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).

Nature and origin of the volcanic ash beds near the Permian–Triassic boundary in South China: new data and their geological implications

2019 ◽  
Vol 157 (4) ◽  
pp. 677-689 ◽  
Author(s):  
Binsong Zheng ◽  
Chuanlong Mou ◽  
Renjie Zhou ◽  
Xiuping Wang ◽  
Zhaohui Xiao ◽  
...  
Keyword(s):  
Trace Element ◽  
Continental Margin ◽  
South China ◽  
Volcanic Ash ◽  
Active Continental Margin ◽  
Main Body ◽  
Early Triassic ◽  
Late Permian ◽  
Triassic Boundary ◽  
Permian Triassic Boundary

AbstractPermian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.

scholarly journals Rebound from the Permian/Triassic mass extinction: evolutionary paleoecology of sequential early Triassic (Smithian to Spathian) marine paleocommunities

1992 ◽  
Vol 6 ◽  
pp. 261-261
Author(s):  
Jennifer K. Schubert ◽  
David J. Bottjer
Keyword(s):  
Mass Extinction ◽  
Lower Triassic ◽  
Upper Permian ◽  
Early Triassic ◽  
Triassic Boundary ◽  
Biotic Recovery ◽  
The Status ◽  
Life Habits ◽  
Stalked Crinoids ◽  
Permian Triassic Boundary

The Permian/Triassic mass extinction, the most devastating biotic crisis of the Phanerozoic, has aroused considerable scientific interest. However, because research has focused primarily on understanding the magnitude of diversity reduction and causal mechanisms, the nature and timing of biotic recovery in the Early Triassic are still poorly understood. Marine limestones in the Lower Triassic Moenkopi Formation, which disconformably overlies the Upper Permian of southeastern Nevada and southern Utah, provide a rare opportunity to study the aftermath of the mass extinction in shallow water carbonate environments.Two contemporaneous members of the Moenkopi record the first marine incursion from the northwest in the Early Triassic (Smithian), the very sparsely fossiliferous marginal marine Schnabkaib Member in Nevada and southwest Utah, and the Sinbad Limestone in central-southern Utah, a marine unit dominated by amalgamated and condensed fossil-rich beds. The Virgin Limestone member was deposited during a subsequent (Spathian) Early Triassic sea level rise, about 4-5 Ma following the Permian/Triassic boundary, and includes nearshore and inner shelf limestones characterized by fossiliferous storm beds.Because the fossiliferous limestones of the Smithian Sinbad and the Spathian Virgin were deposited in similar shallow subtidal settings, they provide an opportunity to compare and contrast the status of biotic rebound at different points along an Early Triassic “time transect.” Analysis of bulk samples reveals that the older Sinbad and younger Virgin are similar in each possessing 2-3 different benthic marine paleocommunities of low within-habitat species richness. There are, however, several important differences between the Sinbad and Virgin faunas. The richly fossiliferous Sinbad assemblages are primarily molluscan, composed of approximately 2-8 species of bivalves, which may or may not be accompanied by ammonoids and 0-11 species of gastropods. Small spines, possibly belonging to an echinoid, are numerous in some samples. Although bivalves are also abundant in Virgin Limestone assemblages, fossils of other higher taxa are well-represented, including abundant crinoid ossicles, common brachiopods, echinoid spines and plates, and rare ammonoids and gastropods. Sinbad faunas also appear to lack epibionts and borers, while they are present but not abundant in the Virgin.The addition from Sinbad to Virgin times of groups other than molluscs, with different life habits and strategies, most likely led to an increase in spatial partitioning and resource utilization, in particular the development of epifaunal tiering with the appearance of stalked crinoids in the Virgin. This pattern of earliest Triassic community dominance by molluscs followed by later more “Paleozoic-like” communities has been observed in other regions. Earliest Triassic paucity of epibionts and borers indicates significant reduction in the biotic component of taphonomic processes, including taphonomic feedback, when compared with other time intervals. Data from these Early Triassic assemblages thus indicate the initiation of both an evolutionary and an ecological rebound between Sinbad (Smithian) and Virgin (Spathian) times.

scholarly journals Archosauriform footprints in the Lower Triassic of Western Alps and their role in understanding the effects of the Permian-Triassic hyperthermal

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10522
Author(s):  
Fabio Massimo Petti ◽  
Heinz Furrer ◽  
Enrico Collo ◽  
Edoardo Martinetto ◽  
Massimo Bernardi ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Lower Triassic ◽  
Western Alps ◽  
Large Igneous Province ◽  
Early Triassic ◽  
Triassic Boundary ◽  
Habitable Zones ◽  
Single Well ◽  
Permian Mass Extinction ◽  
Permian Triassic Boundary

The most accepted killing model for the Permian-Triassic mass extinction (PTME) postulates that massive volcanic eruption (i.e., the Siberian Traps Large Igneous Province) led to geologically rapid global warming, acid rain and ocean anoxia. On land, habitable zones were drastically reduced, due to the combined effects of heating, drought and acid rains. This hyperthermal had severe effects also on the paleobiogeography of several groups of organisms. Among those, the tetrapods, whose geographical distribution across the end-Permian mass extinction (EPME) was the subject of controversy in a number of recent papers. We here describe and interpret a new Early Triassic (?Olenekian) archosauriform track assemblage from the Gardetta Plateau (Briançonnais, Western Alps, Italy) which, at the Permian-Triassic boundary, was placed at about 11° North. The tracks, both arranged in trackways and documented by single, well-preserved imprints, are assigned to Isochirotherium gardettensis ichnosp. nov., and are here interpreted as produced by a non-archosaurian archosauriform (erytrosuchid?) trackmaker. This new discovery provides further evidence for the presence of archosauriformes at low latitudes during the Early Triassic epoch, supporting a model in which the PTME did not completely vacate low-latitude lands from tetrapods that therefore would have been able to cope with the extreme hot temperatures of Pangaea mainland.

Marine Early Triassic Actinopterygii from the Candelaria Hills (Esmeralda County, Nevada, USA)

2019 ◽  
Vol 93 (5) ◽  
pp. 971-1000
Author(s):  
Carlo Romano ◽  
Adriana López-Arbarello ◽  
David Ware ◽  
James F. Jenks ◽  
Winand Brinkmann
Keyword(s):  
New Species ◽  
Mass Extinction ◽  
New Genus ◽  
Current Data ◽  
Early Triassic ◽  
Triassic Boundary ◽  
Bony Fishes ◽  
Mass Extinction Event ◽  
In The Beginning ◽  
Permian Triassic Boundary

AbstractA new locality for low-latitudinal, Early Triassic fishes was discovered in the Candelaria Hills, southwestern Nevada (USA). The fossils are derived from the lower Candelaria Formation, which was deposited during the middle–late Dienerian (late Induan), ca. 500 ka after the Permian-Triassic boundary mass extinction event. The articulated and disarticulated Osteichthyes (bony fishes), encompassing both Actinistia (coelacanths) and Actinopterygii (ray-fins), are preserved in large, silicified concretions that also contain rare coprolites. We describe the first actinopterygians from the Candelaria Hills. The specimens are referred toPteronisculus nevadanusnew species (Turseoidae?),Ardoreosomus occidentalisnew genus new species (Ptycholepidae), the stem neopterygianCandelarialepis argentusnew genus new species (Parasemionotidae), and Actinopterygii indet. representing additional taxa.Ardoreosomusn. gen. resembles other ptycholepids, but differs in its more angulate hyomandibula and lack of an elongate opercular process.Candelarialepisn. gen. is one of the largest parasemionotids, distinguished by its bipartite preopercle and scale ornamentation. Presented new species belong to genera (Pteronisculus) or families (Ptycholepidae, Parasemionotidae) that radiated globally after the mass extinction, thus underlining the striking similarities between Early Triassic (pre-Spathian) osteichthyan assemblages. The current data suggest that the diversity of low-latitudinal, Early Triassic bony fishes may have been greater than indicated thus far by the fossil record, probably due to sampling or taphonomic failure. All 24 fossils from the Candelaria Hills represent mid-sized or large osteichthyans, confirming the obvious absence of very small species (≤ 10 cm adult body length) in the beginning of the Mesozoic Era—even in low latitudes.UUID:http://zoobank.org/6a66ac96-d6b7-4617-94db-5a93cdb14215

A Permian Overtoniid Brachiopod in Early Triassic Sediments of Axel Heiberg Island, Canadian Arctic and its Implications on the Permian—Triassic Boundary

1972 ◽  
Vol 9 (5) ◽  
pp. 486-499 ◽  
Author(s):  
J. B. Waterhouse
Keyword(s):  
Canadian Arctic ◽  
Late Paleozoic ◽  
Ventral Valve ◽  
Early Triassic ◽  
Late Permian ◽  
Triassic Boundary ◽  
Axel Heiberg Island ◽  
Permian Triassic Boundary ◽  
Green Land

The ventral valve of an overtoniid productacean brachiopod generally thought to have been restricted to the late Paleozoic Era is described from the Blind Fiord Formation, Axel Heiberg Island, of Griesbachian (Early Triassic) age. It is not clear whether the specimen was derived from Permian rocks or was really of Griesbachian age. The latter appears likely from the fact that no similar specimens are known from underlying Permian. Genuine occurrences of Permian-type brachiopods in early Triassic rocks are rare. Half of the examples reported, from Armenia, Iran, and West Pakistan, are shown here to be dated erroneously, occurring in middle or late Permian rocks misdated as Triassic, Other examples, such as those from Green-land, are probably reworked because the Triassic beds conformably overlie mid-Permian rocks, and contain similar mid-Permian brachiopods, probably reworked from the underlying deposits.

Conodont zonation across the Permian–Triassic boundary at the Xiakou section, Yichang city, Hubei Province and its correlation with the Global Stratotype Section and Point of the PTB

2004 ◽  
Vol 41 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Wang Guoqing ◽  
Xia Wenchen
Keyword(s):  
High Precision ◽  
Early Triassic ◽  
Clay Layer ◽  
Late Permian ◽  
Yangtze Platform ◽  
Triassic Boundary ◽  
Conodont Zonation ◽  
Stratotype Section ◽  
Clay Layers ◽  
Permian Triassic Boundary

Xiakou section is situated north of the central Yangtze platform with successive Late Permian to Early Triassic strata, thicker than the Global Stratotype Section and Point (GSSP) of the Permian–Triassic boundary (PTB). We recognized three conodont zones across the PTB in this section by high-precision biostratigraphy. They are the Hindeodus latidentatus – Clarkina meishanensis Zone, Hindeodus parvus Zone, and Isarcicella isarcica Zone in ascending order, which correspond well with the GSSP. The present biostratigraphic work on Xiakou section certainly confirmed the conodont zonation through the PTB at the GSSP and also testified to the correctness of the PTB demarcation in Xiakou section. Based on this precise demarcation of the PTB, the appearance of a clay layer, bed ZSJI266, just beneath the PTB should be an important advantage over the GSSP, because this clay layer approaches to the PTB much in contrast with those two clay layers, bed 26 and bed 28, in the GSSP. Therefore, the radiometric isotopic dating in bed ZSJI266 at Xiakou section should give a more accurate age for the PTB.

scholarly journals Calibrating Mid-Permian to Early Triassic Khuff sequences with orbital clocks

GeoArabia ◽  
2010 ◽  
Vol 15 (3) ◽  
pp. 171-206 ◽  
Author(s):  
Moujahed I. Al-Husseini ◽  
Robley K. Matthews
Keyword(s):  
Time Scale ◽  
Radiometric Dating ◽  
Arabian Plate ◽  
Early Triassic ◽  
Geological Time ◽  
Triassic Boundary ◽  
Geological Time Scale ◽  
Type Section ◽  
Geologic Time Scale ◽  
Permian Triassic Boundary

ABSTRACT The Middle East Geologic Time Scale (ME GTS) seeks to document and age-calibrate Arabian Plate transgressive-regressive (T-R) depositional sequences using: (1) Geological Time Scale of the International Commission on Stratigraphy (GTS), and (2) Arabian Orbital Stratigraphy time scale (AROS). AROS is based on an orbital-forcing glacio-eustatic model that offers three orbital clocks to date T-R sequences: (1) Stratons @ ca. 405 Ky; (2) Dozons @ ca. 4.86 My (12 stratons); and Orbitons @ ca. 14.58 My (36 stratons, three dozons). The Earth today is in Orbiton 0, which started ca. 1.5 Ma (SB 0); the ages of lower boundaries of orbitons can be estimated with the formula SB n = n × 14.58 + 1.5 Ma. This scheme was used to calibrate the Arabian Plate’s Mid-Permian to Early Triassic Khuff sequences, which contain one of the largest gas-bearing carbonate reservoirs in the World. The Khuff and equivalent formations have been interpreted by several authors in terms of six long-period sequences in outcrop belts and subsurface sections (Khuff sequences KS6 to KS1 in ascending order). Their type sections are briefly reviewed with emphasis on their boundaries, higher-order architecture and stage assignments. The age calibration starts at the basal Khuff Sequence Boundary (Khuff SB, Sub-Khuff Unconformity) defined in a type section in Al Huqf outcrop in Oman. Above the Khuff SB (ca. 268.9 Ma) the type sections of the oldest Khuff sequences KS6 (ca. 268.9–264.0 Ma) and KS5 (ca. 264.0–259.1 Ma) are defined in Oman and interpreted to each consist of twelve subsequences (stratons) with the predicted architecture of two consecutive dozons. By biostratigraphy they span the Mid-Permian (Guadalupian Epoch), Wordian and Capitanian stages. Type-Sequence KS4 (ca. 259.1–254.2 Ma) is defined in Iran and corresponds to the Wuchiapingian Stage. The Iranian type-Khuff Sequence KS3 (ca. 254.2–249.4 Ma) contains nine subsequences (stratons) grouped between two major exposure surfaces. By correlation to the Changhsingian Stage and Permian/Triassic Boundary (PTrB) type section in South China, it is interpreted as a dozon with three missing stratons. Khuff Sequence KS2 (ca. 249.4–247.8 Ma) contains the PTrB with an orbital age of ca. 249.0 Ma, compared to 251.0 ± 0.4 in GTS and 249.0–253.0 Ma by radiometric dating in its type section. Khuff sequences KS2 and KS1 contain 13 subsequences (stratons) between ca. 249.4–244.1 Ma spanning latest Permian and Early Triassic. The boundary of the Khuff with the overlying Sudair Formation, Sudair Sequence Boundary, is defined in Borehole SHD-1 (Central Saudi Arabia) and calibrated at ca. 244.1 Ma falling near the age of the Early/Mid-Triassic Boundary in GTS. The enclosed Chart shows a work-in-progress correlation of the six Khuff sequences across the Arabian Plate.

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