Middle and Early(?) Triassic foraminifera from the Northwest Shelf, Western Australia

1986 ◽  
Vol 16 (4) ◽  
pp. 313-333 ◽  
Author(s):  
R. S. Heath ◽  
M. C. Apthorpe
Keyword(s):  
Western Australia ◽  
Early Triassic

GEOCHEMICAL INTERPRETATION OF SOME OILS AND CONDENSATES FROM THE DAMPIER SUB- BASIN OF WESTERN AUSTRALIA

1982 ◽  
Vol 22 (1) ◽  
pp. 179 ◽  
Author(s):  
I. Brikké
Keyword(s):  
Chemical Composition ◽  
Western Australia ◽  
Land Plant ◽  
Early Triassic ◽  
Normal Alkane ◽  
Geological Interpretation ◽  
The Core ◽  
Strong Affinity ◽  
Strong Emphasis ◽  
Deep Source

Twenty oils and condensates from the Dampier Sub-basin have been analysed for their gross composition and normal alkane distribution.The chemical composition (GLC traces) enables two groups to be distinguished:Oils and condensates low in C22 + n-alkanes. These are essentially found in the Rankin Platform. In this group, the sample from Eaglehawk 1 shows characteristics of a bacterially-altered product.Oils richer in C22 + n-alkanes. These are found in the Lewis Trough, but also in the Rankin Platform/Kendrew Terrace where subtle differences may suggest different origins.The geological interpretation puts strong emphasis on time of trapping. The oils and condensates of the first group (except at Angel) are trapped at the contact with the 'Main Unconformity'. Oils formed earlier than the Neocomian have been destroyed, altered (Eaglehawk 1) or trapped in deeper reservoirs, so that only mature to very mature hydrocarbons (low in C22 + n-alkanes) were available for trapping after sealing by Neocomian shales. Maturity considerations indicate that a deep source within the core of the Rankin Platform unit (Middle/Early Triassic Locker Shale and/or older) is the most likely generator of these hydrocarbons.The oils of the second group, on maturity grounds and to some extent on type correlation, may originate from Jurassic sources in the Lewis Trough. Some oils attributable to the second group are present on the Rankin Platform and/or Kendrew Terrace trapped by intraformational/fault seals and having the full composition of crudes; however, lower land-plant contribution inferred from the n-alkanes, suggests a 'Locker Shale' origin.The source of the Angel hydrocarbons is more enigmatic, but their strong affinity with the hydrocarbons from the Rankin Platform points to a similarity of origin.

The Permian–Triassic boundary in Western Australia: evidence from the Bonaparte and Northern Perth basins—exploration implications

2009 ◽  
Vol 49 (1) ◽  
pp. 311 ◽  
Author(s):  
John Gorter ◽  
Robert S Nicoll ◽  
Ian Metcalfe ◽  
Robbert Willink ◽  
Darren Ferdinando
Keyword(s):  
Western Australia ◽  
Petroleum Reservoirs ◽  
Sedimentary Basins ◽  
Early Triassic ◽  
Seismic Profiles ◽  
Triassic Boundary ◽  
Carbon Isotopic ◽  
Geochemical Analyses ◽  
Permian Triassic Boundary ◽  
Isotopic Measurements

Several sedimentary basins in Western Australia contain petroleum reservoirs of Late Permian or older age that are overlain by thick shaly sequences (400–2,000 m) that have been assigned an Early Triassic age. The age of the base of the Triassic shales has been, and continues to be, contentious with strata being variously ascribed to the latest Permian (Changhsingian Stage) or wholly in the earliest Triassic (Induan Stage). In the Perth Basin the Permian-Triassic boundary appears to be located somewhere in the Hovea Member of the Kockatea Shale. In the Bonaparte Basin, the boundary would appear to be either in the uppermost Penguin Formation or at the boundary between the Penguin and Mairmull formations. The uncertainty of the boundary placement relates to the interpretation of the sedimentological, biostratigraphic and geochemical record in individual sections and basins. Major problems relate to the recognition, or even the presence of unconformities, complications related to the presence of reworked sediments and paleontological material (both conodonts and spore-pollen) and to the significance of geochemical shifts. The age of the basal Kockatea Shale (northern Perth Basin) and the basal Mt Goodwin Sub-group (Bonaparte Basin) is reassessed using palaeontological data, augmented by carbon isotopic measurements and geochemical analyses, supported by wireline log correlations and seismic profiles. The stratigraphy of the latest Permian to Early Triassic succession in the Bonaparte Basin is also revised, as is the nomenclature for the Early Triassic Arranoo Member of the Kockatea Shale in the northern Perth Basin. The Mt Goodwin Sub-group (new rank) is composed of the latest Permian Penguin Formation overlain by the Early Triassic Mairmull, Ascalon and Fishburn formations (all new).

Early Triassic (early Olenekian) life in the interior of East Gondwana: mixed marine–terrestrial biota from the Kockatea Shale, Western Australia

2015 ◽  
Vol 417 ◽  
pp. 511-533 ◽  
Author(s):  
David W. Haig ◽  
Sarah K. Martin ◽  
Arthur J. Mory ◽  
Stephen McLoughlin ◽  
John Backhouse ◽  
...  
Keyword(s):  
Western Australia ◽  
Early Triassic ◽  
Terrestrial Biota

scholarly journals Significance of Early Triassic conodont zones from Western Australia

2019 ◽  
Vol 2019 (1) ◽  
pp. 1-4
Author(s):  
John D. Gorter ◽  
Michael J. Orchard ◽  
Robert S. Nicoll ◽  
Darren Ferdinando
Keyword(s):  
Western Australia ◽  
Early Triassic

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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