Expanded Analysis of Catastrophic Soil Erosion during the End-Permian Biotic Crisis

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Expanded Analysis of Catastrophic Soil Erosion during the End-Permian Biotic Crisis

Scientists have come to many conclusions in explaining the mass extinction of the end-Permian era, and Mark Sephton and his geological team have contributed greatly to the understanding and explanation of the cause of the biotic crisis.  After doing organic geochemical analyses of organic matter in northern Italy, Sephton et al. have discovered the DNA (polysaccharides) of land based organisms in sedimentary rock dating from the marine Permian-Triassic transition period. It was after studying these polysaccharides Sephton et al. hypothesized that within the Permian-Triassic transition there were volcanic eruptions which caused disruption of atmospheric chemistry, leading to the death of land vegetation which began to collect in excess and which finally resulted in a gigantic soil-erosion into the oceans which killed Permian marine life by hypoxia and anoxia.

In Val Badia in northern Italy, Sephton et al. collected sedimentary rock samples dating back to the end-Permian era and ran tests trying to detect any organic-geochemical evidence of terrestrial ecosystem collapse. This was tested by determining if the sediments had been deposited in shallow marine environments which had taken an input of major land-plant debris at anytime. The organic compounds and carbon isotopes compounds were confirmed by Sephton et al. using high-resolution gas chromatography – mass spectrometry. The organic soil matter was specifically furan structures which are produced by the dehydration of cellulose and, when found in fossilized organic matter, which are usually presumed to be the remains of dehydrated polysaccharides. This DNA implied that the initial soil conditions were very good for burying and preserving eroded organic soil matter in the marine ecosystem.

To further support the hypothesis of the end-Permian Soil Crisis, Sephton et al. needed evidence of excessive soil erosion from other land masses that had been a part of the single land mass of Pangaea. Hence the reference from Retallack, (2005) of pedoliths or re-deposited soils found in Antarctica, eastern Australia, and South Africa, as this similar evidence affirms the validity of Sephton’s et al. hypothesis and throws doubt on the idea that it was merely an isolated incident in northern Italy.  While geochemical and geophysical data have been used in the past to provide an  explanation for the huge Permian extinction, believed to be the result of a meteorite impact similar to that of the dinosaur extinction of the Cretaceous-Tertiary boundary, the question still remains as to what acted as the catalyst for the cascade of volcanic eruptions. While a large enough meteorite impact to the Earth could have set the stage for this tectonic work to occur, both Sephton et al. and other members of the larger scientific community at large refute such an impact as being solely responsible for the mass extinction. Koeberl et al., who are cited within Sephton’s article, conducted similar sedimentary chemical analysis and also suggest that a geochemical event of a volcanogenic disturbance greatly altered atmospheric chemistry.

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Evidence shows volcanic activity specifically occurred within the Siberian Traps. In fact, Benton, MJ (2007) cited Sephton et al. argues that the massive eruptions released excessive amounts of carbon dioxide and the atmospheric acidification change caused acid rain which killed plants and led to stripping of soils. This is most likely the cause of the widespread end-Permian soil erosion according to a fellow field scientists Visscher et al., (1996) and Maruoka et al., (2003). The soil stability and soil samples showing reduced bacteria content and decreased polysaccharide decomposition rates was most likely the result of the acidification. The volcanic emissions ...

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