Role of autochthonous versus detrital micrite in depositional geometries of Middle Triassic carbonate platform systems

2016 ◽  
Vol 128 (5-6) ◽  
pp. 989-999 ◽  
Author(s):  
Adriano Guido ◽  
A. Mastandrea ◽  
M. Stefani ◽  
F. Russo
Keyword(s):  
Middle Triassic ◽  
Carbonate Platform ◽  
Depositional Geometries

Early and Middle Triassic trends in diversity, evenness, and size of foraminifers on a carbonate platform in south China: implications for tempo and mode of biotic recovery from the end-Permian mass extinction

Paleobiology ◽  
2011 ◽  
Vol 37 (3) ◽  
pp. 409-425 ◽  
Author(s):  
Jonathan L. Payne ◽  
Mindi Summers ◽  
Brianna L. Rego ◽  
Demir Altiner ◽  
Jiayong Wei ◽  
...  
Keyword(s):  
South China ◽  
Mass Extinction ◽  
Evolutionary Dynamics ◽  
Middle Triassic ◽  
Carbonate Platform ◽  
Early Triassic ◽  
Data Set ◽  
Recovery Pattern ◽  
Biotic Recovery ◽  
Permian Mass Extinction

Delayed biotic recovery from the end-Permian mass extinction has long been interpreted to result from environmental inhibition. Recently, evidence of more rapid recovery has begun to emerge, suggesting the role of environmental inhibition was previously overestimated. However, there have been few high-resolution taxonomic and ecological studies spanning the full Early and Middle Triassic recovery interval, leaving the precise pattern of recovery and underlying mechanisms poorly constrained. In this study, we document Early and Middle Triassic trends in taxonomic diversity, assemblage evenness, and size distribution of benthic foraminifers on an exceptionally exposed carbonate platform in south China. We observe gradual increases in all metrics through Early Triassic and earliest Middle Triassic time, with stable values reached early in the Anisian. There is little support in our data set for a substantial Early Triassic lag interval during the recovery of foraminifers or for a stepwise recovery pattern. The recovery pattern of foraminifers on the GBG corresponds well with available global data for this taxon and appears to parallel that of many benthic invertebrate clades. Early Triassic diversity increase in foraminifers was more gradual than in ammonoids and conodonts. However, foraminifers continued to increase in diversity, size, and evenness into Middle Triassic time, whereas diversity of ammonoids and conodonts declined. These contrasts suggest decoupling of recovery between benthic and pelagic environments; it is unclear whether these discrepancies reflect inherent contrasts in their evolutionary dynamics or the differential impact of Early Triassic ocean anoxia or associated environmental parameters on benthic ecosystems.

scholarly journals A Middle Triassic pachypleurosaur (Diapsida: Eosauropterygia) from a restricted carbonate ramp in the Western Carpathians (Gutenstein Formation, Fatric Unit): paleogeographic implications

2018 ◽  
Vol 69 (1) ◽  
pp. 3-16 ◽  
Author(s):  
Andrej Čerňanský ◽  
Nicole Klein ◽  
Ján Soták ◽  
Mário Olšavský ◽  
Juraj Šurka ◽  
...  
Keyword(s):  
Middle Triassic ◽  
Carbonate Platform ◽  
Small Body ◽  
Western Carpathians ◽  
Subtidal Zone ◽  
Postcranial Skeleton ◽  
Tatra Mountains ◽  
Carbonate Ramps ◽  
Shallow Subtidal ◽  
Central Western Carpathians

AbstractAn eosauropterygian skeleton found in the Middle Triassic (upper Anisian) Gutenstein Formation of the Fatric Unit (Demänovská dolina Valley, Low Tatra Mountains, Slovakia) represents the earliest known occurrence of marine tetrapods in the Western Carpathians. The specimen represents a partly articulated portion of the postcranial skeleton (nine dorsal vertebrae, coracoid, ribs, gastral ribs, pelvic girdle, femur and one zeugopodial element). It is assigned to the Pachypleurosauria, more precisely to theSerpianosaurus–Neusticosaurusclade based on the following combination of features: (1) small body size; (2) morphology of vertebrae, ribs and femur; (3) tripartite gastral ribs; and (4) microanatomy of the femur as revealed by μCT. Members of this clade were described from the epicontinental Germanic Basin and the Alpine Triassic (now southern Germany, Switzerland, Italy), and possibly from Spain. This finding shows that pachypleurosaur reptiles attained a broader geographical distribution during the Middle Triassic, with their geographical range reaching to the Central Western Carpathians. Pachypleurosaurs are often found in sediments formed in shallow, hypersaline carbonate-platform environments. The specimen found here occurs in a succession with vermicular limestones in a shallow subtidal zone and stromatolitic limestones in a peritidal zone, indicating that pachypleurosaurs inhabited hypersaline, restricted carbonate ramps in the Western Carpathians.

scholarly journals Growth faults affecting depositional geometry, facies and sequence stratigraphy record on a carbonate platform edge (South Vercors Urgonian platform, SE France)

2019 ◽  
Vol 190 ◽  
pp. 1
Author(s):  
Serge Ferry ◽  
Danièle Grosheny
Keyword(s):  
Small Area ◽  
Carbonate Platform ◽  
Growth Fault ◽  
Sequence Stratigraphic ◽  
Fine Grained ◽  
Accommodation Space ◽  
Western Side ◽  
The Waves ◽  
Se France ◽  
Depositional Geometries

The first two calcarenite units at the base of the Urgonian limestones on the southern edge of the platform bear different depositional geometries depending on place (Cirque d’Archiane to Montagnette and Rocher de Combau). The lower calcarenite unit (Bi5 of Arnaud H. 1981. De la plate-forme urgonienne au bassin vocontien. Le Barrémo-Bédoulien des Alpes occidentales entre Isère et Buëch (Vercors méridional, Diois oriental et Dévoluy). Géologie Alpine, Grenoble, Mémoire 12: 3. Disponible sur https://tel.archives-ouvertes.fr/tel-00662966/document), is up to 200 m thick and shows three different patterns, in terms of accommodation space, from the western Archiane Cirque to the Montagnette to the east. On the western side of the Cirque, the unit begins on slope fine-grained limestone with thin sigmoïdal offlap geometry, suggesting little available space after a relative sea level fall. It is overlain by thick progradational/aggradational, then purely aggradational calcarenite capped by a coral and rudist-bearing bed. This bed is, therefore, interpreted as a maximum (although moderate) flooding facies. The depositional geometry is different on the eastern side of the Cirque, where a progradational pattern in the lower part of the unit is interrupted by a rotational movement affecting the depositional profile. The deformation promoted aggradation updip and retrogradation downdip as a result of starvation. The inferred growth fault updip (thought to be responsible for the change) began to function earlier at the Montagnette, explaining the huge calcarenite clinoforms found there, filling a deeper saddle created in the depositional profile. The same fault probably was reactivated later during the deposition of the overlying, thinner Bi6-1 unit, which appears at Rocher de Combau with an uncommon tidal facies at the base. A rotational bulge, created by the inferred growth fault, would have protected a small area behind it to spare the local calcarenite deposition from the waves for a while. These two examples show that sequence stratigraphic interpretation may differ from one place to the other, and even show opposite trends due to this kind of disturbance.

Middle Triassic carbonate-platform break-up and formation of small-scale half-grabens (Julian and Kamnik–Savinja Alps, Slovenia)

Facies ◽  
2012 ◽  
Vol 59 (3) ◽  
pp. 583-610 ◽  
Author(s):  
Bogomir Celarc ◽  
Špela Goričan ◽  
Tea Kolar-Jurkovšek
Keyword(s):  
Middle Triassic ◽  
Carbonate Platform ◽  
Small Scale ◽  
Break Up

Mega-shoaling in carbonate platform of the Middle Triassic Leikoupo Formation, Sichuan Basin, southwest China

2013 ◽  
Vol 57 (3) ◽  
pp. 465-479 ◽  
Author(s):  
XiuCheng Tan ◽  
Ling Li ◽  
Hong Liu ◽  
Jian Cao ◽  
XiaoQing Wu ◽  
...  
Keyword(s):  
Sichuan Basin ◽  
Southwest China ◽  
Middle Triassic ◽  
Carbonate Platform ◽  
Leikoupo Formation
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