A Kungurian Oceanic Upwelling on Yangtze Platform: Evidenced by δ^(13) C_(org) and Authigenic Silica in the Lower Chihsia Formation of Enshi Section in South China  

作　　者：Hao Yu Hengye Wei 

机构地区：[1]Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, Peking University [2]College of Earth Sciences East China Institute of Technology

出　　处：《Journal of Earth Science》2015年第2期211-218,共8页地球科学学刊（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 41302021);the Science and Technology Research Project of Jiangxi Province Education Department (No. GJJ13452);Research by Hao Yu is supported by the National Natural Science Foundation of China (No. 41290260);the Ministry of Education of China (No. 20120001110052)

摘　　要：The Late Paleozoic Ice Age across Carboniferous and Permian had a significant impact on the Kungurian （Upper Cisuralian series of Permian） Chihsia Formation in South China. This re- suited in a unique interval with features such as the lack of reef in Chihsian limestone, widespread stinkstone and nodular/bedded chert. The Chihsia limestone （Kungurian stage） deposited during a time of cooling was resulted from oceanic upwelling. Here we present evidence for this upwelling using sev- eral geochemical analyses： bulk organic carbon isotope, biomarker molecular geochemical data, and authigenic silica of the stinkstone member in the lower Chihsia Formation of the Kuangurian stage from the Enshi Section in western Hubei Province, South China. The lower part of the stinkstone member shows a rapid organic carbon isotope excursion with a -3%o shift triggered by the upwelling of 13C-depleted bottom water. The concurrent rapid increasing of authigenic silica content resulted from the enhanced supply of dissolved silica in the upwelling water mass. This upwelling at the Enshi Section also led to relative high TOC content, accounting for the widespread stinkstone in the lower Chihsia Formation during the Kungurian stage in Permian.The Late Paleozoic Ice Age across Carboniferous and Permian had a significant impact on the Kungurian （Upper Cisuralian series of Permian） Chihsia Formation in South China. This re- suited in a unique interval with features such as the lack of reef in Chihsian limestone, widespread stinkstone and nodular/bedded chert. The Chihsia limestone （Kungurian stage） deposited during a time of cooling was resulted from oceanic upwelling. Here we present evidence for this upwelling using sev- eral geochemical analyses： bulk organic carbon isotope, biomarker molecular geochemical data, and authigenic silica of the stinkstone member in the lower Chihsia Formation of the Kuangurian stage from the Enshi Section in western Hubei Province, South China. The lower part of the stinkstone member shows a rapid organic carbon isotope excursion with a -3%o shift triggered by the upwelling of 13C-depleted bottom water. The concurrent rapid increasing of authigenic silica content resulted from the enhanced supply of dissolved silica in the upwelling water mass. This upwelling at the Enshi Section also led to relative high TOC content, accounting for the widespread stinkstone in the lower Chihsia Formation during the Kungurian stage in Permian.

关 键 词：Chihsia Formation Enshi Section organic carbon isotope authigenic silica upwelling. 

分 类 号：P534.4[天文地球—古生物学与地层学]