Oxygen isotopic composition of lacustrine carbonates since 130 ka  from a Tianshuihai Lake core, Tibet: an overall increasing δ¹⁸O trend and its implications

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• 作者：Houyun ; Zhou ; Zhaoyu ; Zhu
• 关键词：Precipitation ; Marine moisture sources ; Continental moisture sources ; Late Quaternary ; Tibetan uplift
• 刊名：Journal of Asian Earth Sciences
• 出版年：2002
• 出版时间：February, 2002
• 年：2002
• 卷：20
• 期：3
• 页码：225-229
• 全文大小：104 K

文摘

The oxygen-isotopic composition of lacustrine authigenic carbonates from a core taken from Lake Tianshuihai in western Qinghai-Tibet Plateau shows an overall increasing δ¹⁸O trend (OIT) from about 130 to 15kabp. Based on the argument by that the δ¹⁸O of lacustrine carbonates from lakes in west China is controlled mainly by the δ¹⁸O of the local precipitation, we propose that this OIT may have resulted from a similar OIT of δ¹⁸O of precipitation over the drainage area of the Tianshuihai Lake. This OIT suggests that from about 130 to 15kabp, variations of δ¹⁸O of precipitation on the Qinghai-Tibet Plateau were controlled mainly by changes, not in temperature, but in moisture sources, especially in the ratio of precipitation of moisture from marine sources (MMS) to that from continental evaporation (MCE). The changes in the sources of the moisture and in the MMS/MCE ratio may be mainly a function of the uplift of the Qinghai-Tibet Plateau.