAM "DRY WELL Ro aN, Vv ) Low bushy ruses Blue & saltbush / LENS GUMS EH. i 2 4 \ XY ‘ Si ae ut WHEE Sy) , STN AHF Aine Een ( ae WELL, ye. =< Oy Je a4 <*PRDDOC KY Swim oy CREEK. PADDOCK + 1) if iy a eee ' : SS ee w WINDY CREEK DAM ry =~ £é ( i, f | = e : Ss i ) SURVEYOR GENERALS OFFICE. ADELAIDE. A Vaughan. Photolithographer (310), ‘—— re low ee: overt Uy Co ATG, Co Ute, Se = E You ate \ SLOWER WELL — P.PNO/58.) South. Windy Creek. Section from Farina to ntal and Vertical)—S280ft, Henry ¥ L Brown, Government Geologist, 9% September 1891. West of Lyndhurst Railway Siding. \ ! caves 4 ' SURVEYOR CENERALS OFFICE ADELAIDE. A Vexughan, Photo lethograg yer (312 2) St. A’ Beckett s Water Flole. t A- Diamond Drill, Bore No. 2. i) *. ee & General Section from Farina to Windy Creek, SCALE (Horizontal ana Vertical)—8280ft, to lin. (lin. =1 mile.) PP N® 1582. Government Dam. Leigh's Ck. Railway Stn. a Sa Henry ¥ I, Brown, Government Geologist, 9 September ISI. Windy Creek. South. Diamond Drill} Bore No. a SCALE (Horizontal Lhamond Drit Bore No 2. Government Leigh's Ch. Rail Section through SCALE (Horizontal South-West. Henry YI Brown, Government Geologist, 9 September 1891. Diamond Drill, | Bore No. ae Leigh's Creek. . Leigh's Creek ‘ Flats. Suggested site Coal outcrop. _ for bore. ‘ —— ~ ete. a) —— Sea Level. Probable position of coal seam. SS 1800/4. : 5 aS Probable position of primary rocks BS Se Section through No. 2 Bore, from North to South. % SCALE (Horizontal and Vertical)—1320ft. to lin. (4in. = 1 mile.) Diamond Driil, : . South-West. North-East. Bore No. Te I d as Lhamond Drill. I Suggested site Suggested site Bore No 2. Suggested site Sor bore. Jor bore. Jor bore. Coal Bed, ee 1800/7, See —y Xe Weer. oe a . SSS a ae ee A ee eee Section through No. 1 and No. 2 Bore, N.E. to S.W. SCALE (Horizontal and Vertical)—1820ft. to lin. (4in, = 1 mile.) Government Dam. North-West. reavagaete Leigh's Ck. Railway Stn. Cutaway Frlls, South-West. ; Henry YL Brown, Section through Government Dam and Cutaway Hills. Caer Geologist. 9” September ISI. SCALE (Horizontal and Vertical)—1820ft. to tin. (4in, =1 mile.) L SURVEYOR GENERALS OFFICE. ADELAIDE A Vireedhirn. Photo lichogmupher (312 3) PP N® 1583. South. DESCRIPTION OF SOME SOUTH AUSTRALIAN SILURIAN AND MESOZOIC FOSSILS, sy R. ETHERIDGE, Jun., Patwonrotocist anpd LiBrarrAN, GroLocicAL SURVEY OF New Sourn Wates, AND PALmonrToLocist To THE AusTRALIaN Museum, SypDNnEY. I.—INTRODUCTION. The fossils about to be described were forwarded to me by Mr. H. Y. L. Brown, Government Geologist of South Australia, for determination. Two of the species I believe indicate Silurian rocks; two others Lower Mesozoic ; whilst the last, a Unio, presents greater difficulties in arriving at its possible age. The Silurian fossils were obtained by Mr. Brown in the Levi Range, and between the Finke and Hugh Rivers during recent geological explorations, and will assist in fixing the probable age of another large area of Primary rocks in Central Australia. The fossils referred to the Lower Mesozoic are plants, and were found on splitting-up portions of the Leigh’s Creek bore core. The Leigh’s Creek deposit was first reported on by the Government Geologist im February, 1889, who expressed the opinion ‘* That the shales were probably of Cretaceous age, and that there were good grounds for assuming the presence of coal in them.” ‘Two bores have in consequence been sunk ; one near the 379th milepost on the Great Northern railway, and the other a little south-west of the first. ‘The latter bottomed on Primary rocks, at a depth of 170ft., after passing through a seam of lignite, but no coal. The second bore has been continued to a much greater depth in the Leigh’s Creek formation, with the gratifying result that Mr. Brown’s assumption has proved a certainty. It is from this bore that the fossil plants come. The remainder of the fossils, a species of Unio, are from the Black Hills, north of Leigh’s Creek Railway Station, and from beds interstratified with the shale formation. I had, previously to Mr. Brown’s collection coming into my hands, received from Professor Rk. Tate specimens of the same shell; and as these are also labelled Leigh’s Creek, and are similar in appearance, I have assumed them to be from the same deposit as Mr. Brown’s. II.-—DESCRIPTION OF THE SPECIES. A.—SILURIAN. Genus Rapuistoma, Hall, 1847. (Pal. N. York, 1., p. 28.) RaruistomMa Brown, sp. nov., Figs. 1, 2, and 3. Sp. Char.—Shell depressed, conoidal-lenticular, of five whorls; spire depressed-conate, short ; whorls slightly convex. The last one more flattened than the others, but its ventral surface slightly ventricose, and the periphery very sharp and angular; umbilicus round, its edge sub-rounded. Peristome sub-triangular, almost deltoid; anterior margin of the outer lip horizontal, lower margin oblique; inner or pillar-lip vertical. Sculpture not preserved. Obs.—The genus Raphistoma comprises depressed-turbinate, or slightly conoidal, more or less lenticular shells, with a close suture, a moderately large umbilicus, and a generally sub-triangular aperture. The sculpture strize are suddenly bent backwards along the keeled periphery, leaving a slight notch in the edge of the aperture. These shells possess characters in common with both the Huwomphalide and Pleurotomartide the notch being somewhat similar to the oval emargination of the former and the slit of the latter, but there is no band. It is very probable, therefore, that Haphistoma should be referred to the first of these two familes rather than the second, in which itis placed by Dr. P. Fischer. (1) ‘The latter author gives R. angulatum, Hall, as the type of the genus. ‘This is an error, the first species described by Hall being R. striata, which thus becomes the type. Mr. KE. W. Tryon, jun., determined to be correct, places (2) Raphistoma as a sub-genus of two genera, first under Straparolius (Huomphalus), and secondly under Scalites. He. however, selects the correct type, &. striata, under his first reference. It is obviously necessary to compare our new species with as many of the accepted forms as possible, for stratigraphical reasons. R. Brownai certainly seems to approach R. stamineum, Hall (3), but is higher in the spire, less ventricose below, and with more distinctive whorls. This species occurs in the Chazy Group, the equivalent of the Tremadoc aad Llandeilo of British geologists. It is also near A. lupicida, Salter (4), and R. apertum, Salter (5), but is more ventricose below than the former, whilst the outline of the peristome in both differs from that of R. Brownz in that the pillar-lip of the Australian shell is much more vertical, whilst from the second Canadian species, by possessing a higher spire. Both the Canadian shells are from the 1. Man. Conchyl. et de Pal. Conchyl., 1887, p. 851. 2. Struct. Syst. Conchol., 1883, 11., pp. 219 and 223. 3. Pal. New York, 1847, 1., p. 29, t. 6, f. 4-5a. 4. Canadian Organic Remains, Dec. 1, 1859, t. 2, f. 1-3. 5. Ibid, f. 4. Black River and Trenton Groups. (Llandeilo in Great Britain, and Etage D in Bohemia.) Again, our fossil is very close to #. lenticularis, kmmons (1), of the Trenton Group, more so perhaps than to any other species, but the whorls are less convex. I[t is distinct from Raphistoma labratum, Emmons (2), on account of the depressed spire of the latter, a fossil of the Calciferous-sand rock of the American sequence. Two other species from the same horizon, R. rotuliformis, Meek (3), and #. trochiscus, Meek (4), are equally dis- tinct, the remarkable open umbilicus,in which all the whorls are exposed, separating both species from R. Brown. Messrs. Hall and Whitfield have described a Raphistoma from the Chazy Group under the name of /. acutum (5), which differs by the greater depth of the body whorl and a greater ventricosity. One of the largest species of the genus, if not the largest, is R. niagarensis, Whitfield (6), from which k. Brownz differs in the form of the peristome, and a smaller umbilicus in proportion to its size. To 2. Nasoni, Whitfield (7), our species again approaches closely, both in size and height of the spire, but the latter is too high to be confounded with that of the Australian shell. It is, however, almost as closely allied to this Trenton species as to R. lenticularis, Emmons, previously mentioned. 1. Geol. New York, 1842, Pt. 2, p. 393, f. 102 (2-3). 2. Loe. cit., p. 312, f. 84 (2). 3. King’s U.S. Geol. Explor. 40th Rar, at:, 187, HV: bts i4°p.19, t.1,\f. 2-2b: 4. Loc. cit., t. 1, f. 8-8b. Bs Loc eit., Pt; 2, p. -235,.t. 1, £20-22. 6. Geol. Wisconsin, Survey 1873-79, 1882, 1v., p. 295, t. 18, f. 10 and 11. 7. Loe. cit., p. 215, t. 6, f. 2 and 3. With B—No. 158. 10 With the British species it is somewhat difficult to make a comparison, from the very poor figures and descriptions of them so far published. Raphistoma equalis, Salter (1), from the Caradoc seems, from the single figure known to me, to be too much depressed to’ be identical with our species. The figure of R. ellipticus, Portlock, sp. (2), from the Caradoc and Upper Llandovery, represents a distorted shell, otherwise it would probably resemble the Australian species. Lastly R. lenticularis, Sby. (3) (non Emmons), is a very much compressed form and truly lenticular in shape, and therefore cannot be closely related to R. Brownit. After a careful consideration of the various species reviewed, 1 think the two American shelis previously mentioned, R. lenticularrs, Emmons, and R. Nasoni, Whitfield, are the nearest allies of R. Brown. Both are Trenton species, or referable to the Llandeilo of British geologists, and Etage D of the Bohemian sequence. Locality —Storm Creek,-Levi Range, near Tempe Downs, Central Australia. 1. Zuomphalus qualteriatus, Salter, Mem. Geol. Survey Gt. Brit., 1848, m., Pt. 1, t. 14, f. 7. 2. Geol. Report on London- derry, &e. 3. Murchison’s Siluria, 4th Edit., 1867, t. 10, f. 10. Genus OrrHocERAs, Breynius, 1732. (Dissert. de Polythal., pp. 12 and 28.) OrTHOCERAS, sp. ind., Fig. 4. Obs.—The works of reference at my disposal are quite inadequate to enable me to determine this species, although, so far as my investigations have gone, no species exactly like it has been met with. From its association with the Raphistoma it is Basbobly. a Lower Silurian form, but in some points indicating an Upper Silurian facies. Our specimen resembles Crthoceras phones Hall (1), of the Clinton, or Upper Llandovery Group, but the siphuncle of the species named is slightly eccentric. Again, it is not unlike, O. saturn?, Barrande (2), characteristic of Etage D and F (Llandovery and Ludlow), but the structure of the siphuncle ‘again separates the two. The portion preserved is four inches long, three quarters of an inch at the distal extremity and one and a half inches at the proximal end. On subtending the apical angle the shell from the fractured proximal end to the apex would measure eleven inches in length. The width of the septa as exposed on the sides is less than one-eighth of an inch, the edges gently waved, and the septal surfaces moderately convex, with a central siphon. The section of the shell is a wide oval. 1. Pal. N. York, 1&52, i1., p. 104, t. 31, f. 4a and b. 2. Syst. Sil. Bohéme, 1874, 11., pt. 3, p. 601, t. 255 and 264. Locality.—Between Finke and Hugh Rivers, going from Owen’s Springs to Boggy Waterhole, Central Australia. B.—MeEsozoic. Genus THINNFELDIA, Ettingshausen, 1852, (Abh. K. K. Geol. Reichsanstalt, 1., Abth. 3, p. 2.) HINNFELDIA ODONTOPTEROIDES, Morris, sp., Figs. 1 and 2. Pecopteris odontopteroides, Morris, Strzelecki’s Phys. Descrip. N.S. Wales, &c., 1845, p. 249, t- 6, f. 2-4. Thinnfeldia odontopteroides, Feistmantel, Pal. and Mes. Plants, E. Austr. and Tas. (Mem. Geol. Survey New South Wales, Pal. No. 3), 1890, p. 101, t. 23-25, t. 26, f. 1 and 2, t. 28, f. 8, t. 29, f. 1-5 (for full synonomy /. Obs.—The Leigh’s Creek bore at present in progress has yielded several specimens of this characteristic Australian Lower Mesozoic plant. The discovery of this and the succeeding species may be looked upon as a very important one in South Australian geology, for I am not aware that Mesozoic plants have been before recorded from the Province, with the exception of some obscure Cycadian remains and a problematical Salisburia, described (1) by Dr. H. Woodward, from Mount Babbage and the Cutaway Hills, Leigh’s Creek. The specimens exposed on the fractured surfaces of the bore core are that variety of 7. odontopterotdes with 1. Geol. Mag., 1885, 11. (2), p. 289. strictly rhomboidal pinnules, and close set, or in fact, almost semi-imbricating, but not as large as the largest usually found in Eastern Australia, although equal in size to some there met with. ; In general features the specimens correspond both with rhomboidally obtusely-pinnuled examples from the Hawkesbury Sandstone, at Dubbo, in New South Wales, figured by Milne Curran (1), and the Ipswich Basin, in Queensland, by Carruthers (2); and it is even possible they may fall into the var. obtusifolia, Johnston (3), of the Spring Hill Shales of Tasmania. Locality.—Leigh’s Creek Bore, No. 2, Leigh’s Creek, South Australia, at depths of 240ft., 622ft., and iL stb. 1. Proc. Linn. Soc. N. 8. Wales, 1884, rx, Pt. 2, p. 252, t. 9,f.4. 2. Quart. Journ. Geol. Soc., 1872, xxvut., t. 27, f. 2. 3. Syst. Ace. Gea. Tasmania, 1888, t. 25, f. 7, 9, and 14. Genus MacrormnroPtERis, Schimper, 1869. (Traité Pal. Veg. 1., p. 610.) MAcROTANIOPTERIS WIANAMATI®, Feistmantel, Fig. 3. M. wianamatte, Feistmantel, Pal. and Mes. Plants, E. Austr. and Tas. (Mem. Geol. Survey New South Wales, Pal. No. 3), 1890, p. 116 (for synonomy/, t. 27, f. 1 and 2. Obs.—A single large example is present in one of the pieces of core. It is a portion of a leaflet five inches in length and two and a half in width, and more or less very broadly strap-shaped, or even obtusely lanceolate. ‘The margins were apparently entire, and are both visible at one portion of the specimen. The veins bifurcate irregularly as regards position, either immediately contiguous to the mid-rib, or near the middle 11 middle, half way between the latter and the margin, or again comparatively close to the last named. Some of the veins remain simple, and the angle of divergence of all of them from the mid-rib is low, but hardly a right angle. I believe this plant to be Feistmantel’s MZ. wianamatte, but as his description and figures differ somewhat, an element of doubt is imparted to the matter. If the outline of the leaflet given by Feistmantel in his Pl. 27, Fig. 1, of the work quoted above, is to be relied on, as that of this species, and it is sup- ported by that of an independent figure (1), then the present plant can hardly be M. wianamatte. On the 1. Wilkinson, Ann. Report Depart. Mines N.S. Wales for 1879 (1880), t. d. other hand Pl. 27, Fig. 2, of the same author accords much better with our specimen, both in form and veination. Feistmantel described the veins as ‘ dichotomous towards the margin,”’ but in both his figures the veination is precisely similar to the description here given of that in the specimen from the Leigh’s Creek bore. Under these circumstances I prefer to provisionally regard the last-named plant as Macroteniopteris wianamatie. M. wianamatte is a typical fossil of the Hawkesbury-Wianamatta Series of New South Wales, and so far as I am aware, has not been met with outside the limits of the formation in that Colony. But in the Ipswich Series of Queensland, a very large Macroteniopteris occurs, specimens of which have been forwarded to me by Mr. R. L. Jack, Government Geologist of Queensland. This, I believe, is identical with the Indian M. crassinervis, Feistm. (1), and although distinguished by the coarsness of its veins, and their distance apart, closely agrees with the leaf from South Australia in general outline. It may be accepted, therefore. that these Mesozoic beds of South Australia contain a Macroteniopteris probably identical with JZ. wianamatta, Feist. Locality —Leigh’s Creek Bore, Leigh’s Creek, South Australia, at a depth of 240ft.-248ft. 1. Pal. Indica, Gondwana Flora, 1877, 1., Pt. 2, p. 102 (50), t. 38, f. 1-3. Genus Unto, Retzius, 1788. (Dissertatio Hist. Nat., p. 16.) Unto, sp. ind. Obs.—A single and somewhat distorted example of a small Unio occurs in one of the pieces of bore core, taken from a depth of 622ft. It is impossible to describe it, or indicate its relationship to described species with any attempt at certainty. It is, however, the remains of a shell about two inches in length, the dorsal margin crushed down and too firmly attached to the matrix to permit of inspection. t With the exception of McCoy’s Unio Dacombii (1), Mesozoic species of Unio have not, so far, been described from rocks higher than the Hawkesbury-Wianamatta Series of New South Wales. From Queensland, however, I am acquainted with four undescribed species—two from the Ipswich Coalfield, and two from the Rolling Downs Formation (Cretaceous.) One of the former, from the Bremer Basin coal shaft, at a depth of 200ft., is of the same general facies as the species occurring in the Leigh’s Creek Bore, but beyond this I am unable to compare them from the ill-preserved state of the latter. The second of the Ipswich Unios from the Bundamba Mine has appeared in lists as U. gregorianus, Eth. fil. MS.. (2), and differs wholly by its size, &c., from that now under discussion. Those from the Rolling Downs Formation 1. Selwyn, Victorian Exhibition Essays, 1861, p. 186; Smyth, Progress Report, Geol. Survey, Vict., 1874, 1, pp. 24 and 35. 2. Col. and Indian Exhib. London, 1886, Cat. Exhibits, Queensland Court, 1886, p. 165. are at present specifically unnamed, but were obtained by Mr. R. L. Jack during the exploratory surveys for the Queensland Transcontinental Railway Survey, under General Fielding in 1881-2. One is from the Government Well at Winton, the other from Sheppard’s Well at the same place (1). The shells are specifically distinct from one another, from the two Ipswich species, and that found at a depth of 622ft. in the Leigh’s Creek Bore. At the same time the latter, the Unio from the Bremer Basin coal shaft, and that found in the Government Well at Winton, are transversely elongated species, as against the shell from Sheppard’s Well, which is a shorter and more obtuse Unio. Whatever comparison can be made is in favour of a relationship between the Leigh’s Creek Bore species and that from the Bremer Basin. Locality.—Leigh’s Creek Bore, No. 2, Leigh’s Creek, South Australia, at a depth of 622ft. 1. Handbook of Queensland Geology (Col. and Indian Exhib., London, 1886.—Queensland: Its Resources and Institutions. Essays), p. 74. Unto Eyrensts. Jate, Figs. 1, 2, and 3. Unio Eyrensis, Tate. Sp. Char.—Shell elongately or transversely nasute, or triangularly wedge-shaped, decreasing rapidly in convexity towards the posterior end; umbonal region fairly gibbous and convex, but the flanks decreasing rapidly towards the ventral margin, within the cast a more or less pronounced sulcus extending from behind the umbones to near the centre of the ventral margin. Hinge line straight, ventral margin rounded, passing rather sharply upwards into the anterior and posterior margins. Anterior end small, somewhat acutely curved, posterior end narrow, obtusely pointed. Umbones eroded; ligament, long, large, and strong; cardinal teeth large; lateral teeth strong, diverging downwards from the hinge line, or dorsal margin. Anterior adductor impressions obliquely conical, but not superficially large, vertically striated, and bounded posteriorly by-a strong subdentate ridge; supplementary anterior scars not visible; posterior adductor impressions feeble. Sculpture of coarse irregularly concentric lines. Length (average) 3}in., height 3,"in. Obs.—I have been favoured both by Professor R. Tate and Mr. Brown with several examples of the internal casts of this Unio in concretionery ironstone from Leigh’s Creek, Great Northern Railway. In all the specimens there is evidence that the umbones were much eroded, and the surface in one or two was covered by a coarsely lined “ epitheca.’”’. The hinge teeth appear to have been of the usual characters, a large cardinal in each valve interlocking, and now represented by casts; and long lateral teeth indicated by slits along the impression of the hinge line possessing a slight oblique downward trend. The anterior muscular impressions are very characteristic, apparently deep and conical, although not superficially large, but bounded posteriorly by ridges, as evinced by deep depressions on the casts. Little No, 158, 12 Little more can be said of these Mesozoic Unios, except that they are quite unlike any of the recent Australian species, being evidently much more substantial shells. In the presence of the partitions behind the anterior muscular sears our fossils correspond to a certain extent with some of the more ponderous. American species. Unio Dacombii, McCoy, from the Lower Mesozoic rocks of the Wannon Coalfield, Victoria, never having been described, it is impossible to institute a comparison between it and our present fossils. With the smaller Ipswich Coalfield species and those from the Rolling Downs Formation there exists no resemblance, but U. gregorianus, Mihi. M.S. and U. eyrensis have many points in common, and it is even possible they may be identical. U. gregorianus was obtained from brick clay overhanging a seam of coal, at Bundamba. U. eyrensis, Prof. Tate writes me, ‘is in all probability Cretaceous; the locality of it is in close proximity to plant-bearing sandstones.” Mr. Brown has been kind enough to forward me a sketch map and section of the Leigh’s Creek Basin, showing the position of the Unio beds in relation to the blue shales, through which the bores have passed This relation will be referred to later ; ; suffice it to say now that at the Black Hills, Leigh’s Creek, the bed rock, Paleeozoic, and probably Cambrian or Silurian, and of -highly inclined clay and calcareous slates, is overlain unconformably by ferruginous outcrops, consisting of ironstone bands interstrati- fied with clay and gypsum. The Unios are met with in these bands, which are at times very thin and composed of only a layer of lenticular shaped bodies, made up of various concentric coats of sand and iron ore (1). Locality.—Black Hills, near Leigh’s Creek Railway Station, Great Northern Railway, Central Australia. 1. H. Y. L. Brown, ‘‘ MS. Notes.” iz. GxrotogicaAL DEepucTIions. Mr. Brown informs me that no cne has published any account of the geology of Levi Range, &c., whence the Silurian fossils come. The material at present available on which an opinion can be based is: certainly not large, but the presence of so distinctive a shell as Raphistoma brings the question within reason- able limits. We have previously seen that this genus extends from the Llandeilo to the Wenlock, but seems to be eminently characteristic of rocks oscillating between the Llandeilo and Llandovery. I do not think it possible, on the evidence, to form a more definite opinion. The age of the blue mudstones passed through in the second Leigh Creek bore is, on the other hand, much more easily determined. We observe that in this bore, between the depths of 240ft. and 1171ft., or through a thickness of 931ft., we have occuring at intervals Thinnfeldia odontopterordes, and at one point a Macroteniopteris. Now, the first of these plants i is, without exception, one of the most characteristic of our Mesozoic coal plants in Australia and ‘Tasmania, and equal in this respect to Alethopteris australis, Morris. It occurs throughout the great Clarence Series of New South Wales (including the Hawksbury Sandstone, Wianamatta Shales, Clarence beds, and Narrabeen Shales), and although payably workable coal seams have not been met with throughout the rock, our plant does accompany such in the equivalent coal basin at Ipswich in Queensland. Here Thinnfeldia odontopteroides occurs 70ft. below the New Chum upper seam at Bundamba, and in the Bundamba upper seam. Similarly Macroteniopteris wianamatte is very characteristic of the Clarence Series of New South Wales, and although I am not aware that this plant has been authentically identified (1) from the Ipswich basin, its place is taken by a finer species of the same genus Macroteniopteris crassinervis, Feistmantel (?) Now these are important facts, not made any the less by the occurrence of a small Unio in the Leigh Creek Bore, No. 2, which certainly bears strong relations to one in the Ipswich beds from the Bremer Basin coal shaft. So struck was I with these facts, and the probability of the beds composing the Leigh Creek Basin being the equivalents of those of the Ipswich Coalfield, that I wrote to Mr. Brown calling his attention to the fact. Since then bituminous coal has been struck in the No. 2 Bore at Leigh’s Creek, which corroborates this view, as indicating that the fuel is not of a “ brown coal”’ or Tertiary age. That it is not Paleozoic is clearly demonstrated by the entire absence of fossils of that age. 1. The late Rev. J. E. T. Woods recognised what he believed might be this plant from Ipswich, but his remarks were made tentatively (Proc. Linn. Soc. N.S. Wales for 1883 (1884), vut., p. 118). We now come to a consideration of the possible age of Unio eyrensis, Tate. The sketch maps and sections kindly forwarded by Mr. Brown show that the Leigh’s Creek shale formation lies in a basin sur- rounded by Paleozoic rocks. In the south-east corner are the Black Hills, whence the specimens—at any’ rate those forwarded by Mr. Brown—are derived. The shells occur in ironstone bands in clay out-cropping at that locality, and forming an integral portion of the Leigh’s Creek shale formation, and this tends strongly to confirm the view entertained of the probable age of these beds, for Unio eyrensis closely resembles the one from the Ipswich Coal-measures named in M.S. by me Unio gregorianus. ‘This is supported by negative evidence to this extent: that so far as the Writer’s knowledge extends, no Unio of this type has been found in the Queensland ‘“ Rolling Downs” Formation, into which the Ipswich Coal-measures insensibly pass. On this point Mr. R. L. Jack remarks, “ To draw a definite line between the Ipswich and the ‘ Rolling Downs’ beds is quite impracticable. The appearance of belemnites and ammonites generally marks the transition.” (1) 1. Handb. Q’land. Geology, 1886, p. 65. It must, however, be understood that the state of preservation of both the Queensland and South Australian Unios does not permit one to assert that the species are identical; but the probability, taking all the sur- rounding facts into consideration, is that they are, and that in consequence the relative ages of the Leigh’s Creek and Ipswich Coal-measures are drawn still closer. Nore sy H. Y. &. Brown. With regard to the Silurian fossils described, the age of which has been determined in Mr. Etheridge’s valuable Report, I may state that some of them were found during my visit to Tempe Downs in September of last year, during a journey with Mr. Thornton, the manager of the Tempe Downs Station, round the George Gill and Levi Range, and also at other places between the Finke River and that place. Since that time Mr. Thornton has kindly forwarded me additional fossils procured by him from Peterman Creek and the head of the Walker and Mariana Bluff, also from Ilpila Spring, Park’s Pass and Henbury; these last Mr. Etheridge has not yet had an opportunity of examining. Lying unconformably on the crystalline metamorphic, gneissic, »and granitic archeean rocks of the Macdonnell Ranges, there are two other rock systems unconformable to each other. The 13 The lower of these consists of quartzite, quartzite conglomerate, dolomitic limestone, limestone, sand- stone, and slate, striking E. and W. On the flanks of the Macdonnell they dip off, and also vertically, towards the granitic and metamorphic rocks. Southwards in descending the Finke they appear at intervals as highly inclined beds, the out-cropping edges of synclinal troughs in which rest the upper system. They are lithologically similar, and doubtless of the same age as the quartzite, dolomitic limestone, limestone, sand- stone, and slate series of the Flinders and other ranges in the northern part of South Australia proper (in the limestone of which fossils of Cambrian age have been identified by Mr. Etheridge.—Transactions Royal Society of S.A., 1890), the Dennison and Peake, Mount Dutton, and ranges to the west of the Musgrave, and in the neighborhood of Mount Burrel in the same district as that under notice. The upper system consists of red and pale sandstone, quartzite, and shale, with thin bands of limestone, also striking E. and W., and horizontal or undulating over large areas, although sometimes where disturbed, tilted into synclinal and anticlinals, with dip of from 15° to 20° to 45° to 60°. It is in these beds that the fossils described by Mr. Etheridge were found. The George Gill, Levi, and James Ranges are composed of these rocks, and they doubtless extend east and west over a large extent of country. EXPLANATION OF FIGURES. PLATE I. RaPHIsToMA BROWNII, sp. nov. Figure 1. Shell seen from the front, showing peristome. Figure 2. Same seen from above. Figure 3. Same seen from below, showing the umbilicus, &e. ORTHOCERAS, sp. Figure 4. Shell seen from the side. ORTHIS LEVIENSIS, sp. nov. Figure 5. Exterior of the ventral valve. Figure 6. Exterior of the dorsal valve. Figure 7. Interior of the dorsal valve. PLATE Ii. THINNFELDIA ODONTOPTEROIDES, Morris sp. Figures 1 and 2. Small portions of fronds showing the characteristic form of some of the pinnules and their venation. MAcROTZNIOPTERIS WIANAMATT, Feistmantel (2?) Figure 3. Portion of a large frond, showing the venation furcate at various points between the midrib and the margin. PLATE III. Unio ryRENSIS, Tate. Figure 1. Internal cast of the left valve. Figure 2. Internal cast of both valves seen from above. Figure 5. Internal cast of both valves seen from in front. On THE OccURRENCE oF AN Orthis, ALLIED To O. Actonie, J. DE C. SBy., anp O. flabellulum, J. pE C. Ssy., In THE LowER SituRIAN Rocks oF CENTRAL AUSTRALIA. By R. ErHeripeGr, JuN., ETC. The present species is an interesting addition to the Lower Silurian fossils already described from the Levi Range, and like those was forwarded to me for identification by Mr. H. Y. L. Brown. The general facies of the shell, which it is proposed to designate Orthis leviensis, is strictly that of a Lower Silurian form, medium size, more or less semicircular form, few and very coarse, wide apart ribs, with the intermediate valleys occupied by a single secondary rib. These are distinctly the characters, not only of the present shell, but also of the species mentioned in the title above, two of the most definitely Lower Silurian Orthis in the British rocks of the age in question. Orthis leviensis is distinguished from O. flabellulum by its much squarer and deeper outline ; by the fact that the ribs are not only much less in number, but are distinct and separate, with interspaces or valleys between much wider than themselves, rather than arched ribs, as in the British species. Furthermore, there is no trace in our shell of the frontal border so frequently seen in O. flabellulum, caused by a regular close and defined, although short, bifurcation of each rib, and circumscribed by a. concentric groove, from the remainder of each valve. These points are exceedingly well shown in the figures of both Mr. J. W. Salter (1), and Dr. T. Davidson (2). Orthis Actonie is very closely allied to O. leviensis, particularly the Welsh forms figured by Mr. Salter (8), in which the valves are deeper, the ribs round and cord-like, with interpolated riblets, which either remain distinct or are furcate from the main ribs high up on the valves. On the other hand, the dorsal valve of O. leviensis is decidedly concave, becoming flattened towards the margins, whilst in O. flabellulum it is uni- formly convex. A certain resemblance is also apparent between our species and O. calligramma, Dalman (4), in which a similar distribution of the ribs is noticeable, but there does not appear to be intermediate or secondary ribs, and the dorsal valve, with the exception of a depression towards the front, is certainly convex. The following is the specific description of O. leviensis. 1. Mem. Geol. Survey Gt. Brit., 1881, 111., 2nd Edit., t. 21, f. 9-16. 2. Mon. Brit, Sil. Brachiopoda, Part v11., No. 4, 1871, t. 34, f. 1-12a. 3. Loe. cit., t. 21, £. 1-8. 4. Davidson, Joc. cit., Part vir., t. 35, f. 1-24. OrTHIS C—No 168. 14 ORTHIS LEVIENSIS, sp. nov., Figs. 5, 6, and 7. Sp. Char.—Shell semicircular—deltoid, wider than long ; valves concavo-convex ; hinge line or cardinal margin longer than the body of the valves; cardinal angles extended into short mucronate wings. Ventral valve slightly convex, but without sinus. Dorsal valve convex at the umbone, concave around it, and flattened at the margins and cardinal angles; umbo sharp and pointed ; area narrow. Surface of both valves bearing strong, prominent, angular, widely separated radiating cost or ribs, variable in number, but never very numerous; secondary interpolated ribs much smaller than the primary, which latter die off on the surface and the valve upwards, or unite with the primary ribs at about one-third the length of the shell from the front margin ; valleys or interspaces flat. Obs.—In the interior of the dorsal valve the cardinal process and brachial processes are slight, but the dental sockets are wide and shallow, whilst the quadrupling of the adductor muscle impressions is not clearly perceptible. In addition to the British species already mentioned, O. leviensis is to some extent related to two American forms, Orthis pectinella, Conrad, and O. subquadrata. The first is well figured by Hall (1) from the Trenton Group, and possesses ribs arranged in a similar manner to those of O. leviensis, but the valves lack the peculiar curvature seen in the Australian species: On the other hand, O. subguadrata (2) resembles O. leviensis in the outline of the shell, but differs from it in the sculpture. (1). Pal. New York, 1847, 1., p. 128, t. 82, f. 10. (2). Pal. New York, 1847, 1., p. 126, t. 32a, f. 1. PLATES Plate LI. SURVEYOR GENERALS OFFICE ADELAIDE, .\ Vieceghatn. Photo lithogrepher (403) PP N® (58.1. Plate II. 158.2 PP NO SURVEYOR CENERACS OFFICE ADELAIDE -| baughan, Mhotodthographer (403) Plate IIL. SURVEYOR GENERALS OFFICE ADELAIDE. A Vircighan. Photolithographer (403) PP N° 158. we w ‘? RAED emir ened _