柴达木察尔汗贝壳堤剖面Sr同位素及其环境意义

柴达木察尔汗贝壳堤剖面Sr同位素及其环境意义

牛洁1,张虎才1,2★，常凤琴1，陈玥1，樊红芳1，张文翔1，杨明生1，雷国良1

1.兰州大学资源环境学院，西部环境教育部重点实验室，兰州 730000； 2.中国科学院南京地理与湖泊研究所，南京 210008； ★ 通讯联系人：张虎才Email:zhanghc@niglas.ac.cn

收稿日期:2007-03-20 修回日期:2007-03-20 出版日期:2007-03-20 发布日期:2007-03-20

The 87Sr/86Sr ratios of shell bar section at Charhan Lake, Qaidam Basin and its paleoenvironmental significance

NIU Jie1,ZHANG Hucai2,1★,CHANG Fengqin1, CHEN Yue1,FAN Hongfang1,ZHANG Wenxiang1,YANG Mingsheng1 ,LEI Guoliang1

1. Key Laboratory of Western China’s Environments, MOE, College of Earth Sciences and Environments, Lanzhou University, Lanzhou 730000, China; 2.Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China;★Corresponding author： Zhang H.C. Email: Zhanghc@niglas.ac.cn

Received:2007-03-20 Revised:2007-03-20 Online:2007-03-20 Published:2007-03-20

摘要/Abstract

摘要： 根据对柴达木盆地察尔汗古湖贝壳堤剖面酸不溶组分和酸溶组分的提取及其87Sr/86Sr的测定，结合沉积物中Rb/Sr的变化，指出Sr同位素组成特征可有效指示源区化学风化和沉积区古环境变化；依据酸溶组分中盐度指标Sr/Ca, Sr/Ba值与Sr同位素组成曲线的对比分析，揭示酸溶组分Sr同位素可以较好的指示水体形成时的盐度。通过分析贝壳堤剖面化学风化和部分盐度变化过程，探讨了研究区晚更新世39.6~ 17.1 ka BP(未经校正的AMS 14C测年结果，全文同)湖泊高湖面的演化历史。

Abstract: The data for 87Sr/86Sr, Rb/Sr and Sr contents of the acetic acid soluble components and insoluble components of shell bar section at southeastern Charhan saline lake, Qaidam Basin were presented. According to the environmental significance of Rb/Sr ratios of lake sediments, our data showed that, 87Sr/86Sr ratios can effectively indicate the catchment chemical weathering intensity and the paleoenvironmental changes of the deposit area; Correlation of 87Sr/86Sr with Sr/Ca and Sr/Ba ratios (salinity parameters) of the carbonate fractions indicates that the variation in carbonate 87Sr/86Sr values can be used to reflect the salinity of the water under formation condition. Based on chemical weathering intensities and salinity variations along the sequence, the environmental change history was reconstructed between 39.6 ka BP and 17.1 ka BP for the studied area. The high lake level was maintained between 33.2 ka BP and 27.4 ka BP, both the temperature and precipitation amount were higher than those of the present day. Till about 18 ka BP, the lake started to shrink, probably suggesting that the climate turned from a warmhumid interstadial into a colddry glacial climate.

牛洁,张虎才,★，常凤琴，陈玥，樊红芳，张文翔，杨明生，雷国良. 柴达木察尔汗贝壳堤剖面Sr同位素及其环境意义[J]. J4.

NIU Jie1,ZHANG Hucai2,1★,CHANG Fengqin1, CHEN Yue1,FAN Hongfang1,ZHANG Wenxiang1,YANG Mingsheng1 ,LEI Guoliang1. The 87Sr/86Sr ratios of shell bar section at Charhan Lake, Qaidam Basin and its paleoenvironmental significance[J]. J4.