洞穴次生化学沉积物中Mg、Sr、Ca及其比值的环境指代意义  

THE RATIOS OF Mg/Ca,Mg/Sr IN THE SPELEOTHEMS AND THEIR ENVIRONMENTAL MEANINGS IN GUILIN AREA

作　　者：李彬[1] 袁道先[1] 林玉石[1] 李红春[2] 覃嘉铭[1] 

机构地区：[1]中国地质科学院岩溶地质研究所,桂林541004 [2]美国南加州大学,ca900890740

出　　处：《中国岩溶》2000年第2期115-122,共8页Carsologica Sinica

基　　金：国家自然科学基金项目(49632100);原地矿部"九五"重要基础理论项目(9501104)资助;岩溶动力学开放研究实验室资助项目

摘　　要：通过桂林地区盘龙洞 1号石笋和丰鱼岩 4号石笋的 Ca、Mg、Sr及其比值的研究 ,并通过与氧同位素记录的对比分析 ,初步认为洞穴次生化学沉积物中的 Sr、Mg、Ca及其比值的形成既取决于环境温度的变化 ,又取决于水文条件的变化。当大气环流系统未发生显著变化时 ,岩溶水文地质条件较相似 ,这时 ,Mg/ Ca和 Mg/ Sr比值的变化主要取决于环境温度的变化 ;而当大气环流系统发生显著变化时 (如出现冰期和间冰期的显著变化 ) ,Mg/ Ca和 Mg/ Sr比值则主要取决于水文地质条件 ,即降水条件的变化。尽管在一定的条件下利用 Mg、Sr、Ca指标可以获得很高分辨率的信息 ,但由于 Mg、 Sr、 Ca地球化学习性的复杂性 ,以及其影响因素的多元化 ,这种指标作为单独指标应用就会十分危险。WT5BZ]Based on the studies of the Ca, Mg, Sr contents and their ratios in the speleothems from Panlong cave and Fengyu cave in Guilin area, it could be concluded that the contents of Ca, Mg, Sr and their ratio characteristics depend on not only the changes of environmental temperature, but also hydrological conditions. When the atmospheric circulation keeps in a relatively stable pattern, and the hydrogeological conditions are similar, the changes of Mg/Ca, Mg/Sr ratios are mainly controlled by the environmental temperature; when the atmospheric circulation greatly changes (e.g. from glacial stage to interglacial stage), the Mg/Ca, Mg/Sr ratios are mainly controlled by the hydrological conditions. Although they could be used as the proxies to study environmental changes, it should be very careful in the application because of the complex geochemical behaviors of themselves, and the complex influence factors on them.

关 键 词：Mg/Ca和Mg/Sr比值 洞穴次生化学沉积物 环境指代意义 

分 类 号：P532[天文地球—古生物学与地层学] P594[天文地球—地质学]