Carbon isotope excursions across the Permian-Triassic boundary in the Meishan section, Zhejiang Province, China  

作　　者：Changqun Cao Wei Wang Yugan Jin 

机构地区：[1]Chinese Acad Sci, Nanjing Inst Geol & Palaeontol, Nanjing 210008, Peoples R China

出　　处：《Chinese Science Bulletin》2002年第13期1125-1129,共5页

基　　金：This work was supported by the Major Basic Research Projects of the Ministry of Science ; Technology of China (Grant No. G2000077700); Opening Laboratory of Palaeobiology and Stratigraphy of Nanjing Institute of Geology and Palaeontology, the Chinese

摘　　要：Both gradual and sharp decrease in organic and carbonate carbon isotope values were detected across the Permian-Triassic boundary in the Meishan section, Changxing, Zhejiang Province, China. The gradual decrease in organic carbon isotope values started at the bottom of Bed 23, coinciding with the strong oscillations of total organic carbon (TOC) contents, indicates increasing fluxes from carbonate to organic carbon reservoir during this interval. A 2.3‰ sharp drop of inorganic carbon isotope values occurred at the uppermost part of Bed 24e. A 3.7‰ sharp drop of organic carbon isotope values occurred in Bed 26. The dramatic drop of inorganic carbon isotope value of 8‰ reported previously is not confirmed from the unweathered carbonate samples in Bed 27. The large-scale fluctuation of organic carbon isotope values in the Yinkeng Formation reflects different extent of mixing of marine and terrestrial organic matters. The gradual depletion and subsequent sharp drop of carbon isotopes near theBoth gradual and sharp decrease in organic and carbonate carbon isotope values were detected across the Permian-Triassic boundary in the Meishan section, Changxing, Zhejiang Province, China. The gradual decrease in organic carbon isotope values started at the bottom of Bed 23, coinciding with the strong oscillations of total organic carbon (TOC) contents, indicates increasing fluxes from carbonate to organic carbon reservoir during this interval. A 2.3‰ sharp drop of inorganic carbon isotope values occurred at the uppermost part of Bed 24e. A 3.7‰ sharp drop of organic carbon isotope values occurred in Bed 26. The dramatic drop of inorganic carbon isotope value of 8‰ reported previously is not confirmed from the unweathered carbonate samples in Bed 27. The large-scale fluctuation of organic carbon isotope values in the Yinkeng Formation reflects different extent of mixing of marine and terrestrial organic matters. The gradual depletion and subsequent sharp drop of carbon isotopes near the Permian-Triassic boundary might indicate complex causes of the end-Permian mass extinction.

关 键 词：MEISHAN section PERMIAN-TRIASSIC BOUNDARY carbon ISOTOPE mass extinction. 

分 类 号：P595[天文地球—地球化学]