Whole-rock geochemical variations and evolution of the arc-derived Murihiku Terrane, New Zealand

2002 ◽  
Vol 139 (6) ◽  
pp. 665-685 ◽  
Author(s):  
B. P. ROSER ◽  
D. S. COOMBS ◽  
R. J. KORSCH ◽  
J. D. CAMPBELL
Keyword(s):  
New Zealand ◽  
Continental Crust ◽  
Basaltic Andesite ◽  
Middle Triassic ◽  
Late Triassic ◽  
Late Permian ◽  
Rock Composition ◽  
Upper Continental Crust ◽  
Geochemical Parameters ◽  
Early Middle Triassic

Arc-flank volcaniclastic sedimentation in the Murihiku Terrane of New Zealand lasted about 120 million years from Late Permian to Early Cretaceous time. Despite the effects of pervasive zeolite-facies alteration, whole-rock geochemical parameters for sandstones, siltstones and tuffs record changes in source-rock composition, both in time and along the length of the depositional basin. Sandstones are considered to give a more reliable indication of the state of evolution of the source volcanic arc than do the siltstones. The siltstones commonly contain detrital white mica flakes that are generally lacking in the sandstones, and are possibly of distal continental origin. Some also contain very fine felsic ash particles. Average abundances and normalized multi-element diagrams are used to estimate proportions of three model end-member source constituents, average upper-continental crust (UCC), high-K rhyolite (RHY) and basaltic andesite (AND). Sandstone provenance for the Southland Syncline sector changed from a predominantly basaltic-andesite source in Late Permian to early Middle Triassic time, for example, UCC:RHY:AND = 0:17:83 in the Early to early Middle Triassic, to highly felsic in the Middle to Late Triassic, reaching UCC:RHY:AND = 2:74:24 in the Late Triassic Oretian Stage. A UCC component became increasing significant from latest Triassic upward and the proportion of mafic to felsic volcanism increased again, with UCC:RHY:AND = 15:30:35 in the Middle Jurassic Temaikan Stage. Mix modelling suggests that along-arc source proportions varied, with greater mafic and upper continental crust contributions in the northern Kawhia segment than in the Southland segment. These patterns may be explained by deposition at an oceanic Aleutian-type arc margin, with transition to a continental oceanic arc character induced either by arc evolution and dissection, forearc sliver translation, or underplating of rafted microcontinental fragments.

scholarly journals Comparative size evolution of marine clades from the Late Permian through Middle Triassic

Paleobiology ◽  
2015 ◽  
Vol 42 (1) ◽  
pp. 127-142 ◽  
Author(s):  
Ellen K. Schaal ◽  
Matthew E. Clapham ◽  
Brianna L. Rego ◽  
Steve C. Wang ◽  
Jonathan L. Payne
Keyword(s):  
Body Size ◽  
Middle Triassic ◽  
Size Reduction ◽  
Late Triassic ◽  
Early Triassic ◽  
Large Species ◽  
Late Permian ◽  
Triassic Boundary ◽  
Median Size ◽  
Permian Extinction

AbstractThe small size of Early Triassic marine organisms has important implications for the ecological and environmental pressures operating during and after the end-Permian mass extinction. However, this “Lilliput Effect” has only been documented quantitatively in a few invertebrate clades. Moreover, the discovery of Early Triassic gastropod specimens larger than any previously known has called the extent and duration of the Early Triassic size reduction into question. Here, we document and compare Permian-Triassic body size trends globally in eight marine clades (gastropods, bivalves, calcitic and phosphatic brachiopods, ammonoids, ostracods, conodonts, and foraminiferans). Our database contains maximum size measurements for 11,224 specimens and 2,743 species spanning the Late Permian through the Middle to Late Triassic. The Permian/Triassic boundary (PTB) shows more size reduction among species than any other interval. For most higher taxa, maximum and median size among species decreased dramatically from the latest Permian (Changhsingian) to the earliest Triassic (Induan), and then increased during Olenekian (late Early Triassic) and Anisian (early Middle Triassic) time. During the Induan, the only higher taxon much larger than its long-term mean size was the ammonoids; they increased significantly in median size across the PTB, a response perhaps related to their comparatively rapid diversity recovery after the end-Permian extinction. The loss of large species in multiple clades across the PTB resulted from both selective extinction of larger species and evolution of surviving lineages toward smaller sizes. The within-lineage component of size decrease suggests that only part of the size decrease can be related to the end-Permian kill mechanism; in addition, Early Triassic environmental conditions or ecological pressures must have continued to favor small body size as well. After the end-Permian extinction, size decrease occurred across ecologically and physiologically disparate clades, but this size reduction was limited to the first part of the Early Triassic (Induan). Nektonic habitat or physiological buffering capacity may explain the contrast of Early Triassic size increase and diversification in ammonoids versus size reduction and slow recovery in benthic clades.

Late Permian–early Middle Triassic back-arc basin development in West Qinling, China

2014 ◽  
Vol 87 ◽  
pp. 116-129 ◽  
Author(s):  
Lin Li ◽  
Qingren Meng ◽  
Alex Pullen ◽  
Carmala N. Garzione ◽  
Guoli Wu ◽  
...  
Keyword(s):  
Middle Triassic ◽  
Late Permian ◽  
West Qinling ◽  
Basin Development ◽  
Back Arc ◽  
Early Middle Triassic

SOUTH-WEST QUEENSLAND GAS — A RESOURCE FOR THE FUTURE

1987 ◽  
Vol 27 (1) ◽  
pp. 245
Author(s):  
J.L. Cosgrove
Keyword(s):  
Natural Gas ◽  
Success Rate ◽  
Middle Triassic ◽  
Low Risk ◽  
Late Permian ◽  
Early Permian ◽  
South West ◽  
Gas Potential ◽  
Early Middle Triassic ◽  
Very High

Natural gas has been discovered in 22 fields in the Central Eromanga and Cooper Basins of southwestern Queensland in the area comprised by ATP 259P. Proved, probable and possible reserves in excess of 36 × 109 m3 (1.27 TCF) are located in four discrete structural provinces. Fluvial sandstones of the Early Permian Patchawarra Formation and Late Permian Toolachee Formation contain the majority of the reserves. Minor amounts of gas are reservoired in the Early Permian Epsilon Formation, the Early-Middle Triassic Nappamerri Formation and the Early Jurassic Hutton Sandstone and Birkhead Formation. Considerable gas-liquids reserves are also found in these reservoirs.Existing reserves are located primarily in structural traps although lithofacies variations are widely recognised, particularly in the Patchawarra Formation, indicating both new play opportunities and difficulties in assessing the undiscovered gas potential of the permit. Additional gas potential is identified in flank areas of the more prominent structural axes such as the Jackson-Wackett-Innamincka Trend in fault-bounded, pinchout and sub-unconformity trapping configurations.More than 200 prospects and leads are identified with the potential to entrap approximately 51 × 109 m3 (1.80 TCF) of gas on an unrisked basis. When combined with reserves from established fields, the ultimate potential of the ATP is assessed as 87 × 109 m3 (8.10 TCF).Despite the very high success rate of previous exploration and appraisal programs, the ultimate gas potential of the Queensland portion of both the Cooper and Eromanga Basins has been only partially addressed. Exploration and appraisal programs providing future additions to proved and probable reserves are considered low risk and are dependent upon an agreement with the Queensland government that would enable the ATP holders to produce and sell gas interstate.

Permian–Triassic land-plant diversity in South China: Was there a mass extinction at the Permian/Triassic boundary?

Paleobiology ◽  
2011 ◽  
Vol 37 (1) ◽  
pp. 157-167 ◽  
Author(s):  
Conghui Xiong ◽  
Qi Wang
Keyword(s):  
South China ◽  
Mass Extinction ◽  
Middle Triassic ◽  
Land Plant ◽  
Land Plants ◽  
Late Triassic ◽  
Triassic Boundary ◽  
Permian Triassic Boundary ◽  
Diversity Dynamics ◽  
Early Middle Triassic

Diversity dynamics of the Permian–Triassic land plants in South China are studied by analyzing paleobotanical data. Our results indicate that the total diversity of land-plant megafossil genera and species across the Permian/Triassic boundary (PTB) of South China underwent a progressive decline from the early Late Permian (Wuchiapingian) to the Early-Middle Triassic. In contrast, the diversity of land-plant microfossil genera exhibited only a small fluctuation across the PTB of South China, showing an increase at the PTB. Overall, land plants across the PTB of South China show a greater stability in diversity dynamics than marine faunas. The highest extinction rate (90.91%) and the lowest origination rate (18.18%) of land-plant megafossil genera occurred at the early Early Triassic (Induan), but the temporal duration of the higher genus extinction rates (>60%) in land plants was about 23.4 Myr, from the Wuchiapingian to the early Middle Triassic (Anisian), which is longer than that of the coeval marine faunas (3–11 Myr). Moreover, the change of genus turnover rates in land-plant megafossils steadily fluctuated from the late Early Permian to the Late Triassic. More stable diversity and turnover rate as well as longer extinction duration suggest that land plants near the PTB of South China may have been involved in a gradual floral reorganization and evolutionary replacement rather than a mass extinction like those in the coeval marine faunas.

scholarly journals The early Triassic rhynchosaur Mesosuchus browni and the interrelationships of basal archosauromorph reptiles

1998 ◽  
Vol 353 (1368) ◽  
pp. 501-541 ◽  
Author(s):  
David W. Dilkes
Keyword(s):  
Middle Triassic ◽  
Sister Group ◽  
Recent Common Ancestor ◽  
Early Triassic ◽  
Late Permian ◽  
Assemblage Zone ◽  
Stratigraphic Ranges ◽  
Permian Mass Extinction ◽  
Fossil Records ◽  
Early Middle Triassic

Restudy of the unique diapsid reptile Mesosuchus browni Watson, from the Cynognathus Assemblage Zone (late Early Triassic to early Middle Triassic) of the Burgersdorp Formation (Tarkastad Subgroup; Beaufort Group) of South Africa, confirms that it is the most plesiomorphic known member of the Rhynchosauria. A new phylogenetic analysis of basal taxa of Archosauromorpha indicates that Choristodera falls outside of the Sauria, Prolacertiformes is a paraphyletic taxon with Prolacerta sharing a more recent common ancestor with Archosauriformes than with any other clade, Megalancosaurus and Drepanosaurus are sister taxa in the clade Drepanosauridae within Archosauromorpha, and are the sister group to the clade Tanystropheidae composed of Tanystropheus , Macrocnemus , and Langobardisaurus . Combination of the phylogenetic relationships of basal archosauromorphs and their known stratigraphic ranges reveals significant gaps in the fossil records of Late Permian and Triassic diapsids. Extensions of the temporal ranges of several lineages of diapsids into the Late Permian suggests that more groups of terrestrial reptiles survived the end-Permian mass extinction than thought previously.

scholarly journals The radiation of cynodonts and the ground plan of mammalian morphological diversity

2013 ◽  
Vol 280 (1769) ◽  
pp. 20131865 ◽  
Author(s):  
Marcello Ruta ◽  
Jennifer Botha-Brink ◽  
Stephen A. Mitchell ◽  
Michael J. Benton
Keyword(s):  
Middle Triassic ◽  
Morphological Diversity ◽  
Late Permian ◽  
Heterogeneous Distribution ◽  
Ground Plan ◽  
Extinction Event ◽  
The Mean ◽  
Mass Extinction Event ◽  
Early Middle Triassic ◽  
High Diversity

Cynodont therapsids diversified extensively after the Permo-Triassic mass extinction event, and gave rise to mammals in the Jurassic. We use an enlarged and revised dataset of discrete skeletal characters to build a new phylogeny for all main cynodont clades from the Late Permian to the Early Jurassic, and we analyse models of morphological diversification in the group. Basal taxa and epicynodonts are paraphyletic relative to eucynodonts, and the latter are divided into cynognathians and probainognathians, with tritylodonts and mammals forming sister groups. Disparity analyses reveal a heterogeneous distribution of cynodonts in a morphospace derived from cladistic characters. Pairwise morphological distances are weakly correlated with phylogenetic distances. Comparisons of disparity by groups and through time are non-significant, especially after the data are rarefied. A disparity peak occurs in the Early/Middle Triassic, after which period the mean disparity fluctuates little. Cynognathians were characterized by high evolutionary rates and high diversity early in their history, whereas probainognathian rates were low. Community structure may have been instrumental in imposing different rates on the two clades.

scholarly journals Geochemistry and Zircon U-Pb-Hf Isotopes of Metamorphic Rocks from the Kaiyuan and Hulan Tectonic Mélanges, NE China: Implications for the Tectonic Evolution of the Paleo-Asian and Mudanjiang Oceans

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 836
Author(s):  
Zuozhen Han ◽  
Jingjing Li ◽  
Zhigang Song ◽  
Guyao Liu ◽  
Wenjian Zhong ◽  
...  
Keyword(s):  
Tectonic Evolution ◽  
Middle Triassic ◽  
Late Triassic ◽  
Metamorphic Rocks ◽  
Late Permian ◽  
Early Permian ◽  
Ne China ◽  
The North ◽  
Tectonic Mélange ◽  
Final Closure

The Late Paleozoic–Early Mesozoic tectonic evolution of the Changchun-Yanji suture (CYS) was mainly associated with the Paleo-Asian and Mudanjiang tectonic regimes. However, the spatial and temporal overprinting and variations of these two regimes remains are still dispute. In order to evaluate this issue, in this contribution, we present new zircon U-Pb ages and a whole-rock geochemical and zircon Hf isotopic dataset on a suite of metamorphic rocks, including gneisses, actinolite schist, leptynites, and biotite schists, from tectonic mélanges in northern Liaoning and central Jilin provinces, NE China. Based on zircon LA-ICP-MS U-Pb dating results, protoliths show wide ranges of aging spectrum, including Paleoproterozoic (2441 Ma), Early Permian (281 Ma), Late Permian (254 Ma), and Late Triassic (230 Ma). The Permian protoliths of leptynites from the Hulan Tectonic Mélange (HLTM) and gneisses from the Kaiyuan Tectonic Mélange (KYTM) exhibit arc-related geochemical signatures, implying that the Paleo-Asian Ocean (PAO) did not close prior to the Late Permian. The Late Triassic protoliths of gneisses from the KYTM, in combination with previously reported coeval igneous rocks along the CYS, comprises a typical bimodal igneous suite in an E–W-trending belt, suggesting a post-orogenic extensional environment. Consequently, we infer that the final closure of the PAO took place during the Early–Middle Triassic. The Early Permian protoliths of biotite schists from the HLTM are alkali basaltic rocks and contain multiple older inherited zircons, which, in conjunction with the geochemical features of the rocks, indicate that they were generated in a continental rift related to the initial opening of the Mudanjiang Ocean (MO). Data from this contribution and previous studies lead us to conclude that the MO probably opened during the Middle Triassic, due to the north–south trending compression caused by the final closure of the PAO.

scholarly journals Macroevolutionary patterns in the evolutionary radiation of archosaurs (Tetrapoda: Diapsida)

2010 ◽  
Vol 101 (3-4) ◽  
pp. 367-382 ◽  
Author(s):  
Stephen L. Brusatte ◽  
Michael J. Benton ◽  
Graeme T. Lloyd ◽  
Marcello Ruta ◽  
Steve C. Wang
Keyword(s):  
Strong Evidence ◽  
Fossil Record ◽  
Morphological Character ◽  
Middle Triassic ◽  
Early Jurassic ◽  
Late Triassic ◽  
Morphological Disparity ◽  
Faunal Abundance ◽  
Evolutionary Radiation ◽  
Early Middle Triassic

ABSTRACTThe rise of archosaurs during the Triassic and Early Jurassic has been treated as a classic example of an evolutionary radiation in the fossil record. This paper reviews published studies and provides new data on archosaur lineage origination, diversity and lineage evolution, morphological disparity, rates of morphological character change, and faunal abundance during the Triassic–Early Jurassic. The fundamental archosaur lineages originated early in the Triassic, in concert with the highest rates of character change. Disparity and diversity peaked later, during the Norian, but the most significant increase in disparity occurred before maximum diversity. Archosaurs were rare components of Early–Middle Triassic faunas, but were more abundant in the Late Triassic and pre-eminent globally by the Early Jurassic. The archosaur radiation was a drawn-out event and major components such as diversity and abundance were discordant from each other. Crurotarsans (crocodile-line archosaurs) were more disparate, diverse, and abundant than avemetatarsalians (bird-line archosaurs, including dinosaurs) during the Late Triassic, but these roles were reversed in the Early Jurassic. There is no strong evidence that dinosaurs outcompeted or gradually eclipsed crurotarsans during the Late Triassic. Instead, crurotarsan diversity decreased precipitously by the end-Triassic extinction, which helped usher in the age of dinosaurian dominance.

scholarly journals Feroxichthys panzhouensis sp. nov., a hump-backed colobodontid (Neopterygii, Actinopterygii) from the early Middle Triassic of Panzhou, Guizhou, China

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11257
Author(s):  
Xin-Ying Ma ◽  
Guang-Hui Xu ◽  
Bing-He Geng
Keyword(s):  
New Species ◽  
South China ◽  
Middle Triassic ◽  
Cladistic Analysis ◽  
Marine Ecosystems ◽  
Late Triassic ◽  
Diagnostic Features ◽  
Body Form ◽  
Similar Body ◽  
Early Middle Triassic

Neopterygii is a taxonomically diverse clade of ray-finned fishes, including Teleostei, Holostei and closely related fossil taxa. The Colobodontidae is a stem group of large-sized neopterygians with a durophagous feeding adaption from the Middle to Late Triassic marine ecosystems in Europe and South China. Here, we report the discovery of a new colobodontid, Feroxichthys panzhouensis sp. nov., based on a well-preserved specimen from the early Middle Triassic (Anisian) of Panzhou (formerly known as Panxian), Guizhou, China. The discovery extends the geographical distribution of Feroxichthys from eastern Yunnan into western Guizhou, and demonstrates a more rapid diversification of early colobodontids than previously thought. The new species possesses diagnostic features of Feroxichthys (e.g., a fused lacrimal-maxilla), but it is easily distinguished from the type species Feroxichthys yunnanensis and other colobodontids by some derived features on the skull and, especially, the relatively short and deep body with a prominent postcranial hump. This body form, previously unknown in colobodontids, implicates a morphological adaptation to structurally complex habitats in light of ecological studies of modern ray-finned fishes with a similar body form. In addition, the feeding apparatus suggests a more obligate durophagous diet for F. panzhouensis sp. nov. than other colobodontids. Results of a cladistic analysis recover the new species as a sister taxon of F. yunnanensis within the Colobodontidae, and suggest that a hump-backed body form has independently evolved multiple times in Triassic neopterygians. As such, the new finding provides an important addition for our understanding of the morphological and ecological diversity of neopterygian fishes from the Triassic marine ecosystems in South China.

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