Factors controlling the oxygen isotopic composition of lacustrine authigenic carbonates in Western China: implications for paleoclimate reconstructions
|Author(s)||Li Huashu1, Liu Xingqi1, Tripati Aradhna2, 3, 4, Feng Shengnan1, Elliott Ben2, Whicker Chloe2, Arnold Alexandrea2, Kelley Anne Marie2|
|Affiliation(s)||1 : College of Resource Environment and Tourism, Capital Normal University, 105 West-Third-Ring North Road, Haidian District, Beijing, 100048, People’s Republic of China
2 : Department of Earth, Planetary, and Space Sciences, Department of Atmospheric and Oceanic Sciences, Institute of the Environment and Sustainability, Center for Diverse Leadership in Science, University of California, Los Angeles, CA, 90095, USA
3 : European Institute of Marine Sciences (IUEM), IFREMER, Laboratoire Géophysique et enregistrement Sédimentaire, Université de Brest, UMR 6538, Domaines Océaniques, Rue Dumont D’Urville, 29280, Plouzané, France
4 : European Institute of Marine Sciences (IUEM), IFREMER, Laboratoire Géophysique et enregistrement Sédimentaire, Université de Brest, UMR 6538, Domaines Océaniques, Rue Dumont D’Urville, 29280, Plouzané, France
|Source||Scientific Reports (2045-2322) (Springer Science and Business Media LLC), 2020-10 , Vol. 10 , N. 1 , P. 16370 (17p.)|
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 (ä18Ocarb) and its spatial distribution. Our results show that water oxygen isotopic composition (ä18Owater) rather than lake summer water temperature ( Twater), is the main determinant of ä18Ocarb, irrespective of whether oxygen isotope equilibrium is achieved. There are significant linear correlations between ä18Ocarb and elevation, as well as that between ä18Ocarb and latitude for lakes located on the Tibetan Plateau. In Western China, the spatial distribution of ä18Ocarb is consistent with that of ä18Owater, and is ultimately controlled by the isotopic composition of local precipitation (ä18Oprecipitation) that depends on the source of water vapor. Therefore, changes in ä18Ocarb can be predominantly interpreted as variations of ä18Owater, which in turn represent changes in ä18Oprecipitation for paleoclimate reconstructions in this region, and may be relevant to studies of other areas.