Silicified brachiopod and bivalve fossils from the mid-Permian (Kungurian−Roadian) Wandrawandian Siltstone of the southern Sydney Basin, southeastern Australia: implications for taphonomy and silicification

A ca 6 cm-thick microfossil coquina bed dominated by plastically deformed and siliceous tubular test fragments is described for the first time from the Lower Permian (Artinskian) Pebbley Beach Formation of coastal and glacial marine origin in the southern Sydney Basin, southeastern Australia. The test fragments are mostly very large, straight, smooth, nearly cylindrical in shape, and the test walls are composed mainly of homogenous microcrystalline quartz grains. This homogeneous siliceous test-wall microstructure is interpreted to have resulted from diagenetic alteration of what might have been originally organic-cemented, flexible (not rigid) and siliceous agglutinated walls. As such, this microscopic tubular test is identified as Sansabaina acicula, an organic-cemented siliceous-agglutinated foraminifera originally described from the Kungurian Quinnanie Shale in the Carnarvon Basin of Western Australia. The discovery of Sansabaina acicula supports the previous interpretation of the studied strata being deposited in a stressed marine shelf environment. G. R. Shi [guang@uow.edu.au], Sangmin Lee* [lsam@uow.edu.au], Paul F. Carr [pcarr@uow.edu.au] and Brian G. Jones [briangj@uow.edu.au], School of Earth, Atmospheric and Life Sciences, University of Wollongong, Northfields Avenue, NSW 2522 Australia David W. Haig [david.haig@uwa.edu.au], Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia.

A new low-diversity and low-abundance brachiopod fauna comprising seven species in four named genera and three indeterminate genera is described for the first time from the Pebbley Beach Formation in the southern Sydney Basin, southeastern Australia. Among the brachiopods described and illustrated, one new ingelarelloidean (Family Notospiriferidae) species (Tabellina laseroni sp. nov.) and one new terebratulid (Family Gillediidae) genus and new species (Paragilledia kioloaensis gen. et sp. nov.) are proposed. In addition, the status and validity of two strophalosioidean species previously described from the Pebbley Beach Formation are also discussed and revised. The age of the Pebbley Beach Formation is discussed and, based on the brachiopod fauna documented here and other stratigraphic and geochronological constraints, is considered to be late Sakmarian to early Kungurian.G.R. Shi [guang@uow.edu.au]* and S. Lee [lsam@uow.edu.au], School of Earth, Atmospheric and Sciences, University of Wollongong, Northfields Avenue, NSW 2522 Australia; J.W. Waterhouse, Oamaru, New Zealand.

Depositional environment, organic matter sources, and variable 17α(H)-diahopane distribution in Early Permian samples, southern Sydney Basin, Australia

Permian sediments occur throughout the southern Sydney Basin, exposed on the coastline south of Wollongong, and penetrated by various boreholes. This study uses outcrop samples and samples from three boreholes held by NSW Resources and Energy at the core library at Londonderry (Department of Mines Callala DDH1 [Callala-1] from near Callala Bay, Elecom Clyde River DDH07 [ECR-7] from near Nowra, and Elecom Clyde River DDH01 [ECR-1] from near Wingello). Formations analysed include the Berry Siltstone, Nowra Sandstone, Wandrawandian Siltstone, the Snapper Point Formation, the Pebbley Beach Formation and the Yarrunga Coal Measures. The objectives are to determine the depositional environment, organic matter inputs, thermal maturity and petroleum generation potential of these formations, which were deposited when Australia was close to the South Pole. The rocks at outcrop and in ECR-1 are in the early oil window, while rocks from near Jervis Bay (Callala-1, ECR-7) are in the gas window. Total organic carbon content is heterogeneous and varies from 0.2–6.7%. The rocks were deposited in oxic to suboxic depositional environments. The Wandrawandian Siltstone contains biomarkers dominated by very high amounts of diahopanes and diasteranes, whereas these biomarkers are of lower relative abundance in the other formations. This is suggestive of a clay-rich sediment in an oxic, acid-catalysed depositional environment, with enhanced diagenetic alteration of the biomarkers, or alternatively an unusual organic input. The Pebbley Beach and Snapper Point formations are characterised by biomarker distributions dominated by terrigenously sourced terpanes (e.g. C24 tetracyclic terpane and C19 tricyclic terpane), corroborating their deltaic and shallow marine depositional environments, respectively. In contrast, the Wandrawandian Siltstone contains dominantly C21, C23, and C24 tricyclic terpanes. The Pebbley Beach Formation contains high amounts of C29 relative to C28 and C27 steranes, also consistent with a dominant terrigenous input.

LUO, M. & SHI G.R., February 2017. First record of the trace fossil Protovirgularia from the Middle Permian of southeastern Gondwana (southern Sydney Basin, Australia). Alcheringa 0, 000–000. ISSN 0311-5518.This study reports the first examples of well-preserved chevronate trails referable to Protovirgularia longespicata De Stefani, 1885 from the early Middle Permian (Roadian) upper Wandrawandian Siltstone of the southern Sydney Basin, southeastern Australia. The highly meandering trace with closely spaced, papillate chevrons is interpreted to have been produced by the locomotion-feeding behaviour of certain protobranch bivalves in an offshore environment. The dense trails occurring on the upper bedding planes of pebbly siltstone may represent a gregarious lifestyle, where junior and senior individuals of the trace-maker bivalves coexisted while moving within sediments. The Wandrawandian Protovirgularia also represents the first known occurrence of this ichnotaxon from a glaciomarine environment in the Permian eastern Gondwana. The global record of Protovirgularia occurrences suggests that these trails had a wide environmental distribution since the Cambrian, and there is no obvious difference in the environmental distribution of Protovirgularia after the Permian‒Triassic transition.Mao Luo [m.luo@deakin.edu.au] and G.R. Shi [guang.shi@deakin.edu.au], Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood Campus, 221 Burwood Highway, VIC 3125, Australia.

A study of the stratigraphic units within the southern Sydney Basin has led to the recognition of Upper Carboniferous and Lower Permian sediments. Terrestrial valley-fill sediments up to 228 m thick define a palaeodrainage system active during the Upper Carboniferous. These sediments belong to the proposed Talaterang Group and comprise the Yadboro Conglomerate, Tallong Conglomerate, Burrawang Conglomerate, Yagers Conglomerate, Pigeon House Creek Siltstone, and Badgerys Breccia. Palynological data indicate that at least the lower part of the Talaterang Group can be correlated with the Seaham Formation of the Hunter Valley. The Talaterang Group is overlain disconformably by the Clyde Coal Measures (up to 41 m thick) and the Yarrunga Coal Measures, which are in part laterally equivalent to, and overlain by, the Conjola Sug-Group (lower part of the Shoalhaven Group). The Clyde Coal Measures may be correlated with the interval extending from the Rutherford Formation to the Greta Coal Measures of the Hunter Valley. Marine terrigenous sediments of the Conjola Sub-Group (420 m thick) were deposited during a transgression which began in the Early Permian (Allandale equivalent to, and overlain by, the Conjola Sub-Group (lower part of the Shoalmation, Pebbley Beach Formation, and Snapper Point Formation, and are in turn overlain by the Ulladulla Mudstone and Wandrawandian Siltstone (together up to 120 m thick); they were derived from the west and south, and were deposited in a shallow marine shelf environment into which exotic megaclasts were ice-rafted.

The organic geochemistry of Permian high latitude sediments in two boreholes in the southern Sydney Basin, New South Wales, Australia

Elements of a high-latitude (∼60–70°S) and low-diversity early Kungurian (Cisuralian/Early Permian) brachiopod fauna have been sporadically reported from the sandstone-dominated Snapper Point Formation (SPF) in the southern Sydney Basin of southeastern Australia for more than a half-century, but a detailed description of this fauna is not yet available. In this paper we describe 12 brachiopod species and an indeterminate ingelarellid from the SPF, including one new species (Tasmanospirifer jervisbayensis sp. nov. Waterhouse & Lee). Though this brachiopod fauna is evidently associated with an interglacial stratigraphic interval, its taxonomic characteristics overall resemble those from stratigraphically bounding glacial intervals. This association is interpreted to indicate persistence and the strong endemic nature of the Permian Eastern Australian biogeographic province in high-latitude eastern Gondwana, regardless of glacial/interglacial climate states during the Cisuralian. Biostratigraphically, the SPF brachiopod fauna is divisible into two distinctive stratigraphic assemblages: the Notospirifer cf. triplicata–Simplicisulcus sp. Assemblage in the lower part of the formation and the Johndearia brevis–Sulciplica transversa Assemblage in the upper part, each distinguished by a set of unique species. Sangmin Lee [sangminlee76@gmail.com] and G. R. Shi [guang@uow.edu.au] School of Earth, Atmospheric and Life Sciences, University of Wollongong Faculty of Science Medicine and Health, Northfields Avenue, Wollongong, NSW 2522, Australia Bruce Runnegar [runnegar@ucla.edu] Earth, Planetary and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1567, USA J. B. Waterhouse [permia@xtra.co.nz] Oamaru, Oamaru, New Zealand.

Gong, Y.-M., Shi, G.R., Zhang, L.-J. & Weldon, E.A. 2009: Zoophycos composite ichnofabrics and tiers from the Permian neritic facies in South China and south-eastern Australia. Lethaia, Vol. 43, pp. 182–196. Zoophycos composite ichnofabrics (ZCI) comprising two or more suites of the same form of Zoophycos are widespread and densely distributed in Early and Middle Permian (Cisuralian–Guadalupian) neritic limestones (Qixia and Maokou Formations) of palaeotropical origin in the Laibin area, Guangxi, South China. Similar ZCI also occur in neritic greywackes of glaciomarine origin from the Middle Permian (Guadalupian) Westley Park Sandstone Member (Broughton Formation) in the southern Sydney Basin, south-eastern Australia. Zoophycos from both regions consists of planar spreite with major and minor lamellae and a cylindrical tunnel interpreted as a marginal tube and/or axial shaft. The cylindrical tunnel is herein considered to be an essential component of Zoophycos, and thus can be used to define and characterize the morphological variability of Zoophycos. It is suggested that the variation of spreite and major and minor lamellae originated from the different morphologies and migration manners of the cylindrical tunnel. The shallowest, shallow, middle and deepest Zoophycos tiers have been distinguished in ZCI on the basis of cross-cutting relationships, the soft-sediment deformation and the contrast in colour between Zoophycos and its host rock. The multiple tiers may represent the substrate consistency spectrum from a softground through a stiffground to a firmground. The different Zoophycos tiers may have been constructed by tracemakers of either different or the same taxonomic affinities in response to the gradual accretion and lithification of sediment layers on the seafloor. The tracemakers appeared to be very sensitive to neither climate nor lithology. The width of the planar spreiten of Zoophycos decreases slightly with the depth of tiering in ZCI. □Composite ichnofabric, Permian, South China, south-eastern Australia, tier, Zoophycos.

Seven major lithofacies are present in the Lower Permian sediments of the Jervis Bay area (southern Sydney Basin). These facies, which are areally extensive, are members of the Pebbly Beach Formation (facies A), the overlying Snapper Point Formation (facies B-F) and the Wandrawandian Siltstone (facies G).Facies A to D represent a regressive shoreface succession which passes upwards into lagoonal and marsh sediments. They were deposited during the Snapper Point regression. Currents were predominantly long-shore with rip and onshore and offshore storm current components.Facies E to F constitute a regressive (i.e. shoaling upwards) spit profile which Accreted by longshore progradation during the early stages of the Wandrawandian transgression. They form the upper part of the Snapper Point Formation.Facies G comprises sandy muds of the Wandrawandian Siltstone which were deposited in a marine embayment at temperatures below 0°C as evidenced by glendonites (pseudomorphs after thenardite). The muds represent the culmination of the Wandrawandian transgression which followed upon the disruption of sediment supply to the spits and their consequent inundation.This depositional history resolves earlier conflicting interpretations of this part of the southern Sydney Basin sequence. It provides a better understanding of the origin of the Snapper Point Formation, which has been a common target for onshore petroleum exploration drilling.

A mid-Permian (late Kungurian) micro-dolerite dyke/sill complex located at Kinghorn Point intruded into the then unconsolidated upper Wandrawandian Siltstone of the lower Shoalhaven Group, southeastern Sydney Basin. The dark grey siltstone was deposited in the deeper part of a coastal seaway characterised by northward-directed paleocurrents, with a Cruziana ichnofacies, crinoid stem fossils and abundant glendonites indicating a cold climate. Thin periodic storm deposits, or tempestites, of fine-grained sandstone of volcanogenic origin are scattered through the siltstone. These paler sandy beds were probably derived from island volcanoes to the south or southeast, indicating that regional volcanism was pervasive during this glacial episode. Evidence for penecontemporaneous igneous emplacement into mid-Permian wet unconsolidated shallow marine sediments includes: destruction of primary sedimentary structures caused by extensive interaction and intermingling between the sedimentary and igneous materials, the presence of brecciated contacts and peperite, angular and rounded dolerite fragments in the siltstone, fluidisation and entrainment of the sediments into cooling and flow fractures in the magma, and the presence of tube-like flow features. There are also hyaloclastite and baked sediments along the contact margins, fumaroles and vesicles within both the sediment and magma. High vesiculation is characteristic of intrusion near the surface, and possibly extrusion at the sediment–water interface. The geochemistry of the intrusion, especially key element ratios of the high-field-strength, major and trace elements, is very different from that of the shoshonites of the nearby Permian (mid Wordian to Capitanian) Gerringong Volcanics, having much lower Zr/TiO2, Nb/Y, Nb/Zr, K2O, P2O5, Rb, Th, U, Y, Zr and Nb, and higher MgO, suggesting they are unrelated. This indicates that the Kinghorn Point intrusion was associated with an earlier intermediate pre-Gerringong Volcanics phase, or it may be distinctive and unrelated. Magmatic geochemical comparisons further afield along the northern Sydney Basin and Tamworth Fold Belt boundary coasts show that volcanism was pervasive during the Wandrawandian glacial episode and that regional mid-Permian mafic volcanism was well evolved in the southern Sydney Basin during sedimentation. KEY POINTS A mid-Permian syndepositional dolerite intrusion at Kinghorn Point shows classical peperite and soft-sediment deformation features. Previously unreported mafic tuffaceous sandstone beds within the Wandrawandian Siltstone were probably derived from island volcanoes to the south or southeast. Geochemistry of the intrusion shows that it is not related to the mid Wordian to Capitanian Gerringong Volcanics. Regional volcanism was pervasive during the Wandrawandian glacial episode along the southeast Panthalassan margin of Gondwana.

The Sydney-Bowen basin in eastern Australia is an elongate back arc-converted foreland basin system situated between the Lachlan Fold Belt in the west and the New England Fold Belt in the east. The Middle Permian Wandrawandian Siltstone at Warden Head near Ulladulla in the southern Sydney Basin is dominated by fossiliferous siltstone and mudstone, with a large amount of dropstones and minor pebbly sandstone beds. Two general types of deposits are recognized from the siltstone unit in view of the timing and mechanism of formation. One is represented by the primary deposits from offshore to subtidal environments with abundant dropstones of glacial marine origin. The second type is distinguished by secondary, soft-sediment deformational deposits and structures, and comprises three layers of mudstone dykes of seismic origin. In the latter type, metre scale, laterally extensive syn-depositional slump deformation structures occur in the middle part of the Wandrawandian Siltstone. The deformation structures vary in morphol-ogy and pattern, including large-scale complex-type folds, flexural stratification, concave-up structures, faulting of small displacements accompanied by folding and brecciation. The slumps and associated syn-sedimentary structures are attributed to penecontemporaneous deformations of soft sediments (mostly silty mud) formed as a result of mass movement of unconsolidated and/or semi-consolidated substrate following an earthquake event. The occurrence of the earthquake event deposits supports the current view that the Sydney Basin was located in a back-arc setting near the New England magmatic arc on an active continental margin during the Middle Permian.

N-3 pufa status predicts non-alcoholic fatty liver disease (NAFLD) in older Australians

Diverse assemblages of helcionelloid molluscs and mollusc-like microfossils are described from the upper Henson Gletscher Formation (Cambrian, Miaolingian Series, Wuliuan Stage) of Lauge Koch Land and western Peary Land, North Greenland (Laurentia). The fauna compares closely to an assemblage of similar age from the Coonigan Formation of Australia, although the latter is preserved as silica replicas while the North Greenland fossils are dominantly preserved as phosphatized internal moulds. These internal moulds often retain a detailed impression of the inner surface of the shell, with a fine pitted texture typically present. Prominent deep grooves on the sub-apical surface in the erect helcionellids Dorispira and Erugoconus, corresponding to ridges on the shell interior, seem to be associated with control of water flow through the mantle cavity. Well-developed shell pores, preserved as tubercles on the internal mould, are common in species of the laterally compressed Mellopegma. New taxa: Dorispira avannga sp. nov., Dorispira septentrionalis sp. nov., Dorispira tavsenensis sp. nov., Dorispira tippik sp. nov., Erugoconus acuminatus gen. et sp. nov., Scenella? siku sp. nov., Sermeqiconus gen. nov., Tavseniconus erectus gen. et sp. nov., Vendrascospira troelseni gen. et sp. nov., Vendrascospira frykmani gen. et sp. nov.

Distribution of silicification intervals throughout the Barra Velha and Itapema formations: Host rock controls and chronology of silica precipitation (Pre-Salt, Santos Basin, Brazil)