Stable oxygen isotope of ostracods in recent sediments of Lake Gahai in the Qaidam Basin, northwest China: The implications for paleoclimatic reconstruction
Stable oxygen isotope of ostracods in recent sediments of Lake Gahai in the Qaidam Basin, northwest China: The implications for paleoclimatic reconstruction
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中国西北柴达木盆地尕海湖沉积物中介形类稳定氧同位素：对古气候重建的意义
DOI：
10.1016/j.gloplacha.2012.06.005
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发表时间：
2012-08-01
影响因子：
3.9
通讯作者：
Xu, Liming
中科院分区：
文献类型：
--
作者：
Li, Xiangzhong;Liu, Weiguo;Xu, Liming
湖泊介形类贝壳的氧同位素组成在古湖相研究中是一个有用的指示器，并为认识湖泊体系提供了一些重要的贡献。通常，湖泊沉积物中介形类的氧同位素组成被解释为半干旱或干旱地区有效降水量、温度和蒸发/输入水比的变化。在这里，我们将柴达木盆地嘎海沉积物介形虫碳酸盐长达150年的氧同位素记录与气象数据(降水)和降水变化的树木年轮证据进行了比较。结果表明，介形类贝壳的氧同位素组成与近150年来的降水有关。总体而言，在过去的150年里，降水的增加伴随着湖水和介形虫贝壳中不太正的增量O-18值的转变，而在过去的150年里，加海的降水量减少与之相反。因此，介形类贝壳的氧同位素组成可以用来反映嘎海短时间尺度内降水的变化。(C)2012爱思唯尔B.V.保留所有权利。
The oxygen isotopic composition of ostracod shells in lakes has been used as a useful indicator in palaeolimnological research and has provided some important contributions to the understanding of lacustrine systems. Usually, the oxygen isotopic compositions of ostracods from the lake sediments are interpreted as changes in effective precipitation, temperature and evaporation/input water ratio in a sub-arid or arid area. Here, we compare a 150-year-long oxygen-isotope record that was derived from ostracod carbonate from the sediments of Lake Gahai in the Qaidam Basin with meteorological data (precipitation) and tree-ring evidence for changing precipitation. Our results show that the oxygen isotopic compositions of ostracod shells are related to precipitation over the past 150 years. In general, increased precipitation accompanied a shift to less positive delta O-18 values in the lake water, and thus in the ostracod shells, whereas decreased precipitation coincided with the opposite in Lake Gahai over the past 150 yr. Therefore, we conclude that the oxygen isotopic compositions of ostracod shells can be used to indicate changes in precipitation over a short time scale in lake Gahai. (c) 2012 Elsevier B.V. All rights reserved.