文章基本信息

标题：Factors controlling the oxygen isotopic composition of lacustrine authigenic carbonates in Western China: implications for paleoclimate reconstructions
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作者：Huashu Li ; Xingqi Liu ; Aradhna Tripati 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2020
卷号：10
期号：1
页码：1-17
DOI：10.1038/s41598-020-73422-4
出版社：Springer Nature
摘要：In the carbonate-water system, at equilibrium, the oxygen isotopic composition of carbonate is dependent not only on the temperature but also on the isotopic composition of host water in which the carbonate is formed. In this study, lake surface sediment and water samples were collected from 33 terminal lakes in Western China to evaluate controls on the oxygen isotopic composition of lacustrine authigenic carbonates (δ18Ocarb) and its spatial distribution. Our results show that water oxygen isotopic composition (δ18Owater) rather than lake summer water temperature (Twater), is the main determinant of δ18Ocarb, irrespective of whether oxygen isotope equilibrium is achieved. There are significant linear correlations between δ18Ocarb and elevation, as well as that between δ18Ocarb and latitude for lakes located on the Tibetan Plateau. In Western China, the spatial distribution of δ18Ocarb is consistent with that of δ18Owater, and is ultimately controlled by the isotopic composition of local precipitation (δ18Oprecipitation) that depends on the source of water vapor. Therefore, changes in δ18Ocarb can be predominantly interpreted as variations of δ18Owater, which in turn represent changes in δ18Oprecipitation for paleoclimate reconstructions in this region, and may be relevant to studies of other areas.
其他摘要：Abstract In the carbonate-water system, at equilibrium, the oxygen isotopic composition of carbonate is dependent not only on the temperature but also on the isotopic composition of host water in which the carbonate is formed. In this study, lake surface sediment and water samples were collected from 33 terminal lakes in Western China to evaluate controls on the oxygen isotopic composition of lacustrine authigenic carbonates (δ 18 O carb ) and its spatial distribution. Our results show that water oxygen isotopic composition (δ 18 O water ) rather than lake summer water temperature (T water ), is the main determinant of δ 18 O carb , irrespective of whether oxygen isotope equilibrium is achieved. There are significant linear correlations between δ 18 O carb and elevation, as well as that between δ 18 O carb and latitude for lakes located on the Tibetan Plateau. In Western China, the spatial distribution of δ 18 O carb is consistent with that of δ 18 O water , and is ultimately controlled by the isotopic composition of local precipitation (δ 18 O precipitation ) that depends on the source of water vapor. Therefore, changes in δ 18 O carb can be predominantly interpreted as variations of δ 18 O water , which in turn represent changes in δ 18 O precipitation for paleoclimate reconstructions in this region, and may be relevant to studies of other areas.