Lower Triassic Inorganic Carbon Isotope Excursion in Chaohu, Anhui Province, China

摘要

This paper reports a Lower Triassic inorganic carbon isotope profile from the North Ping-dingshan Section in Chaohu, Anhui Province, China, which was situated in a deep part of the Lower Yangtze carbonate ramp. The δ(~(13)C) excursion shows two periods from the Permian-Triassic boundary to the lower Spathian substage, corresponding to the ecosystem undergoing evolution and recovery after the end-Permian mass extinction and related events. The first period starts at the δ(~(13)C) depletion caused by the mass extinction and evolves with a gradual δ(~(13)C) increase resulting from the development of some disaster taxa during the Induan. The strong Smithian δ(~(13)C) depletion in the second period might be formed by the collapse of the disaster ecosystem and the biotic recovery occurred with the explosive increase of bioproductivity in the Spathian. Thus the δ(~(13)C) excursion in the Lower Triassic expresses patterns of biotic evolution and recovery during the erratic ecosystem that followed the great end-Permian mass extinction.