Carbon and oxygen isotopes suggesting deep-water basin deposition associated with hydrothermal events(Shangsi Section, Northwest Sichuan Basin-South China)  

作　　者：CHEN Hui XIE Xi'nong MAO Kainan HUANG Junhua 

机构地区：[1]Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, Faculty of Resources, China University of Geosciences [2]State Key Laboratory of Geological Processes and Mineral Resources,Faculty of Geosciences,China University of Geosciences

出　　处：《Chinese Journal Of Geochemistry》2014年第1期77-85,共9页中国地球化学学报

基　　金：financially supported by the Key Project of the Natural Science Foundation of Hubei Province (2008CDA095);the SINOPEC project (G0800-06-ZS-319)

摘　　要：Carbon and oxygen isotope records for Shangsi Section in Northwest Sichuan Basin, South China can help investigating depositional environments and processes, including the burial rate and possible contribution of hydrothermal events. Samples from the lower Chihsian Formation show δ13CPDB and δ18OPDB values close to those of typical marine limestone. However, the overlying Permian middle-upper Chihsian, Wujiaping, and Maokou Formation samples reveal negative δ18OSMOW values and strong positive δ13CPDB values. These indicate high biological productivity and rapid burial of organic carbon. Samples from the Dalong Formation present both negative δ13CPDB and negative δ18OPDB values, which are quite different from the underlying Permian strata. These abnormal carbon and oxygen isotope characteristics in the Dalong Formation may suggest that hydrothermal processes contributed to deposition.Carbon and oxygen isotope records for Shangsi Section in Northwest Sichuan Basin, South China can help investigating depositional environments and processes, including the burial rate and possible contribution of hydrotherrnal events. Samples from the lower Chihsian Formation show δl3CPDB and δ18OPDB values close to those of typical marine limestone. However, the overlying Permian middle-upper Chihsian, Wujiaping, and Maokou Forma- tion samples reveal negative δ^18OSMow values and strong positive δ^13CpoB values. These indicate high biological productivity and rapid burial of organic carbon. Samples from the Dalong Formation present both negative δ13CPDR and negative δ18OpDB values, which are quite different from the underlying Permian strata. These abnormal carbon and oxygen isotope characteristics in the Dalong Formation may suggest that hydrothermal processes contributed to deposition.

关 键 词：氧同位素记录 盆地沉积 四川盆地 有机碳 西北部 热液活动 中国 二叠纪地层 

分 类 号：P618.13[天文地球—矿床学]