Taxonomy, evolution and biostratigraphy of the Ordovician conodont genera Triangulodus and Tropodus

Platform margins, reef facies, and microbial carbonates; a comparison of Devonian reef complexes in the Canning Basin, Western Australia, and the Guilin region, South China

The conodonts documented by Watson form one of the best-known middle Darriwilian faunas from Australia. The present contribution is based on the re-examination of this material. Thirty-one conodont species from the subsurface Goldwyer and Nita formations of the Santalum 1 A drill core section of the Canning Basin, Western Australia are documented and described, including two new species, Belodina watsoni sp. nov. and Scalpellodus percivali sp. nov. The revised fauna is characterized by diagnostic species, namely Histiodella holodentata, Histiodella triangularis, and Eoplacognathus pseudoplanus. It provides compelling evidence to correlate this stratigraphic interval represented by the upper part of the Goldwyer and overlying Nita formations in the Santalum 1 A drill core section to the Histiodella holodentata or Eoplacognathus pseudoplanus biozones of middle Darriwilian age. However, in the Canning Basin, the faunal change signaled by the disappearance of H. holodentata and appearance of E. pseudoplanus reflects shifting of depositional settings from intermediate to outer shelf environments to shallower inner shelf conditions, coinciding with a regional regression event. New taxonomic data also enable more precise regional correlation of middle Darriwilian rocks across the Canning Basin and the Amadeus and Georgina basins in northern-central Australia.Y.Y. Zhen [yong-yi.zhen@planning.nsw.gov.au], Geological Survey of New South Wales, Division of Mining, Exploration and Geoscience, Department of Regional New South Wales, W.B. Clarke Geoscience Centre, 947–953 Londonderry Road, Londonderry NSW, 2753, Australia.

Zhen, Y.Y., Normore, L.S., Dent, L.M. & Percival, I.G., 11 July 2019. Middle Ordovician (Darriwilian) conodonts from the Goldwyer Formation of the Canning Basin, Western Australia. Alcheringa 44, 25–55. ISSN 0311-5518Middle Ordovician conodonts attributed to 46 species were recovered from a stratigraphic interval spanning the Willara, Goldwyer and Nita formations in core sections from the Sally May-2 and Theia-1 petroleum exploration wells in the Canning Basin, Western Australia. The Histiodella serrata, Histiodella holodentata and Eoplacognathus pseudoplanus biozones are recognized in the lower and middle part of the Goldwyer Formation, indicative of an early–middle Darriwilian age. This revised conodont biostratigraphy enables more precise correlation with North America and North and South China. Several biogeographically distinctive conodont species, most likely of North Chinese origin, are recorded from the Goldwyer Formation. Their presence signals a strong palaeobiogeographic connection between the Sino-Korean Craton and the Canning Basin on the western margin of eastern Gondwana during the late Middle Ordovician.Y.Y. Zhen* [yong-yi.zhen@planning.nsw.gov.au], W.B. Clarke Geoscience Centre, Geological Survey of New South Wales, 947–953 Londonderry Road, Londonderry NSW 2753, Australia; L.S. Normore [leon.normore@dmirs.wa.gov.au]; L.M. Dent [louisa.dent@dmirs.wa.gov.au], Department of Mines, Industry Regulation and Safety, Mineral House, Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, Australia; I.G. Percival [ian.percival@planning.nsw.gov.au], W.B. Clarke Geoscience Centre, Geological Survey of New South Wales, 947–953 Londonderry Road, Londonderry NSW 2753, Australia;

Stratigraphy, correlation and sedimentary history of Adelaidean (late Proterozoic) basins in Australia

The Goldwyer Formation is widely known from the subsurface Canning Basin, Western Australia. Microfossils of acritarchs, chitinozoans, and conodonts, and macrofossil remains, indicate it was deposited in a normal marine environment in late Early to Middle Ordovician times (Late Arenig to Llanvirn). In Exploration Permit areas 143 and 225, the Formation is subdivided into four lithologic members, informally designated Units 1 to 4 in ascending stratigraphic order. Horizons within Unit 4, immediately underlying the prospective reservoir dolostones of the Nita Formation, are organic rich with between 0.5 and 6 per cent total organic carbon. Generative potential of these horizons, determined by Rock-Eval, averages 13 litres of hydrocarbon per tonne. A conservative estimate of the cumulative thickness of source rock with hydrogen index (HI) values of 300-900, using whole core fluorescence intensity, is 10 m. Thus, under optimum maturation conditions there is potential for generation of an estimated 61 × 109 barrels of liquids from Unit 4 within EP 143 and EP 225. These figures are based on an integrated analysis of 44 core samples from four fully cored 'slim holes' and cores from one conventional oil well. Kero-gen types and measures of organic maturity cannot be determined accurately from the standard Rock-Eval HI/Tmax crossplot. The dominant oil-prone kerogen in Unit 4 is Gloeocapsamorpha prisca Zalessky 1917 and palynological and gas chromatographic/mass spectrometric studies correlate it with Ordovician kerogens from the Baltic Basin, Michigan and Illinois basins, and Amadeus Basin. Gas chromatographic/mass spectrometric source rock-oil correlations show that oils from the Williston Basin (USA), Canning Basin, and Amadeus Basin are derived predominantly from G. prisca. Palaeogeographic reconstructions suggest that these areas lay within 5° north and south of an Ordovician equator and so provide data for further prediction of possible rich hydrocarbon source areas.

A new assemblage containing twenty-two species of trilobites and agnostids is described from the Goyder Formation (Cambrian Series 3) in the Ross River Syncline and Gardiner Ranges of the Amadeus Basin, Northern Territory, central Australia. New trilobite taxa described include the genus, Trephina gen. nov., and four new species Adelogonus prichardi sp. nov., Hebeia stewarti sp. nov., Liostracina joyceae sp. nov., and Trephina ranfordi sp. nov. Two agnostid taxa previously known only from Antarctica, Ammagnostus antarcticus Bentley, Jago Cooper, 2009 and Hadragnostus helixensis Jago Cooper, 2005, are also documented. Of the two agnostid species, the latter is the most age diagnostic, previously reported from the Cambrian Series 3 (Guzhangian; late Mindyallan; Glyptagnostus stolidotus Zone) Spurs Formation in Northern Victoria Land. This age for the Goyder Formation assemblage is supported by the co-occurrence of the trilobites Biaverta reineri Öpik, 1967, Blackwelderia repanda Öpik, 1967, Henadoparia integra Öpik, 1967, Monkaspis cf. travesi (Öpik, 1967), Nomadinis pristinus Öpik, 1967, Paraacidaspis? priscilla (Öpik, 1967), and Polycyrtaspis cf. flexuosa Öpik, 1967, also known from the late Mindyallan (G. stolidotus Zone) successions of the neighbouring Georgina Basin (Northern Territory and Queensland). The generic assemblage of the Goyder Formation is also similar to those from the Guzhangian (Mindyallan) of other parts of Australia (New South Wales, South Australia, and Western Australia), in addition to East Antarctica and North and South China.

The Devonian of Western and Central Australia consists of sedimentary rocks deposited in intracratonic basins. No igneous activity is known. Devonian rocks are scattered over more than one million square miles and fall into three divisions:5,000 to 10,000 feet of mainly Upper Devonian marine platform limestones and sandstones in the three western basins with laterally equivalent siltstone and shale in the Canning and Bonaparte Gulf Basins;Upper Devonian terrestrial fish-bearing quartz sandstone and associated siltstone and conglomerate in the Amadeus Basin (12,000 feet) and Dulcie (500 feet) and Toko (unknown thickness) synclines; andpoorly known probable Lower and Middle Devonian red-beds and evaporites in the Canning Basin (8,000 feet), barren quartz sandstone in the Amadeus Basin (3,000 feet), and vertebrate-bearing quartz sandstone in the Dulcie (1,500 feet) and Toko (500 feet) synclines.Except fr the Amadeus Basin, all these rocks are flat-lying to moderately tilted, and high-angle faults are the chief structural elements. Metamorphism is wholly absent except adjacent to major faults. Steep dips in the Devonian of the Amadeus Basin are related to folding. The rocks of the first division represent part of a depositional phase which continues into the Lower Carboniferous; divisions (ii) and (iii) are probably the end phases of depositional cycles which started before the Devonian.Interesting features of these rocks are the well-exposed and essentially undeformed carbonate reef complexes of the northern Canning Basin and the Bonaparte Gulf Basin, the thick Frasnian sandstones of the Bonaparte Gulf Basin, and the thick redbed-evaporite sequence of the southern Canning Basin. The reef complexes with their associated basinal facies provide prospects for petroleum production.

South China in Rodinia: Part of the missing link between Australia–East Antarctica and Laurentia?

Neoproterozoic shallow-marine and carbonate- rich strata of the northern Amadeus Basin, central Australia, comprise a geochemical record of Neoproterozoic seawater that facilitates correlation with other basins in Australia and worldwide. This study includes new carbon and oxygen isotope measurements of Cryogenian and Ediacaran carbonate in the northern Amadeus Basin that, in combination with previous data from Tonian strata of the Bitter Springs Formation, form a composite Amadeus Basin Neoproterozoic δC record. Key features of the Cryogenian-Ediacaran portion of this record include (1) negative δC excursions in cap carbonates overlying Cryogenian glacigenic deposits of the Areyonga and Olympic Formations (i.e., the Rasthof and Maieberg excursions, respectively); (2) a mid-Cryogenian negative excursion in the Ringwood Member of the Aralka Formation (seemingly correlative with the Taishir excursion of SW Mongolia); (3) a subsequent mid-Cryogenian positive excursion (the Keele Peak excursion) in the Limbla Member of the Aralka Formation; and (4) relatively low-magnitude excursions in the Ediacaran Julie Formation. In comparison with other Neoproterozoic stratigraphic successions, key portions of the overall Neoproterozoic δC record that appear to be absent from the Amadeus Basin based on existing data include large-magnitude negative excursions (Islay and Trezona excursions) that immediately preceded basaland terminal-Cryogenian (i.e., Sturtian and Marinoan, respectively) glaciations. These missing δC excursions are associated with significant unconformities in the Amadeus Basin. δC and δO from carbonate clasts in diamictite of the Areyonga and Olympic Formations suggest that deposition of Islay- and Trezona-equivalent strata was limited or nonexistent in the Amadeus Basin, as opposed to the possibility that these strata were deposited but subsequently removed by glacial erosion. Our new Amadeus Basin results refine Cryogenian and early Ediacaran correlations among the Amadeus Basin, Adelaide rift complex, and Namibia. The lower part of the Ringwood Member, which was deposited during early stages of the Cryogenian nonglacial interlude, includes two negative δC excursions that are also evident in previous results from the Tapley Hill Formation of the Adelaide rift complex. The upper part of the Ringwood Member contains abundant stromatolites and seems to correlate with Cryogenian stromatolite reefs of the Balcanoona Formation in the Adelaide rift complex. The overlying Limbla Member in the Amadeus Basin correlates with the Yankaninna, Etina, Amberoona, and Enorama Formations of the Adelaide rift complex, as well as carbonate from other continents that record the Keele Peak excursion. δC from the early Ediacaran Olympic cap of the Amadeus Basin is (1) comparable to previous results from the Maieberg and Elandshoek Formations in Namibia; and (2) consistent with diachronous deposition of Marinoan cap dolostone in the Amadeus Basin. Additionally, new δC from the Julie Formation of the Amadeus Basin is similar to previous results from the late Ediacaran Kuibis Subgroup in southern Namibia. These correlations underscore that Ediacaran strata of Namibia, as well as the Cryogenian nonglacial interlude strata of the Adelaide rift complex, are roughly an order of magnitude thicker than stratigraphic counterparts in the Amadeus Basin. The wide disparity in sedimentation rates implied by this finding is likely attributable to fundamental differences in the Neoproterozoic tectonic settings of the three locations.

Geochemical characteristics of the lower Silurian Longmaxi Formation on the Yangtze Platform, South China: Implications for depositional environment and accumulation of organic matters

First record of lower – Middle Ordovician (Tremadocian – Dapingian) carbon isotope (δ13Ccarb) chemostratigraphy in the Canning Basin, Western Australia; calibrated with geochronology/biostratigraphy and implications for global correlations

The stratigraphic overview presented in this chapter substantially updates and revises the last major review of the Ordovician rocks of Australia and New Zealand published 40 years ago. In the western two-thirds of the present-day continent of Australia, Ordovician sedimentary rocks are restricted to intracratonic basins. The Canning Basin (Western Australia) and Amadeus Basin (central Australia) contain the best known Lower and Middle Ordovician shallow marine successions. The eastern third of the continent, known as the Tasmanides, comprises multiple orogens (i.e. Delamerian, Lachlan, New England, Thomson, Mossman) that formed along the convergent East Gondwana Margin. As a result, volcanic and intrusive rocks are much more common in these orogens than in the intracratonic basins. Their deep-water depositional environments span 31 graptolite biozones. Slope and basinal siliceous sedimentary rocks are constrained by a newly defined set of 12 conodont biozones, complementing the conodont biostratigraphic scheme refined for shallow-water environments from the basal boundary of the Ordovician to the latest Katian. In some places, these conodont biozones are integrated with radiometric ages from tuff interbeds (e.g. Canning Basin). Ordovician graptolitic strata in the Buller Terrane of New Zealand share palaeogeographic links with those in the Bendigo Zone of the western Lachlan Orogen.

A diverse microvertebrate fauna is described from the Virgin Hills and Napier formations, Bugle Gap Limestone Canning Basin, Western Australia. Measured sections at Horse Spring and Casey Falls (Virgin Hills Formation) and South Oscar Range (Napier Formation) comprise proximal to distal slope carbonates ranging in age from the Late Devonian Frasnian to middle Famennian. A total of 18 chondrichthyan taxa are identified based on teeth, including the first record of Thrinacodus tranquillus, Cladoides wildungensis, Protacrodus serra and Lissodus lusavorichi from the Canning Basin. A new species, Diademodus dominicus sp. nov. is also described and provides the first record of this genus outside of Laurussia. In addition, the upper range of Australolepis seddoni has been extended to Late Devonian conodont Zone 11, making it the youngest known occurrence for this species. The Virgin Hills and Napier formations microvertebrate faunas show close affinities to faunas recovered from other areas of Gondwana, including eastern Australia, Iran, Morocco and South China, which is consistent with known conodont and trilobite faunas of the same age.

Inoculation of Eucalyptus urophylla with spores of Scleroderma in a nursery in south China: Comparison of field soil and potting mix

The Murraba Basin is a poorly known component of the Centralian Superbasin that extends across the Western Australia – Northern Territory border. An earlier reconnaissance reinterpretation by some of the authors significantly changed the inferred ages and order of stratigraphic units and demonstrated many similarities to the Neoproterozoic and lower Cambrian component of the nearby, and presumably contiguous, Amadeus Basin. Further refinements are now possible with the addition of detrital zircon geochronology of siliciclastic units in the area. Detrital zircon data show that the Hidden Basin beds, previously compared to the older Birrindudu Basin, are no older than lower Tonian, and have broadly similar detrital zircon age spectra to basal components of the Centralian Superbasin, particularly the metamorphosed Yeneena Basin that is inferred to be widespread beneath the Canning Basin to the west. The relationship of the Hidden Basin beds to the nearby Munyu Sandstone and other Supersequence 1 components of the Murraba Basin remains unclear, but the beds possibly represents the transition between Murraba and Yeneena Basin. A previous redefinition of the Redcliff Pound Group assigned this upper succession of the Murraba Basin to Supersequence 3 and 4 (upper Cryogenian to lower Cambrian) and suggested deposition of at least the upper part of the group was synchronous with the Paterson Orogeny. New detrital zircon data from the middle Murraba Formation and Erica Sandstone of the Redcliff Pound Group define age components consistent with recycling of zircon grains from Tonian metasedimentary basement of the southern Canning Basin, and its ~650–600 Ma felsic intrusive rocks that were uplifted during the Paterson Orogeny.