Mo isotopes in the Lower Cambrian formation of southern China and its implications on paleo-ocean environment  

作　　者：WEN HanJie ZHANG YuXu FAN HaiFeng HU RuiZhong 

机构地区：[1]State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China [2]Graduate University of Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Science Bulletin》2009年第24期4756-4762,共7页

基　　金：Supported by the National Basic Research Program of China (Grant No. 2007 CB411402);National Natural Science Foundation of China (Grant Nos. 40773034 and 40873014);"West Light" of the Chinese Academy of Sciences,and Opening Foun-dation of State Key Laboratory of Continental Dynamics (Northwest University)

摘　　要：Over the past decade, as one of nontraditional stable isotopes, Mo isotope has developed rapidly and now become an important geochemical proxy to trace paleo-oceanic and atmospheric evolution through geological history. In this paper, Early Cambrian formations in southern China are investigated. The results indicate that δ 97/95Mo values of Early Cambrian seawater may have been larger than 1.4‰, values that are close to those of the modern ocean. It was also found that the variations in Mo isotope composition in samples from two sections (Huangjiawan and Gezhongwu in Guizhou) were closely related to changes in redox conditions during sedimentary processes. Combining our results with existing data, a preliminary model for the evolution of seawater Mo isotope composition through geological history was provided. It indicated that Mo isotopic variations were generally consistent with the evolution of atmospheric oxygen.Over the past decade, as one of nontraditional stable isotopes, Mo isotope has developed rapidly and now become an important geochemical proxy to trace paleo-oceanic and atmospheric evolution through geological history. In this paper, Early Cambrian formations in southern China are investigated. The results indicate that δ 97/95Mo values of Early Cambrian seawater may have been larger than 1.4‰, values that are close to those of the modern ocean. It was also found that the variations in Mo isotope composition in samples from two sections （Huangjiawan and Gezhongwu in Guizhou） were closely related to changes in redox conditions during sedimentary processes. Combining our results with existing data, a preliminary model for the evolution of seawater Mo isotope composition through geological history was provided. It indicated that Mo isotopic variations were generally consistent with the evolution of atmospheric oxygen.

关 键 词：稳定同位素 海洋环境 中国南部 下寒武统 钼 同位素组成 南方 氧化还原条件 

分 类 号：P597.2[天文地球—地球化学] X55[天文地球—地质学]