scholarly journals Different triggers for the two pulses of mass extinction across the Permian and Triassic boundary

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guoshan Li ◽  
Wei Liao ◽  
Sheng Li ◽  
Yongbiao Wang ◽  
Zhongping Lai
Keyword(s):  
Mass Extinction ◽  
Temporal Dynamics ◽  
Oxygen Deficiency ◽  
Marine Ecosystem ◽  
Volcanic Eruptions ◽  
Ecosystem Change ◽  
Triassic Boundary ◽  
Low Diversity ◽  
Micritic Limestone ◽  
Fossil Records

AbstractWidespread ocean anoxia has been proposed to cause biotic mass extinction across the Permian–Triassic (P–Tr) boundary. However, its temporal dynamics during this crisis period are unclear. The Liangfengya section in the South China Block contains continuous marine sedimentary and fossil records. Two pulses of biotic extinction and two mass extinction horizons (MEH 1 & 2) near the P–Tr boundary were identified and defined based on lithology and fossils from the section. The data showed that the two pulses of extinction have different environmental triggers. The first pulse occurred during the latest Permian, characterized by disappearance of algae, large foraminifers, and fusulinids. Approaching the MEH 1, multiple layers of volcanic clay and yellowish micritic limestone occurred, suggesting intense volcanic eruptions and terrigenous influx. The second pulse occurred in the earliest Triassic, characterized by opportunist-dominated communities of low diversity and high abundance, and resulted in a structural marine ecosystem change. The oxygen deficiency inferred by pyrite framboid data is associated with biotic declines above the MEH 2, suggesting that the anoxia plays an important role.

scholarly journals Sedimentary factories and ecosystem change across the Permian-Triassic Critical Interval (P-TrCI) – insights from the Xiakou area (South China)

2020 ◽  
Author(s):  
Yu Pei ◽  
Jan-Peter Duda ◽  
Joachim Reitner
Keyword(s):  
South China ◽  
Mass Extinction ◽  
Oxygen Depletion ◽  
Ecosystem Change ◽  
Critical Interval ◽  
Triassic Boundary ◽  
Carbonate Production ◽  
Carbonate Formation ◽  
Carbonate Factory ◽  
Permian Triassic Boundary

AbstractThe Permian-Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian-Triassic Critical Interval (P-TrCI) in the Xiakou area (South China). Six microfacies (MF) were classified. The succession begins with a eukaryote-controlled carbonate factory (MF-1) that passes upward into an organomineralization-dominated carbonate factory (MF-2–3). Organic-rich marls atop these units reflect carbonate factory collapse (MF-4). Organomineralization-driven carbonate formation restarts prior to the Permian-Triassic boundary (MF-5) and subsequently develops into a mixed carbonate factory where organomineralization and biomineralization are almost equally important (MF-6). MF-1 reflects oxygenated shallow water environments. In contrast, MF-2–6 were all deposited in somewhat deeper environments, some of which episodically exhibited elevated salinities, oxygen depletion, and, possibly, euxinic conditions. Our results demonstrate that distinct changes in carbonate production styles, biodiversity, and environmental conditions are not synchronous at Xiakou. Furthermore, the Xiakou record is strikingly different to that of other localities, even from the same area (e.g., the Global Stratotype Section and Point section at Meishan). Together, these findings highlight the enormous complexity of the P-TrCI and calls simplified views of the Permian-Triassic mass extinction into question.

The Permo-Triassic transition in Spitsbergen: δ13Corg chemostratigraphy, Fe and S geochemistry, facies, fauna and trace fossils

1998 ◽  
Vol 135 (1) ◽  
pp. 47-62 ◽  
Author(s):  
P. B. WIGNALL ◽  
R. MORANTE ◽  
R. NEWTON
Keyword(s):  
Water Column ◽  
Mass Extinction ◽  
Marine Ecosystem ◽  
Trace Fossil ◽  
Lower Latitude ◽  
Early Triassic ◽  
Late Permian ◽  
Ecosystem Recovery ◽  
Triassic Boundary ◽  
Field Evidence

New δ13Corg analyses of two boundary sections between the late Permian Kapp Starostin Formation and the early Triassic Vardebukta Formation of western Spitsbergen confirm field evidence that their contact is a conformable one. Thus, contrary to previous reports, some Spitsbergen sections contain a complete record of the environmental and faunal changes during the crisis interval of the end Permian mass extinction. No environmental deterioration is recorded in the late Permian until near the end of the terminal Changxingian Stage, whereupon the abundant siliceous sponge fauna of the Kapp Starostin Formation disappears along with the deep-burrowing fauna responsible for the Zoophycus trace fossil. A low diversity dysaerobic trace fossil assemblage is briefly developed before a transition to finely laminated, pyritic facies immediately beneath the Permo-Triassic boundary. Analysis of the S/C ratios from the laminated strata suggests that free H2S was present in the water column (euxinic conditions) even in relatively nearshore settings subject to storm sandstone deposition. The mass extinction crisis in Spitsbergen is therefore coincident with the extensive development of oxygen-poor conditions in the water column and compares closely, both in timing and nature, with the crisis seen in lower latitude Tethyan settings. However, the subsequent aftermath and recovery in the Boreal sections of Spitsbergen was more rapid than in Tethys. Thus, a shoreface sandstone body within the Dienerian Stage contains an appreciable diversity of fauna (by the standards of the early Triassic), including bryozoans, calcareous algae and deep infaunal bivalves, that suggests the marine ecosystem recovery began earliest in higher palaeolatitudes.

scholarly journals Sedimentary factories and ecosystem change across the Permian–Triassic Critical Interval (P–TrCI): insights from the Xiakou area (South China)

PalZ ◽  
2020 ◽  
Author(s):  
Yu Pei ◽  
Jan-Peter Duda ◽  
Joachim Reitner
Keyword(s):  
South China ◽  
Mass Extinction ◽  
Oxygen Depletion ◽  
Ecosystem Change ◽  
Critical Interval ◽  
Triassic Boundary ◽  
Carbonate Production ◽  
Carbonate Formation ◽  
Carbonate Factory ◽  
Permian Triassic Boundary

Abstract The Permian–Triassic mass extinction included a potentially catastrophic decline of biodiversity, but ecosystem change across this event remains poorly characterized. Here we reconstruct sedimentary factories and ecosystem change across the Permian–Triassic Critical Interval (P–TrCI) in the Xiakou area (South China). Six microfacies (MF) were classified. The succession begins with a eukaryote-controlled carbonate factory (MF-1) that passes upward into an organomineralization-dominated carbonate factory (MF-2–3). Organic-rich marls atop these units reflect carbonate factory collapse (MF-4). Organomineralization-driven carbonate formation restarts prior to the Permian–Triassic boundary (MF-5) and subsequently develops into a mixed carbonate factory where organomineralization and biomineralization are almost equally important (MF-6). MF-1 reflects oxygenated shallow water environments. In contrast, MF-2–6 were all deposited in somewhat deeper environments, some of which episodically exhibited elevated salinities, oxygen depletion, and, possibly, euxinic conditions. Our results demonstrate that distinct changes in carbonate production styles, biodiversity, and environmental conditions are not synchronous at Xiakou. Furthermore, the Xiakou record is strikingly different to that of other localities, even from the same area (e.g., the Global Stratotype Section and Point section at Meishan). Together, these findings highlight the enormous complexity of the P–TrCI and calls simplified views of the Permian–Triassic mass extinction into question.

Spatial and temporal dynamics of Pacific capelin Mallotus catervarius in the Gulf of Alaska: implications for ecosystem-based fisheries management

2020 ◽  
Vol 637 ◽  
pp. 117-140 ◽  
Author(s):  
DW McGowan ◽  
ED Goldstein ◽  
ML Arimitsu ◽  
AL Deary ◽  
O Ormseth ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Marine Ecosystem ◽  
Gulf Of Alaska ◽  
Data Series ◽  
Limited Information ◽  
Important Species ◽  
Multiple Data ◽  
Spatial And Temporal Dynamics ◽  
Spawning Areas ◽  
Spatio Temporal

Pacific capelin Mallotus catervarius are planktivorous small pelagic fish that serve an intermediate trophic role in marine food webs. Due to the lack of a directed fishery or monitoring of capelin in the Northeast Pacific, limited information is available on their distribution and abundance, and how spatio-temporal fluctuations in capelin density affect their availability as prey. To provide information on life history, spatial patterns, and population dynamics of capelin in the Gulf of Alaska (GOA), we modeled distributions of spawning habitat and larval dispersal, and synthesized spatially indexed data from multiple independent sources from 1996 to 2016. Potential capelin spawning areas were broadly distributed across the GOA. Models of larval drift show the GOA’s advective circulation patterns disperse capelin larvae over the continental shelf and upper slope, indicating potential connections between spawning areas and observed offshore distributions that are influenced by the location and timing of spawning. Spatial overlap in composite distributions of larval and age-1+ fish was used to identify core areas where capelin consistently occur and concentrate. Capelin primarily occupy shelf waters near the Kodiak Archipelago, and are patchily distributed across the GOA shelf and inshore waters. Interannual variations in abundance along with spatio-temporal differences in density indicate that the availability of capelin to predators and monitoring surveys is highly variable in the GOA. We demonstrate that the limitations of individual data series can be compensated for by integrating multiple data sources to monitor fluctuations in distributions and abundance trends of an ecologically important species across a large marine ecosystem.

Hirnantia Fauna from the Condroz Inlier, Belgium: another case of a relict Ordovician shelly fauna in the Silurian?

2021 ◽  
pp. 1-27
Author(s):  
Sofia Pereira ◽  
Jorge Colmenar ◽  
Jan Mortier ◽  
Jan Vanmeirhaeghe ◽  
Jacques Verniers ◽  
...  
Keyword(s):  
Sea Level ◽  
Mass Extinction ◽  
Late Ordovician ◽  
Lake District ◽  
Low Diversity ◽  
Hirnantia Fauna ◽  
And Sea Level

Abstract The end-Ordovician mass extinction, linked to a major glaciation, led to deep changes in Hirnantian–Rhuddanian biotas. The Hirnantia Fauna, the first of two Hirnantian survival brachiopod-dominated communities, characterizes the lower–mid Hirnantian deposits globally, and its distribution is essential to understand how the extinction took place. In this paper, we describe, illustrate, and discuss the first macrofossiliferous Hirnantia Fauna assemblage from Belgium, occurring in the Tihange Member of the Fosses Formation at Tihange (Huy), within the Central Condroz Inlier. Six fossiliferous beds have yielded a low-diversity, brachiopod-dominated association. In addition to the brachiopods (Eostropheodonta hirnantensis, Plectothyrella crassicosta, Hirnantia sp., and Trucizetina? sp.), one trilobite (Mucronaspis sp.), four pelmatozoans (Xenocrinus sp., Cyclocharax [col.] paucicrenulatus, Conspectocrinus [col.] celticus, and Pentagonocyclicus [col.] sp.), three graptolites (Cystograptus ancestralis, Normalograptus normalis, and ?Metabolograptus sp.), together with indeterminate machaeridians and bryozoans were identified. The graptolite assemblage, from the Akidograptus ascensus-Parakidograptus acuminatus Biozone, indicates an early Rhuddanian (Silurian) age, and thus, an unexpectedly late occurrence of a typical Hirnantia Fauna. This Belgian association may represent an additional example of relict Hirnantia Fauna in the Silurian, sharing characteristics with the only other known from Rhuddanian rocks at Yewdale Beck (Lake District, England), although reworking has not been completely ruled out. The survival of these Hirnantian taxa into the Silurian might be linked to delayed post-glacial effects of rising temperature and sea-level, which may have favored the establishment of refugia in these two particular regions that were paleogeographically close during the Late Ordovician–early Silurian.

scholarly journals A three-dimensional view on biodiversity changes: spatial, temporal, and functional perspectives on fish communities in the Baltic Sea

2018 ◽  
Vol 75 (7) ◽  
pp. 2463-2475 ◽  
Author(s):  
Romain Frelat ◽  
Alessandro Orio ◽  
Michele Casini ◽  
Andreas Lehmann ◽  
Bastien Mérigot ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
Temporal Dynamics ◽  
Marine Ecosystem ◽  
Fish Communities ◽  
The Baltic Sea ◽  
Functional Richness ◽  
Holistic Understanding ◽  
The Baltic

Abstract Fisheries and marine ecosystem-based management requires a holistic understanding of the dynamics of fish communities and their responses to changes in environmental conditions. Environmental conditions can simultaneously shape the spatial distribution and the temporal dynamics of a population, which together can trigger changes in the functional structure of communities. Here, we developed a comprehensive framework based on complementary multivariate statistical methodologies to simultaneously investigate the effects of environmental conditions on the spatial, temporal and functional dynamics of species assemblages. The framework is tested using survey data collected during more than 4000 fisheries hauls over the Baltic Sea between 2001 and 2016. The approach revealed the Baltic fish community to be structured into three sub-assemblages along a strong and temporally stable salinity gradient decreasing from West to the East. Additionally, we highlight a mismatch between species and functional richness associated with a lower functional redundancy in the Baltic Proper compared with other sub-areas, suggesting an ecosystem more susceptible to external pressures. Based on a large dataset of community data analysed in an innovative and comprehensive way, we could disentangle the effects of environmental changes on the structure of biotic communities—key information for the management and conservation of ecosystems.

scholarly journals A Little-Known Mass Extinction and the “Dawn of the Modern World”

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Scott Norris
Keyword(s):  
Mass Extinction ◽  
Volcanic Eruptions ◽  
Modern World ◽  
Western Canada

Volcanic eruptions in what is now western Canada may have triggered a million years of rain and a mass extinction that launched the reign of the dinosaurs.

scholarly journals Siberian Trap volcanism, global warming and the Permian-Triassic mass extinction: New insights from Armenian Permian-Triassic sections: Comment

2021 ◽  
Author(s):  
Micha Horacek ◽  
Leopold Krystyn ◽  
Aymon Baud
Keyword(s):  
Global Warming ◽  
Mass Extinction ◽  
Seawater Temperature ◽  
Correct Position ◽  
Triassic Boundary ◽  
Temperature Changes ◽  
Siberian Trap ◽  
Stratotype Section ◽  
Permian Triassic Boundary

Joachimski et al. carried out geochemical investigations to study seawater temperature changes and their potential triggers across the Permian-Triassic Boundary (PTB). Unfortunately, in our opinion, an incorrect biochronology was applied to define the PTB, and the existing alternative was not considered, nor the reasoning explained. As a consequence, Joachimski et al. report diachronous temperature changes for the investigated Chanakhchi section with respect to the global stratotype section and point (GSSP) in Meishan, China. This discrepancy disappears when the, in our view, correct position of the PTB is adopted by using the proper biochronology.

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