(古)盐度研究的一种重要工具——锶同位素  

STRONTIUM AS AN ESSENTIAL INDICATOR OF PALEOSALINITY

作　　者：刘秀明[1] 王世杰[1] 孙承兴[1] 贾玉鹤[1] 黎廷宇[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002

出　　处：《矿物学报》2000年第1期91-96,共6页Acta Mineralogica Sinica

基　　金：国家自然科学基金!(批准号 :49673 2 0 1)资助

摘　　要：本文详细地阐述了海水 陆表水双元体系中锶同位素的混合原理、混合水体中87Sr/ 86Sr值与盐度的定量关系。利用Sr同位素不随生物、化学作用过程发生分馏作用及Sr与Ca化学性质相似等特征 ,地层、沉积物中生物壳体和碳酸盐岩87Sr/ 86Sr值可作为沉积水体 (古 )盐度确定的一种有用工具。文中详细地综述了国内外在这方面的研究进展 ,并讨论了成岩后生作用对生物壳体和碳酸盐岩87Sr/ 86Sr原始值的影响作用 。Large variations in strontium concentrations exist between seawater (8×10 -6 ) and freshwater (<1×10 -6 ), the strontium isotopic ratios of freshwater are either higher or lower than global seawater values and there is a simple mixing relationship between the two. Furthermore, organic shell and carbonate, with no vital effect, are the ideal paleoenvironment proxies. This paper reviews the hyperbolic relationship between 87 Sr/ 86 Sr and salinity, and the progress in the application of strontium isotopes of the shell and carbonate as a key tool to determine salinity (paleosalinity). Meanwhile, the effects of diagenic alteration on primary 87 Sr/ 86 Sr values for the shell and carbonate are also discussed. In short, the method is useful and reliable to reconstruct the paleoenvironment and quantify the paleosalinity and its change in the transition facies.

关 键 词：锶同位素 古盐度 古环境 生物壳体 碳酸盐岩 

分 类 号：P531[天文地球—古生物学与地层学]