Showing papers by "Sonja Lojen published in 1999"
TL;DR: In this paper, the decomposition of sedimentary organic matter and methane formation in a eutrophic dimictic subalpine lake Lake Bled was investigated by measurement of in situ concentrations of dissolved inorganic carbon DIC in the pore water and its stable carbon isotopic composition, as well as by incubation experiments.
31 citations
TL;DR: A number of possible explanations for the extinction of life have been proposed, such as volcanic activity, sea-level fluctuation, changes in sea-water chemistry, an extra-terrestrial impact event and various related factors as mentioned in this paper.
Abstract: Permo-Triassic (P/Tr) boundary events, which took place approximately 250 Ma ago, led to the most extensive mass extinction in the history of life. A number of possible explanations for this profound break in the evolution of life have been proposed, such as volcanic activity, sea-level fluctuation, changes in sea-water chemistry, an extra-terrestrial impact event and various related factors (YOICHI, 1994). The most recently proposed cause of the mass extinction at the end of the Permian is a combination of these more or less co-occurring events operating in three phases (ERVIN, 1996). The first began with the marine regression during the Late Permian and resulted in the destruction of many marine basins, reduction in the habitat area of many organisms and increased climatic instability. The second phase involved the eruption of the Siberian Traps and further environmental degradation. The final phase may have started immediately prior to the boundary when the Late Permian regression ended and the earliest Triassic transgression begun. The global events outlined above coincide with isotope and elemental anomalies recorded in several P/ Tr boundary sections all
13 citations