浮游有孔虫壳体Mg/Ca值——SST的替代性指标  

Mg/Ca Ratio in Planktonic Foraminifera Shells: A Proxy for the SST

作　　者：陈萍[1] 方念乔[2] 胡超涌[2] 丁旋[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研究中心,北京100083

出　　处：《地球科学（中国地质大学学报）》2004年第6期697-702,共6页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金项目"西太平洋 -北印度洋热传输与云贵地区降雨的耦合史研究"(No .40 2 72 0 74) ;安徽省教育厅自然科学基金项目 ;安徽理工大学博士基金项目"海洋生物沉积物化学指标的古环境意义研究" .

摘　　要：通过对东北印度洋区MD77181和MD81349两支岩心中Globigerinoidessacculifer壳体极为精细的清洗和溶样后 ,由ICP -MS测试获得了近 2 6 0ka以来Mg/Ca值 .结果表明Mg/Ca值与δ18O值变化趋势较为吻合 ,随温度的增加而升高 ,浮游有孔虫G .sacculifer壳体Mg/Ca值是海洋表层水温 (SST)良好的替代性指标 .运用函数式Mg/Ca =0 .4 717exp(0 .0 82 5 SST)计算表明 ,包括印度洋在内的中、低纬地区 ,LGM时期的SST与全新世的温差大于最初CLIMAP推测的2℃ ,很可能达到 4℃ .A series of Mg/Ca ratios of planktonic foraminifera shell Globigerinoides sacculifer in two cores in the NE Indian Ocean were measured by ICP-MS after careful cleaning and dissolving. The results show Mg/Ca ratio and δ18 O change accordingly. The Mg/Ca ratio increases with the rise of temperature. This study demonstrates Mg/Ca ratio of planktonic foraminifera shell may serve as a proxy for the past sea surface temperatures (SST). The formula Mg/Ca = 0.4717 exp (0.0825 * SST) was applied to calculating and the result shows that in low and middle latitudes, including the NE Indian Ocean, the difference of SST between LGM and the Holocene is about 4°C which is higher than the 2°C estimated by CLIMAP.

关 键 词：浮游有孔虫壳 Mg/Ca值 海洋表层水温(SST) 

分 类 号：P53[天文地球—古生物学与地层学]