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

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.

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Mercury evidence from the Sino-Korean block for Emeishan volcanism during the Capitanian mass extinction

Geological Magazine ◽

10.1017/s0016756818000481 ◽

2018 ◽

Vol 156 (06) ◽

pp. 1105-1110 ◽

Cited By ~ 5

Author(s):

HYOSANG KWON ◽

MUN GI KIM ◽

YONG IL LEE

Keyword(s):

Organic Carbon ◽

Mass Extinction ◽

Volcanic Eruptions ◽

Global Carbon Cycle ◽

Upper Permian ◽

South China Block ◽

Extinction Event ◽

Tethys Ocean ◽

Mass Extinction Event ◽

Global Carbon

AbstractA prominent large negative δ13Corg excursion and a coeval notable spike in mercury (Hg)/total organic carbon ratio are observed in the middle–upper Permian Gohan Formation in central Korea, located in the eastern Sino-Korean block (SKB), which may represent the Capitanian mass extinction event. The SKB was separated from the South China block by the eastern Palaeo-Tethys Ocean. This finding from the SKB supports the widespread Hg loading to the environment emitted from the Emeishan volcanic eruptions in SW China. This study demonstrates that the Hg cycle was globally perturbed in association with global carbon cycle perturbation that occurred during the Capitanian Extinction.

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Climate modelling of mass-extinction events: a review

International Journal of Astrobiology ◽

10.1017/s1473550409990061 ◽

2009 ◽

Vol 8 (3) ◽

pp. 207-212 ◽

Cited By ~ 4

Author(s):

Georg Feulner

Keyword(s):

Mass Extinction ◽

Plate Tectonics ◽

Large Scale ◽

Volcanic Eruptions ◽

Biological Species ◽

Future Research ◽

Climate Modelling ◽

Mass Extinctions ◽

Extinction Events ◽

Mass Extinction Events

AbstractDespite tremendous interest in the topic and decades of research, the origins of the major losses of biodiversity in the history of life on Earth remain elusive. A variety of possible causes for these mass-extinction events have been investigated, including impacts of asteroids or comets, large-scale volcanic eruptions, effects from changes in the distribution of continents caused by plate tectonics, and biological factors, to name but a few. Many of these suggested drivers involve or indeed require changes of Earth's climate, which then affect the biosphere of our planet, causing a global reduction in the diversity of biological species. It can be argued, therefore, that a detailed understanding of these climatic variations and their effects on ecosystems are prerequisites for a solution to the enigma of biological extinctions. Apart from investigations of the paleoclimate data of the time periods of mass extinctions, climate-modelling experiments should be able to shed some light on these dramatic events. Somewhat surprisingly, however, only a few comprehensive modelling studies of the climate changes associated with extinction events have been undertaken. These studies will be reviewed in this paper. Furthermore, the role of modelling in extinction research in general and suggestions for future research are discussed.

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Limits to biodiversity cycles from a unified model of mass-extinction events

International Journal of Astrobiology ◽

10.1017/s1473550410000455 ◽

2011 ◽

Vol 10 (2) ◽

pp. 123-129 ◽

Cited By ~ 12

Author(s):

Georg Feulner

Keyword(s):

Mass Extinction ◽

Volcanic Eruptions ◽

Unified Model ◽

Point Of View ◽

Theoretical Point ◽

Mass Extinctions ◽

Evolution Of Life ◽

Empirical Point ◽

Extinction Events ◽

Life On Earth

AbstractEpisodes of species mass extinction dramatically affected the evolution of life on Earth, but their causes remain a source of debate. Even more controversy surrounds the hypothesis of periodicity in the fossil record, with conflicting views still being published in the scientific literature, often even based on the same state-of-the-art datasets. From an empirical point of view, limitations of the currently available data on extinctions and possible causes remain an important issue. From a theoretical point of view, it is likely that a focus on single extinction causes and strong periodic forcings has strongly contributed to this controversy. Here I show that if there is a periodic extinction signal at all, it is much more likely to result from a combination of a comparatively weak periodic cause and various random factors. Tests of this unified model of mass extinctions on the available data show that the model is formally better than a model with random extinction causes only. However, the contribution of the periodic component is small compared to factors such as impacts or volcanic eruptions.

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Evidence for photic zone euxinia through the end-Permian mass extinction in the Panthalassic Ocean (Peace River Basin, Western Canada)

Palaeoworld ◽

10.1016/j.palwor.2007.05.008 ◽

2007 ◽

Vol 16 (1-3) ◽

pp. 39-50 ◽

Cited By ~ 64

Author(s):

Lindsay E. Hays ◽

Tyler Beatty ◽

Charles M. Henderson ◽

Gordon D. Love ◽

Roger E. Summons

Keyword(s):

River Basin ◽

Mass Extinction ◽

Western Canada ◽

Photic Zone ◽

Peace River ◽

Permian Mass Extinction

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Fire and the Coming of the Modern World

Burning Planet ◽

10.1093/oso/9780198734840.003.0009 ◽

2018 ◽

Author(s):

Andrew C. Scott

Keyword(s):

Mass Extinction ◽

Atmospheric Oxygen ◽

Late Eocene ◽

Modern World ◽

Early Eocene ◽

Earth System ◽

Fundamental Change ◽

Oxygen Level ◽

The Usa ◽

Permian Mass Extinction

What kind of world dawned after the K/P boundary? We know from studies across localities in the USA that there is evidence of frequent wildfires continuing into the earliest Paleogene. But what happened to the atmospheric oxygen level after recovery from the K/P mass extinction—did it remain above modern levels? Were we still in a high-fire world? If there were fires, what is the evidence in the charcoal record, and do we know anything about the vegetation that was burning? When the charcoal in the coal database was originally compiled, one of the important issues was how we recorded and represented our data. Early to mid-Paleocene Epoch coals (from around 65 to 55 million years ago) are often recorded as ‘earliest Tertiary’ in coal literature. (The Tertiary was the name we used to use for what we now call the Paleogene and Neogene Periods, stretching from around 65 to 1 million years ago.) However, coals that are nearer to the start of the Eocene Epoch, just older than 55 million years ago, are notoriously difficult to date. This is a problem we have with many coal sequences, as they are deposited on land, and most of the fossils used to give ages are found in marine waters. Many coals of this age are often simply recorded as coming from the late Paleocene or early Eocene. Where we have good dating information, Paleocene coals all tend to have high inertinite (charcoal) contents, well above 19 per cent. By the mid to late Eocene (50–40 million years ago), however, worldwide the charcoal contents are low, around 5 per cent or even less. There must, therefore, have been a fundamental change in the Earth system at this time. Another problem is the way in which we chose to represent our data and show the calculated oxygen curve. In order to get sufficient data to plot the curves we decided to use 10-millionyear bins. This was not a problem for the Paleozoic–Mesozoic transition, covering the great Permian mass extinction, which took place 250 million years ago.

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