钙同位素地球化学研究进展  

Advance in calcium isotope geochemistry

作　　者：李亮[1] 蒋少涌[1] 

机构地区：[1]南京大学地球科学系成矿作用国家重点实验室,江苏南京210093

出　　处：《中国地质》2008年第6期1088-1100,共13页Geology in China

基　　金：国家自然科学基金委员会优秀创新群体基金(40221301)资助

摘　　要：钙同位素是非传统稳定同位素,近年来已成为国际同位素地球化学领域的研究热点。钙同位素测定采用TIMS或MC-ICP-MS,并表示为δ44/40Ca或δ44/42Ca。自然界的δ44/40Ca变化范围从-2.0‰到2.0‰,仅跨越4.0‰。虽然动力学分馏与平衡分馏假说能各自解释一些分馏现象,但钙同位素分馏机理仍不清晰,值得进一步研究。目前钙同位素的地质应用集中于以下方面:(1)根据有孔虫G.sacculifer的钙同位素组成重建古海洋温度;(2)海洋中钙的地球化学循环;(3)利用海水[Ca2+]评估大气pCO2。Calcium isotope, one of non-traditional stable isotopes, has been a research hotspot in isotope geochemistry field since the last decade. Calcium isotope ratios are widely measured by TIMS or MC-ICP-MS, and are expressed as （δ^44/40Ca or δ^44/42Ca respectively. Variations of δ^44/40Ca in nature are mainly from -2.0‰ to 2.0‰, spanning only a limited range of 4.0‰. The hypotheses of kinetic and equilibrium fractionation can interpret some of calcium isotope fractionation observations, but more work is needed to better understand the fractionation.mechanism. Up to now the geological application of calcium isotope includes： （1）Paleoceanography temperature reconstruction based on δ^44/40Ca of planktonic foraminifera G. sacculifer; （2） Geochemical cycling of calcium in ocean; （3）Estimation ofpCO2 in terms of seawater calcium concentration.

关 键 词：钙同位素 分馏机理 G.sacculifer 

分 类 号：P595[天文地球—地球化学]