THE GEOLOGICAL EVOLUTION OF THE SOUTHERN TAROOM TROUGH AND THE OVERLYING SURAT BASIN

1974 ◽  
Vol 14 (1) ◽  
pp. 50 ◽  
Author(s):  
N. F. Exon
Keyword(s):  
Late Jurassic ◽  
Lower Triassic ◽  
Stream Sediments ◽  
Lower Jurassic ◽  
Late Triassic ◽  
Upper Permian ◽  
Lower Permian ◽  
Early Triassic ◽  
The South ◽  
The North

Isopach, structure contour, and palaeo-geological maps illustrate the geological development of the southern Taroom Trough and the lower part of the Surat Basin sequence.The meridional southern Taroom Trough, 50,000 km2 in area, is a southerly subsurface extension of the outcropping Bowen Basin. It is fault-bounded to the east and plunges northward. The maximum thickness of sedimentary fill increases northward from less than 400 m to 10,000 m, and consists of Lower Permian marine sediments, Upper Permian coal measures, Lower Triassic redbeds, and Middle Triassic stream sediments. The trough's present western margin is depositional, but the faulted eastern margin started to form in the Late Permian in the south and in the Early Triassic in the north; movement ceased in the Early Triassic in the south and in the Late Triassic in the north. Tectonic movements did not recur until Late Jurassic time.Late Triassic erosion preceded deposition of Surat Basin sediments. These sediments extended over ever wider areas, even the basal sands spreading far beyond the Taroom Trough. The fully-developed Surat Basin is 300,000 km2 in area, and contains up to 2500 m of dominantly continental Jurassic sediments and dominantly marine Lower Cretaceous sediments. Lower Jurassic stream sediments (the main petroleum producers of the basin) are thickest and coarsest above the Taroom Trough, suggesting steady subsidence and compaction of the trough sediments.By the Late Jurassic this compaction had virtually ceased, and epeirogenic uplift had given the basin its present shape, with the Mimosa Syncline (above the Taroom Trough) and the south-westerly-trending Dirranbandi Syncline (above a basement depression) being major structural features.Petroleum, which is probably derived from both Permian and Jurassic sources, is most abundant in the Lower Jurassic sandstone on either side of the Mimosa Syncline. Some aspects of the migration and trapping of Permian petroleum are discussed, and it is suggested that the Lower Jurassic Hutton Sandstone in the virtually unexplored Bollon area could be prospective.

scholarly journals New biostratigraphic evidence of Late Permian to Late Triassic deposits from Central Tibet and their paleogeographic implications

Lithosphere ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 683-696 ◽  
Author(s):  
Gui-chun Wu ◽  
Zhan-sheng Ji ◽  
Wei-hua Liao ◽  
Jian-xin Yao
Keyword(s):  
Middle Triassic ◽  
Carbonate Platform ◽  
Lower Triassic ◽  
Upper Triassic ◽  
Suture Zone ◽  
Late Triassic ◽  
Upper Permian ◽  
Early Triassic ◽  
Late Permian ◽  
The North

Abstract Triassic deposits in the Bangong-Nujiang Suture Zone are important for understanding its tectonic nature and evolutionary history, but have not been systematically studied due to a lack of biostratigraphic data. For a long time, the Upper Triassic Quehala Group featuring clasolite has been regarded as the only rocky unit. In recent years, the silicite-dominated Gajia Formation that bears radiolarian fossils was suggested to represent Ladinian to Carnian deposits. The Upper Permian and Lower Triassic rocks have never been excavated and thus are considered to be absent. This research, however, reveals that fossils aged from the Late Permian to Anisian of the Middle Triassic and Norian of the Late Triassic have been preserved in the central Bangong-Nujiang Suture Zone, which provides evidence of Upper Permian to early Middle Triassic deposits and provides new insights on the Upper Triassic strata as well. A new Triassic strata succession is thus proposed for the Bangong-Nujiang Suture Zone, and it demonstrates great similarities with those from Lhasa to the south and Qiangtang to the north. Therefore, we deduce that the Bangong-Nujiang Suture Zone was under a similar depositional setting as its two adjacent terranes, and it was likely a carbonate platform background because limestones were predominant across the Triassic. The newly acquired biostratigraphic data indicate that Lhasa and Qiangtang could not have been located on two separate continents with disparate sedimentary settings; therefore, the Bangong-Nujiang Suture Zone likely did not represent a large ocean between them. This conclusion is supported by lithostratigraphic and paleomagnetic research, which revealed that Lhasa and Qiangtang were positioned at low to middle latitudes during the Early Triassic. Combining this conclusion with fossil evidence, we suggest that the three main Tibetan terranes were in the same palaeobiogeographic division with South China, at least during the Latest Permian to Early Triassic. The Early Triassic conodont species Pachycladina obliqua is probably a fossil sign of middle to low latitudes in palaeogeography.

scholarly journals New insights on the early Mesozoic evolution of multiple tectonic regimes in the northeastern North China Craton from the detrital zircon provenance of sedimentary strata

Solid Earth ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 1375-1397 ◽  
Author(s):  
Yi Ni Wang ◽  
Wen Liang Xu ◽  
Feng Wang ◽  
Xiao Bo Li
Keyword(s):  
North China Craton ◽  
North China ◽  
Early Jurassic ◽  
Orogenic Belt ◽  
Detrital Zircons ◽  
Late Triassic ◽  
Early Triassic ◽  
The South ◽  
The North ◽  
Early Mesozoic

Abstract. To investigate the timing of deposition and provenance of early Mesozoic strata in the northeastern North China Craton (NCC) and to understand the early Mesozoic paleotectonic evolution of the region, we combine stratigraphy, U–Pb zircon geochronology, and Hf isotopic analyses. Early Mesozoic strata include the Early Triassic Heisonggou, Late Triassic Changbai and Xiaoyingzi, and Early Jurassic Yihe formations. Detrital zircons in the Heisonggou Formation yield  ∼ 58 % Neoarchean to Paleoproterozoic ages and  ∼ 42 % Phanerozoic ages and were sourced from areas to the south and north of the basins within the NCC, respectively. This indicates that Early Triassic deposition was controlled primarily by the southward subduction of the Paleo-Asian oceanic plate beneath the NCC and collision between the NCC and the Yangtze Craton (YC). Approximately 88 % of the sediments within the Late Triassic Xiaoyingzi Formation were sourced from the NCC to the south, with the remaining  ∼ 12 % from the Xing'an–Mongolia Orogenic Belt (XMOB) to the north. This implies that Late Triassic deposition was related to the final closure of the Paleo-Asian Ocean during the Middle Triassic and the rapid exhumation of the Su–Lu Orogenic Belt between the NCC and YC. In contrast,  ∼ 88 % of sediments within the Early Jurassic Yihe Formation were sourced from the XMOB to the north, with the remaining  ∼ 12 % from the NCC to the south. We therefore infer that rapid uplift of the XMOB and the onset of the subduction of the Paleo-Pacific Plate beneath Eurasia occurred in the Early Jurassic.

THE TECTONIC ELEMENTS OF THE PERTH BASIN

1972 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
D.K. Jones ◽  
G.R. Pearson
Keyword(s):  
Lower Triassic ◽  
Upper Jurassic ◽  
Lower Jurassic ◽  
Tectonic Activity ◽  
Lower Permian ◽  
Fault Activity ◽  
The North ◽  
Basin Subsidence ◽  
Geophysical Surveys ◽  
Extreme North

Birth and growth of the highly faulted Perth Basin was dominated by the Darling Fault which down-throws an essentially elongate sedimentary trough against a Precambrian Shield to the east. The Precambrian Northampton and Leeuwin Blocks restrict the basin to the north and the south. The Perth Basin embraces four major sub- basins separated by intra-basin uplifts. These sub-basins are the Dandaragan and Sunbury Troughs and the Abrolhos and Vlaming Sub-basins. Major intra-basin uplifts include the Beagle, Turtle Dove and Harvey Ridges, and the Edwards Island Block.Surface outcrop is representative of only a small part of the total stratigraphic column. Deposition of Ordovician - Silurian sediments in only the extreme north of the basin was followed by a long period of non-deposition. Sedimentation recommenced in the Lower Permian and continued with minor breaks throughout the Mesozoic and into the Tertiary. The Permian had a widespread distribution, as did the Triassic and Jurassic which attained maximum thickness in the Dandaragan Trough. A major intra-Neocomian unconformity developed in the Vlaming Sub-basin where up to 20,000 ft. of pre-unconformity Neocomian and 5,000 ft. of post-unconformity marine Cretaceous sediments were deposited. Tertiary sediments were deposited in both the Vlaming and Abrolhos Sub-basins.Limited movement on the Darling Fault in Permian and Lower Triassic times led to gentle basin downwarp. Renewed fault activity in the Upper Triassic resulted in rapid basin subsidence, and less violent fault activity continued through the Lower Jurassic. The most severe tectonic activity and basin subsidence, with local uplift, occurred in the Upper Jurassic and Neocomian, at which time graben-collapse of a mid-basin arch offshore from Perth formed the Rottnest Trench. This intra-Neocomian tectonism was probably associated with .sea floor spreading, the westerly drift of India from Australia, and the break up of Gondwanaland.This structural synthesis of the Perth Basin is largely derived from geophysical surveys and deep drilling carried out over the past twenty-three years on the present leases of West Australian Petroleum Pty. Limited (WAPET).

scholarly journals New insights on the early Mesozoic evolution of multiple tectonic regimes in the northeastern North China Craton from the detrital zircon provenance of sedimentary strata

2018 ◽  
Author(s):  
Yi Ni Wang ◽  
Wen Liang Xu ◽  
Feng Wang ◽  
Xiao Bo Li
Keyword(s):  
Detrital Zircon ◽  
North China Craton ◽  
North China ◽  
Early Jurassic ◽  
Orogenic Belt ◽  
Late Triassic ◽  
Early Triassic ◽  
The South ◽  
The North ◽  
Early Mesozoic

Abstract. To investigate the timing of deposition and provenance of early Mesozoic strata in the northeastern North China Craton (NCC), and to reconstruct the early Mesozoic tectono-paleogeography of the region, we combine LA–ICP–MS detrital zircon U–Pb dating, Hf isotopic data. Early Mesozoic strata include the Early Triassic Heisonggou, Late Triassic Changbai and Xiaoyingzi, and Early Jurassic Yihe formations. Detrital zircons in the Heisonggou Formation comprise ~ 58 % Neoarchean to Paleoproterozoic and ~ 42 % Phanerozoic grains that were sourced from areas to the south and north of the basins within the NCC. This indicates that Early Triassic deposition was controlled primarily by southward subduction of the Paleo-Asian oceanic plate beneath the NCC, and collision between the NCC and the Yangtze Craton (YC). Approximately 88 % of sediments within the Late Triassic Xiaoyingzi Formation were sourced from the NCC to the south, with the remaining ~ 12 % from the Xing'an–Mongol Orogenic Belt (XMOB) to the north. This implies that Late Triassic deposition was related to the final closure of the Paleo-Asian Ocean during the Middle Triassic and the rapid exhumation of the Su–Lu Orogenic Belt between the NCC and YC. In contrast, ~ 88 % of sediments within the Early Jurassic Yihe Formation were sourced from the XMOB to the north, with the remaining ~ 12 % from the NCC to the south. We therefore infer that rapid uplift of the XMOB and the onset of subduction of the Paleo-Pacific Plate beneath Eurasia occurred in the Early Jurassic.

scholarly journals A review of Palaeozoic and Mesozoic tetrapods from Greenland

2018 ◽  
Vol 66 ◽  
pp. 21-46 ◽  
Author(s):  
Marco Marzola ◽  
Octávio Mateus ◽  
Jesper Milàn ◽  
Lars B. Clemmensen
Keyword(s):  
Late Jurassic ◽  
Early Jurassic ◽  
Late Carboniferous ◽  
Late Triassic ◽  
Late Devonian ◽  
Early Triassic ◽  
Shallow Marine ◽  
East Greenland ◽  
Marine Deposits ◽  
Theropod Dinosaurs

This article presents a synthesis of Palaeozoic and Mesozoic fossil tetrapods from Greenland, including an updated review of the holotypes and a new photographic record of the main specimens. All fossil tetrapods found are from East Greenland, with at least 30 different known taxa: five stem tetrapods (Acanthostega gunnari, Ichthyostega eigili, I. stensioi, I. watsoni, and Ymeria denticulata) from the Late Devonian of the Aina Dal and Britta Dal Formations; four temnospondyl amphibians (Aquiloniferus kochi, Selenocara groenlandica, Stoschiosaurus nielseni, and Tupilakosaurus heilmani) from the Early Triassic of the Wordie Creek Group; two temnospondyls (Cyclotosaurus naraserluki and Gerrothorax cf. pulcherrimus), one testudinatan (cf. Proganochelys), two stagonolepids (Aetosaurus ferratus and Paratypothorax andressorum), the eudimorphodontid Arcticodactylus, undetermined archosaurs (phytosaurs and both sauropodomorph and theropod dinosaurs), the cynodont Mitredon cromptoni, and three mammals (Haramiyavia clemmenseni, Kuehneotherium, and cf. ?Brachyzostrodon), from the Late Triassic of the Fleming Fjord Formation; one plesiosaur from the Early Jurassic of the Kap Stewart Formation; one plesiosaur and one ichthyosaur from the Late Jurassic of the Kap Leslie Formation, plus a previously unreported Late Jurassic plesiosaur from Kronprins Christian Land. Moreover, fossil tetrapod trackways are known from the Late Carboniferous (morphotype Limnopus) of the Mesters Vig Formation and at least four different morphologies (such as the crocodylomorph Brachychirotherium, the auropodomorph Eosauropus and Evazoum, and the theropodian Grallator) associated to archosaurian trackmakers are known from the Late Triassic of the Fleming Fjord Formation. The presence of rich fossiliferous tetrapod sites in East Greenland is linked to the presence of well-exposed continental and shallow marine deposits with most finds in terrestrial deposits from the Late Devonian and the Late Triassic.

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 Croonian lecture : The origin of mammals

1913 ◽  
Vol 87 (592) ◽  
pp. 87-88
Keyword(s):  
Single Case ◽  
Lower Jurassic ◽  
Upper Permian ◽  
Occipital Condyle ◽  
Steady Increase ◽  
Lower Permian ◽  
Secondary Palate ◽  
Middle And Upper Permian ◽  
Higher Types ◽  
Evolution Of Mammals

An endeavour is made to trace the evolution of mammals from Cotylosaurian ancestors through the carnivorous Therapsida. In Upper Carboniferous times the line probably passed through some primitive generalised Pelycosaurs; in Lower Permian through primitive, probably Therocephalian, Therapsids. In Middle and Upper Permian the line passed through the Gorgonopsia. In Triassic times the mammalian ancestors were small generalised Cynodonts. In Lower Jurassic the mammals are so Cynodont-like, and the Cynodonts so mammal-like, that in no single case are we absolutely certain which is which. In the Therocephalia, the Gorgonopsia, and the Cynodontia, the skull is very mammal-like. The zygomatic arch is, as in mammals, formed by the jugal and the squamosal. The teeth are divided into incisors, canines and molars. In the later Gorgonopsians there is an imperfect secondary palate; in Cynodonts a complete secondary palate as in mammals. In Permian Therapsids there is a single occipital condyle; in the Triassic Cynodonts there may he a single condyle slightly divided or two exoccipital condyles. There is, on passing from earlier to later types, a steady increase in the size of the dentary and decrease in the size of the other elements of the jaw. The quadrate also becomes much reduced in the higher types. In Gorgonopsians and probably all earlier types the arch of the atlas is a pair of bones; in Cynodonts, as in mammals, there is a single arch.

The systematic position of the Late Jurassic alleged dinosaur Macelognathus (Crocodylomorpha: Sphenosuchia)

2005 ◽  
Vol 42 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Ursula B Göhlich ◽  
Luis M Chiappe ◽  
James M Clark ◽  
Hans-Dieter Sues
Keyword(s):  
Late Jurassic ◽  
Upper Jurassic ◽  
Systematic Position ◽  
Lower Jurassic ◽  
Late Triassic ◽  
Morrison Formation ◽  
Postcranial Skeleton ◽  
Western Colorado ◽  
New Material ◽  
Limb Posture

Macelognathus vagans was described by O.C. Marsh in 1884, based on a mandibular symphysis from the Upper Jurassic Morrison Formation of Wyoming. Often considered a dinosaur but later tentatively referred to the Crocodylia, its phylogenetic identity has until now been enigmatic. New material of this species from the Morrison Formation of western Colorado demonstrates its affinities with basal crocodylomorphs commonly grouped together as the Sphenosuchia, which are characterized by a gracile postcranial skeleton with erect limb posture. Macelognathus shares features with Kayentasuchus from the Lower Jurassic Kayenta Formation of Arizona and Hallopus, which may be from the Morrison Formation of eastern Colorado. The new material constitutes the youngest definitive occurrence of a sphenosuchian, previously known from the Late Triassic to the Middle or Late? Jurassic.

THE DEPOSITIONAL HISTORY OF A PORTION OF THE NORTH PERTH BASIN—A SINGLE WELL DIPMETER ANALYSIS

1971 ◽  
Vol 11 (1) ◽  
pp. 90
Author(s):  
K. J. Bird ◽  
W. F. Coleman ◽  
H. Crocker
Keyword(s):  
First Generation ◽  
Source Area ◽  
Lower Triassic ◽  
Flood Plain ◽  
Upper Jurassic ◽  
Lower Jurassic ◽  
Depositional History ◽  
The North ◽  
Single Well ◽  
History Of

Four-arm dipmeter interpretation has been integrated with other wireline logs, lithologic and palaeontologic data, and regional geology to arrive at a history of the deposition in a portion of the North Perth Basin.The Permian sediments were deposited in a moderate to low energy, paralic to marine environment. They were unconformably overlain by a thin transgressive Lower Triassic sand and deepwater marine shale. The Middle Triassic sediments were deposited as a regressive marine sequence under the influence of a strong southwesterly uplift, and culminated in piedmont talus deposits of Upper Triassic age.In the Lower Jurassic this area evolved through a flood-plain environment to a paralic environment with a northeast-southwest oriented coastline and a northern source area. During the Middle Jurassic gentle crustal movements, coupled with an increasingly active northern and eastern source area, resulted in several cycles of nearshore deposition, and finally a marine transgression.Subsequent violent tectonic uplift to the east in the Upper Jurassic produced massive first generation sands which were deposited in a mainly continental environment.

Observations on the Lower Triassic petroleum prospectivity of the offshore Carnarvon and Roebuck basins

2016 ◽  
Vol 56 (1) ◽  
pp. 173 ◽  
Author(s):  
Stephen Molyneux ◽  
Jeff Goodall ◽  
Roisin McGee ◽  
George Mills ◽  
Birgitta Hartung-Kagi
Keyword(s):  
Regional Analysis ◽  
Lower Triassic ◽  
Source Rocks ◽  
Upper Permian ◽  
Regional Study ◽  
North West ◽  
Petroleum Systems ◽  
The North ◽  
Depositional Processes ◽  
Water Margin

Why are the only commercial hydrocarbon discoveries in Lower Triassic and Permian sediments of the western margin of Australia restricted to the Perth Basin and the Petrel Sub-basin? Recent regional analysis by Carnarvon Petroleum has sought to address some key questions about the Lower Triassic Locker Shale and Upper Permian Chinty and Kennedy formations petroleum systems along the shallow water margin of the Carnarvon and offshore Canning (Roebuck/Bedout) basins. This paper aims to address the following questions:Source: Is there evidence in the wells drilled to date of a working petroleum system tied to the Locker Shale or other pre-Jurassic source rocks? Reservoir: What is the palaeogeography and sedimentology of the stratigraphic units and what are the implications for the petroleum systems?The authors believed that a fresh look at the Lower Triassic to Upper Permian petroleum prospectivity of the North West Shelf would be beneficial, and key observations arising from the regional study undertaken are highlighted:Few wells along a 2,000 km area have drilled into Lower Triassic Locker Shale or older stratigraphy. Several of these wells have been geochemically and isotopically typed to potentially non Jurassic source rocks. The basal Triassic Hovea Member of the Kockatea Shale in the Perth Basin is a proven commercial oil source rock and a Hovea Member Equivalent has been identified through palynology and a distinctive sapropelic/algal kerogen facies in nearly 16 wells that penetrate the full Lower Triassic interval on the North West Shelf. Samples from the Upper Permian, the Hovea Member Equivalent and the Locker Shale have been analysed isotopically indicating –28, –34 and –30 delta C13 averages, respectively. Lower Triassic and Upper Permian reservoirs are often high net to gross sands with up to 1,000 mD permeability and around 20% porosity. Depositional processes are varied, from Locker Shale submarine canyon systems to a mixed carbonate clastic marine coastline/shelf of the Upper Permian Chinty and Kennedy formations.

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