海洋地质与第四纪地质2025，Vol.45Issue(6)：173-180,8.DOI:10.16562/j.cnki.0256-1492.2025041201
西藏申扎地区下二叠统冷泉碳酸盐岩的地球化学特征
Geochemical characteristics of Lower Permian cold seep carbonate rocks in Xainza,Xizang(Tibet),China
摘要
Abstract
Cold seep carbonates are one of the most important products of cold seep fluid activity.Their geochemical information is of great significance for revealing the evolution of cold seep systems,the source of fluids,and the redox environment when cold seep carbonates were formed.Taking the paleo-cold seep carbonates of the Lower Permian in Xainza,Xizang(Tibet),SW China as the research object,we explored their fluid sources and sedimentary environments in petrology,mineralogy,carbon and oxygen isotopes,and rare earth element geochemistry.Results show that the cold seep carbonates in the region are mainly calcite,whose δ13C values ranged from-19.6‰ to-17.5‰,and δ18O values from-9.2‰ to-7.2‰,indicating that the carbon source of the cold seep carbonates was mainly from thermogenic methane and was also affected by the mixing of a small amount of seawater.The rare earth element distribution pattern shows a"bell-shaped"feature with a slight anomaly of Ce,indicating that the cold seep carbonates were deposited in a weakly oxidizing or reducing environment.关键词
冷泉碳酸盐岩/流体来源/氧化还原环境/二叠纪/西藏申扎Key words
cold seep carbonate/fluid source/redox environment/the Permian Period/Xainza Xizang(Tibet)分类
天文与地球科学引用本文复制引用
JIANG Yunyang,WANG Qinxian,ZHAO Ruosi,CHEN Duofu..西藏申扎地区下二叠统冷泉碳酸盐岩的地球化学特征[J].海洋地质与第四纪地质,2025,45(6):173-180,8.基金项目
国家自然科学基金面上项目"海底原油冷泉系统的原油厌氧氧化生物降解过程的代谢途径:来自原油冷泉碳酸盐岩中的晶格硫酸盐的多硫及氧同位素的制约"(42172110) （42172110）
