现代地质2016，Vol.30Issue(2)：420-425,6.
西藏申扎早二叠世碳酸盐岩的极低碳稳定同位素及其冷泉指示意义
Extremely 13 C-depleted Carbonate Indicating Cold Seepage in Early Permian from Xainza,Tibet
摘要
Abstract
Extremely 1 3 C-depleted isotope is the key evidence to identify ancient cold seepage and methane re-lease event in Earth history.There has been no report of direct evidence of cold seepage in Early Permian period so far.Here we unprecedentedly present the carbonate carbon and oxygen isotopes with extreme 1 3 C depletion in Early Permian of Lasha Block,Tibet.The negative correlation of carbon and oxygen isotopes is pronounced and the lowest carbon isotope is to -34.69‰(VPDB),exclusively indicating anaerobic oxidation of methane. These carbonates occur in the upper member of the Lanfjie Formation in Xainza,Tibet as carbonate lens and carbonate-cemented concretion,and calcite crystal fans are more depleted in 1 3 C than carbonate cements in the concretions.We infer the occurrence of ancient cold seepage in Early Permian in the study area and attribute this event to the postglacial destabilization of gas hydrate reservoir.This study is significant to investigate glac-ioeustatic change,oceanographic geochemistry,paleoecology and climate change.关键词
西藏申扎/早二叠世/碳酸盐岩/极低碳稳定同位素Key words
Xainza,Tibet/Early Permian/carbonate/extremely 1 3 C-depleted isotope分类
天文与地球科学引用本文复制引用
安显银,张予杰,朱同兴..西藏申扎早二叠世碳酸盐岩的极低碳稳定同位素及其冷泉指示意义[J].现代地质,2016,30(2):420-425,6.基金项目
中国地质调查局项目（1212011121257）。 （）
