96. Cambrian Faunas in South Australia with a Brief Note on the History of the Nullagine Basin*

484 [Vol. 18,

96. Cambrian Faunas in South Australia with a Brief Note on the History of the Nullagine Basin*. By Teiichi KoBAYA8rn**. (Comm.by T. KATo,M.Y.A., Oct. 12, 1942.) Parara limestone of the Yorke's Peninsula :-In South Australia the Cambrian strata are exposed as patches aligned in submeridional parallels. In the Yorke's peninsula a formation composed of archaeocyathid limestone above and dolomitic limestone below overlies the Pre-Cambrian basement with a thin sandstone bed at its base, while in many other places it is underlain by a thick purple slate series con- formably and this in turn by the Proterozoic Adelaide series with the Brighton limestone at the top, disconformably. The slate series measures 1500 to 10000 feet in thickness and contains thin beds of' oolitic )ime- stane, arenaceous limestone and reddish quartzite, which are occasionally cross-bedded and ripple-marked. It is certainly interesting that this slate which was .deposited after the Sturian glaciation is, according to David (1932), loessic. Since Woodward described two trilobites from the Parara limestone of the peninsula in 1884, its fauna has been amplified by Etheridge (1889), Tate (1892), and Chapman (1918), yet its age has been thought various- ly to be Lower Silurian of Murchison by Tate (1882) and Woodward, Lower Cambrian by Tate (1892) and Upper Cambrian by Etheridge (1890). Later in 1898, the last author suggested roughly Cambrian for ith age, while the Upper Cambrian age was re-affirmed by Howchin (1907) and Chapman (1918). Basedow (1909), Chapman (1914), David (1982), Whitehouse (1936) and several others however considered it to be Lower Cambrian, following Tate's later opinion, while in 1935 I suggested that the two trilobites from the Yorke's peninsula are related to Middle Cambrian members. A glance at the fossil list inserted here will show that Ordovician and Cambrian members are mingled in the fauna in, question and this co-mingling is the reason why such adverse opinions have been expressed. It has since been found, however, that most of the original generic references were incorrect. Neither Orthisina comptanor Orthis? peculiaris is properlyplaced in the genus. HenceWalcott (1912) has alreadysuggested Nissusia for the former and Kutorgina for the latter, the two generaranging fromLower to MiddleCambrian. Tate'sStenotheca rugosa is most probablya Helcionellaand Resser(1938) is correct in calling it by a new name,H, tc~ttei.Incidentally more speciesof Helcionellaare known in Lower Cambrianthan in MiddleCambrian. Ophileta subangulatawhich has a spiral keel alongthe middleof its apicalside of whorl is by no meansan Ophileta. It appears to me to be mostclosely allied to MiddleCambrian Pelagiella chronus walcott with whichI. (1939)established Proeccyliopteris. Platyceras etheridgei having a triangular

' Papers to which reference was madee are cited in the second paper (No. 67) of this Journal. *'* I wish to express my thanks to Prof . T. Kato for giving me encouragement and for reading these companion papers at the academy. No. 8.] Cambrian Faunas in South Australia with a Brief Note. 485 false area is not a gastropod. Walcott considered it as a Middle Cambrian atremate brachiopod closely allied to Micromitra (Paterina) superba, but as noted by him, the ventral valve is extraordinarily high. Furthermore, because it appears to have a foramen at, the apex, I think it is more probably an Acrotreta. This genus, though it occurs througbi Cambrian and to some extent also in Ordovician, flourished most in Middle Cambrian. Hyolithid like H, conularioides and H. communis are also common- ly met with in the Middle Cambrian faunas, although a deep longitudinal groove provided with a sharp ridge on each side in the former species is unusual. The occurrence of Salterella is of course confined to the Lower Cambrian Strata (Kobayashi, 1937), but .S. planoconvexa does not belong to the genus because it has no.central tube and its conical tabulae are fused. On these accounts it agrees with Biconulites which was founded on Middle Cambrian B. grabaui from Shansi (Teilhard, 1931). Later Salterella hardemanni Foord,1890, from the Lower Cambrian of Kimberly was referred to the genus (Spath,1936). It should be noted here that these two species of Biconulites have no longitudinal groove as in planoconvexa. Incidentally, this was found in the lowest fossil horizon jn the Cambrian of South Australia which is located 500 feet below the archaeocyatliid limestone.

Older Palaeozoic Fossils from the Yorke's Peninsula. Original reference Revised reference Girvanella sp. Hyalostella sp. Protopharetra (?) scoularis Etheridge Protopharetra or Metaldetes Ethmophyllum hindei Etheridge Ethmophyllum Coscinocyathus tatei Etheridge Coscinocyathus ? Orthis ? peculiaris Tate Kutorgina Orthisina compta Tate Nissusia Ambonychia (?) macroptera Tate 1 opteridae or Machaeridia Ophileta subangulata Tate Proeccyliopteris Plat'ceras eheridge Tate Aerotreta or Micrarnitra $tenotheca rugosa Hall by Tate HelcioneUQ tatei Resser Hyolithes communis B}llings by Tate Hyolithes conulariotid es Tate Dolichometopus tatei Woodward Microdiscus subsagittatus Tate Pararaia tatei~(Woodward) Olenellus ? pritchardi Tate Conocephalites australis Woodward Xorkella anstralis (Woodward) Ptychoparia howchini. Etheridge Leperiditia eapsella Chapman Univalved Conchostracan Leperiditia tatei Chapman Univalved Conchostraean Isochilina sweeti Chapman Univalved Conchostracan

So revised, the Ordovician aspect first seen in the list becomes obscured and the Lower and Middle Cambrian appearance emerges un- mistakably. But more important for age-determination are the trilobites on which I carried out a study with the plaster-casts of the type specimens. As a result of this study it was determined that Dolicho- rnetopus tatei, Microdiscus subsagittatus and Olenellus pritehardi belong to one species and Conocephalites australis and Ptychoparia howchini to another, but that they do not belong to any of the formerly suggested genera. The former species is called here Pararaia tatei and the latter Yorkella australis. Pararaia and Yorkella are, as will be discussed in the next paper, intimate relatives respectively of Lorenzella and Solenopleura s. str. both of which are typical members of the Middle Cambrian faunas. It must be noted here in passing that 486 T. KOBAYASHI. [Vol. 18,

a species of protolenid was contained among the plaster-casts at hand . An enigma in the Parara fauna is Ambonychia (?) macroptera which is a small fragmentary shell less than a quarter of an inch in length. If it is really a pelecypodits proper position may be found somewhere in the Aviculidaeor the Conocardiidae,instead of Ambonychiafrom which it is quite distinct. Whatever the genus of Pelecypodait belongsto, it is known at present that undoubted members of Pelecvpodaappear first in Ordovician. It appears to me, however, to be more probably a new univalvel Conchostracanor a new Machaeridian,because its resemblance to Technophorusand Pseudotechwphorus (Kobayashi, 1933) as well as isolated plates of Turrilepis can hardly be overlooked. As noted elsewhere(Kobayashi , h1936B), the occurrence of the Eopteridae to which the former two genera belong is, owever, restricted to the Ordovician except Upper Cambrian Wanwania cambrica. The Machaeridiaon the other hand occur in the strata from Ordovician to Devonian, b ut probably not in Cambrian (Withers, 1926). Which one of these suggestions is correct, must remainnunknown until the specimenis re-studied, but at any rate it is recognized that thEeenigmatic macroptera is allied to Upper Cambrian and later organisms. As regards Chapman'sthree species of ostracod Ulrich and Bassler (1931) suggested their being Cambrian univalved Conchostracans; Etheridge's archaeocyathids were revised by Talyer (1910); Girvanella and Hyalostella are not important for age- determihation because they are wide ranged. Cambrian in the Flinders Range and outer Places in South Aqu tralia In connection with the upper limit of the Eo-Palaeozoic formation in South Australia one must bear in mind that Walcott (1908) denominated Etheridge's Orthis (or Orthisina) sp. 1905, from Wirrialpa in the Flinders Range as Hitenella etheridgei because Huenella is known to have lived. from Upper Cambrian to Lower Ordovician . Further- more he placed Orthis (?) tatei Etheridge,1905, in the Eoorthis remnicha group. These together with a dubious Ambonychia suggest that the top of the limestone formation in question is possibly younger than Middle Cambrian. David (1932) and Whitehouse (1936), however, re- grded it as early Middle and Lower Cambrian, the former author classifying it into four stages. The highest containing Obolella wirrial- pensis Etheridge, 1905, was considered as early Middle Cambrian, not- withstanding the fact that other species of Obolella are all Lower Cambrian. The next is called the Redlichia stage and the third, the Protolenws stage. I cannot understand, however, how. the superposition of the secondabove the third stage was determined, because so far as I am aware, an undescribed protolenid is known only from the Yorke's peninsulawhile Redlichia is distributed from the Flinders to the northern territpries as far as the KimberIey district. The arehaeocyathidlime- stone is placed at the lowest of the four stages. Although it may be proper to con- sider the archaeocyathid limestone of the continent to be mostly.Lower Cambrian (Davjd, 1927),we must wait for future research to tell us whether the archaeocyathid limestones at Normanville and Sellick's Hill to -the south of Adelaide, Ardrossan and C urramulka of the Yorke's peninsula, Wilson and Kanyaka nearby, Blinman and Wirrialpa in the Flinders range, Ajax mine near Beltana, in the Macdonnellrange and the Kimberley district lie all in the same horizon,because only a few species are common among these localities. Furthermore it must be remembered that archae- cyathids in Shansi and Spiti, insofar as can be' judged from the trilobites found in as- sociation (Kobayashi, 1942), are undoubtedly early Middle Cambrian, although the archaeocyathidwas much more developedin the Lover Cambrian period. Thus there are many questions which must by solved by stratigraphic studies. The succession of the Cambrian formation in the Ajax Mine (Taylor, 1910) is as follows : No. 8.] Cambrian Faunas ` in South Australia with a Brief Note. 487 6.. Cliff-making massive brown limestone, 540 feet thick. 5. Gray and brown limestones with fossils gradually becoming abundant downward, 450 feet thick. 4. Silicified archaeocyathid reef limestone, 150 feet thick. 3. Gray and brown stratified limestones containing some fossils, 300 feet thick. 2. Limestone containing black shale, 300 feet thick. 1. Quartzite. Near Wirrialpa sheep station exposures of limestones full of Obolella or sponge spicules, or Girvanella bearing 2 inch nodules are found above the archaeocyathid limestone ; and red sandstones in still higher horizon which also contain lenses of Obolella limestone, are cross-bedded and intercalated with purple slates ; burrows and trails of worms were found in calcareous slabs there. At the entrance of the Parachilua Pass in the Flinders, the Lower Cambrian formation consists of archaeocyathid limestone, upper and lower marbles and dark oolitic limestone in descending order. (Howchin, 1918). Thus the three sections are distinct from one another and the above mentioned one of the Yorke's peninsula is also distinct from any of these. Assuming that the main archaeocyathid limestone is a horizon- marker, however, the rock succession may tentatively be simmarized as below. Flinders range Yorke's peninsula Red sandstone and slate. Obolella limestone (cliff-making ?) Pararaia-Yorkella limestone of Wirrialpa. Archaeocyathid limestone Archaeocyathid limestone Marble and oolitic limestone Dolomitic limestone Quartzite Thin basal sandstone The Cambrian fauna of South Australia is not very copious, if about one hundred species of archaeocyathids are excluded, but there are several which I have not mentioned before, because they are not important for age-determination. They are as follows : 1) Protohyalostelia mawsoni Chapman, 1940, was described from a horizon a little above the main Arehaeocyathid reef in der Flinders range. 2) Radiolarians resembling Carposphaera and Cenellipsis . were found in Lower Cambrian cherts near Adelaide (David and Howchin, Proc. Linn. Soc. N. S. Wales, vol. 21, 1897). 3) A few algae and non-archaeocyathian sponges are described from the archaeocyathid limestone by Bedford. Among these I have actually examined only some of the very important trilobites. For the rest my comments are based solely on their descriptions and illustrations given by previous workers. Therefore, if these specimens are actually seen, some of these comments may have to be withdrawn. On the basis of these trilobites, however, I have become convinced that the Eo-Palaeozoic formation in South Australia extends from the Lower Cambrian at least to a certain part of Middle Cambrian, although I have yet to be convinced that deposits of a still younger age are contained. Though quite tentative, the following zonation is suggested from the palaeontological point of view. 4. Huenella zone of Wirrialpa. 3. Psrara limestone proper. 3 b Pararaia-Yorkella zone of the Yorke's peninsula. 3 a Redlichia zone in the Flinders. 2. Main archaeocyathid limestone of Ajax. 1. Planoconvexa zone of the Yorke's peninsula. 488 T. KOBAYASHI. [Vol. 18,

Huenella limestone, if Walcott's generic reference is correct, is probably Upper Cambrian or even Lower Ordovician ; Pararaia-Yorkella limestone on the other hand is probably early Middle Cambrian and this judgement agrees with the stratigraphic fact that, Yorkella occurs at the top of the archaeocyathid-bearing limestone at Curramulka ; the Obolella and Protolenus horizons may be located somewhere near the Redlichia and Pararaia horizons respectively. The name, Parara limestone, which comprises various fossil beds can be used to designate the Eo-Palaeozoic formation in South Australia which lies on the archaeocyathid bearing Ajax limestone. Cambro-Ordovician Formations in. Australia :-Thus the Lower Cambrian is better represented in South Australia than in any other area in the continent but for the Redlichia and later stages Of the system the best place lies in Western Queensland and its adjacence on which Whitehouse has published valuable contributions in . recent years (1936, 39). Of the Cambrian in the Kimberley district and the Mac- donnell range and also of the Heathcotian including the Dolodrook limestone of Victoria and the Dundas slate of Tasmania, on the other hand, little is as yet known. I have discussed the latter two on former occasions (1935, 40 c) and concluded that the Heathcotian and Dolodrook faunas are Middle Cambrian instead of Upper Cambrian or younger as suggested by Gregory (1902), Chapman (1917), and others. It is however probable that the age of the Heathcotian extends into Lower Cambrian because Olenellus ( = Redlichia ?) and Salterella ( = Biconuli- tes ?) were reported to occur in the phosphate mine of Mansfield, near Melbourne (Howitt, 1923). Brief notes should be added here to the Cambrian in the Kimberley district and Macdonnellrange. The Cambrian formation in the Ord River basin in the Kimberley district consists of chocolatecoloured sandstonesin the upper, fossiliferous limestones with intercalations of shales and mudstones in the middle and massive limestones in the lower part. At Mt. Panton the limestone bed, 38 feet thick, containingLinguletla, Orthis-like brachiopod,Biconulites and Redlichia forresti (Etheridge, MS in Foord), is underlain by Biconulites-bearingbeds of 200 feet composed of red and green shales. A thin quartzite layer occurs at its base. An underground sequence was determined by a drill of 1196 feet in depth at Oakes-Duraok. Girvanella and other fossils were found in a blue limestone bed beneath a variagate mudstone bed both cf which exist at the degth of 66 feet from the surface. From this point to the depth of 471 feet there are gypsum bearing shales and mudstones,whence to 778 feet there are beds of shales, mudstone,limestone and chert, these being underlain by Antrim basalt flows (Blatchford, 1927). The upper part of these strata which yielded Sphaerocodium, G 'rvanella, radiolarians,, encrusting f oraminif ers, archaeocyathid, stroma- thoporoid (?), Biconulites hardemanni, univalved conchostracans (?) and other fossils and which used to be called Ord River limestone or Salterella (i, e. Biconulites) limestone of the Negri series is unquestion- ably Lower Cambrian, but it is probable that the subjacent part on the basalt belongs to the Adelaide series em. In the Macdonnel)range it is quite certain that the Pataoorta series comprisesthe Ajax limestone because Dicfyocyathus macdonnelli Bedford was described. Because Girvanella is frequently found, ~s in Eastern Asia, in the Redlichia stage in the Flinder~.as well as in the Kimberley district, the occurrence of the alga in the range suggests that Redlichia may be found there. No. 8.] Cambrian Faunas in, South Australia with a Brief Note. 489

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H 490 T. KOBAYASHL [Vol.^18,

As the result of untiring efforts by Hall, Pritchard, Keble, Benson, Harris, Thomas and others the Ordovician graptolite f acies in Victoria, New South Wales and New Zealand has been thoroughly worked out while the shelly f acies of the same age in the Southwestern Pacific province is not as well known. Therefore I published a paper recently (1940 c), to compile the results of my studies (1936, 40 A-B) and to comment on the known facts, because I had opportunities to study some Australasian fossil collections. After I presented a paper on the Tim Sha fauna of Tasmania,Lewis (1940)reported the fact that the fossiliferousTim Sha mudstone, 100 feet thick, is overlain by the Junee blue limestone of 500 feet and underla~ by a thick quartzite formation of 2000 feet. The basal conglomerateof this quartzite formation appears to overlie the Dundas slate unconformably. Another new fact is the discovery of Bathmoceras, which extendedthe lower limit of the Larapintine series to Llanvirnian (Teichert, 1939). On the basis of all these facts so far available a correlation of the Cambro-Ordovician formations in Australasia is tentatively made as shown in the accompanying table, and at the same time I have pre- pared here a palaeogeographlc map of the Eo-Palaeozoic and older periods. History of the Nullagine basin*** Whether the Nullagine lavas are older than the Antrim-Wooltana basalt as considered by David (1932) remains as yet an open question. But assuming that these volcanics are contemporaneous, the Proterozoic deposits in the Nullagine

Map showing the distribution of the Proterozoicand Eo-Palaeozoic Formations in Australasia. basin in Central and Western Australia are classified in the table into the Adelaide series (em) above and the Nullagine (em) below with an aid of the basalt in between. In the ensuing Cambro-Ordovician period there were the Ord River and the Georgia transgressions, and Ninmarro ingression (?) and the Larapantine transgression. The purple slate, Templeton and Pituri clastic beds and probably the Caroline Creek

*** A lengthy discussion on the subject of this chapter is given in my paper "Geology of Australia with special reference to Eo-Palaeozoic and older formations and their basement complex," (in preparation). No. 8.] Cambrian Faunas in South Australia with a Brief Note. 491 sandstone and the sub-Tim Sha quartzite are products of the time of regressions. Thus the strandline oscillated to and fro, but the shifting of the strandline through these emergences and submergences shows that the Nullagine basin became tilted eastward or southeastward till at length the basin shifted in the same direction and at the same time shrank to a small geosynclinal basin of walhalla in eastern Victoria and its adjaeence at the time of the early Gotlandian regression. This was followed by the late Gotlandian ingression but the sea flooded then only on the southeastern part of the continent. The Eo-Palaeozoic formation deposited there can be classified into the near-shore and off-shore f acies. The former is a shallow sea deposif which is occasionally cross-bedded and ripple-marked ; the fauna contained comprises many benthos. The latter f acies consists of fine rocks and the organism contained are mostly pelagic and planktonic forms. The latter is embraced by the former from the north and west sides and the spilitic suite in the latter shows intrageosynclinal volcanism. This geosyncline of walhalla must be a progenitor of the Tasman geosycline in the Middle and Upper Palaeozoic periods.