有孔虫壳体δ^(44)Ca的古海洋学意义  

Glacial-Interglacial Variations of δ^(44)Ca Recorded by Planktonic Foraminifera

作　　者：陈萍[1] 方念乔[2] 胡超涌[2] 

机构地区：[1]安徽理工大学资源与环境工程系,安徽淮南232001 [2]中国地质大学海洋地学中心,北京100083

出　　处：《安徽理工大学学报（自然科学版）》2006年第4期11-16,共6页Journal of Anhui University of Science and Technology:Natural Science

基　　金：国家自然科学基金资助项目(40272074)

摘　　要：钙同位素是近些年被人们注意的海洋中阳离子同位素,为研究古海洋中钙同位素与海洋环境的变化状况,以东北印度洋MD 81349岩芯为研究对象,由多接受杯电感耦合等离子体质谱仪(ISOPROBE)获得了浮游有孔虫G lobigerinoid es saccu lif er壳体92个样品的钙同位素组成4δ4Ca值。研究表明:海水中4δ4Ca变化记录在有孔虫的钙质壳体中,海洋生物的发育状况,冰期的高生产力和间冰期的低生产力极有可能是控制海水及有孔虫壳体4δ4Ca值波动的主要原因。高生产力阶段Ca同位素分馏作用强,较多的轻质40Ca优先进入生物体内而使海水中44Ca升高,记录在有孔虫壳体中的4δ4Ca值呈高值;相反,低生产力阶段Ca同位素分馏作用弱,海水中44Ca相对降低,记录在有孔虫壳体中的4δ4Ca值呈低值。Calcium isotope, a positive ion in ocean, has been studied in recent years . A series of δ^44Ca data of planktonic foraminifera shell Globigerinoides sacculifer in the core MD81349 from the NE Indian Ocean were measured by ISOPROBE. The variations of δ^44Ca in sea water were recorded in the planktonic foraminifera shell and the fluctuation in glacial and interglacial are caused by the quantity of oceanic creatures. During the high productivity, calcium isotope plays a crucial role in isotopic distillation. The ^40Ca, more light isotope, enters creatural shell first, resulting in an increase of ^44Ca in sea water and a high value of ^44Ca in creatural shell. Contrarily, during the low productivity, calcium isotope plays a weak role in isotopic distillation, resulting in a decrease of ^44Ca in sea water and a low value of δ^44Ca in creatural shell.

关 键 词：有孔虫壳体 δ^44Ca冰期 生物生产力 

分 类 号：P736.43[天文地球—海洋地质]