Long-chain alkenones in sulfate lakes and its paleoclimatic implications

• Published in: Chinese science bulletin Vol. 49; no. 19; pp. 2082 - 2086
• Main Authors: Sun, Qing, Chu, Guoqiang, Li, Shengqiang, Lü Caifen, Zheng Mianping
• Format: Journal Article
• Language: English
• Published: Beijing Springer Nature B.V 01.10.2004; National Research Center of Geoanalysis, Beijing 100037, China%Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China%Center for Analysis and Prediction, CSB, Beijing 100036, China%Institute of Mineral Resources and Open Laboratory of Saline Lake Resources and Environment, Chinese Academy of Geological Sciences, Beijing 100037, China
• Subjects: Correlation coefficient; Correlation coefficients; Ketones; Lakes; Marine environment; Regression analysis; Relativity; Saline environments; Salt lakes; Sediments; Sulfates; U37^K; Water chemistry; 古气候; 温度测定; 硫酸盐湖; 长链烯酮; China, People's Rep., Qinghai Prov; China, People's Rep., Inner Mongolia; Spain, Andalucia, Almeria, Salines L; China, People's Rep., Xinjiang; temperature; long-chain alkenone; UK'37; sulfate lake
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1360/03wd0298

The proxy of U37^K index is widely applied to reconstructing paleotemperature in the marine environment. However, the long-chain alkenones (LCAs) research is rarely reported in the liminic system. In this paper, we studied LCAs in the surface sediments (0---I0 cm) of nine sulfate lakes in the Inner Mongolia Autonomous Region, Xinjiang Uygur Autonomous Region and Qinghai Province, China. LCAs are detected in eight of the nine lakes, except a dry salt lake-Lake Lop. The result shows that LCAs might be universal in the sulfate lakes. In most of the surface samples, the sequence of the abundance of the long-chain alkenones is C37>C38>C39>C40. And C37:4 methyl ketone is a predominant compound in the C37 alkenone homologue. Based on regression analysis of U37^K-ratios and the average annual, seasonal(spring, summer, autumn, winter) temperatures, the linearrelativity of U37^K-ratios and mean annual temperatures is superior to the others, and the correlation coefficient is 0.88(r^2=0.88). The linear relationship of U37^K and the average annual temperature in different water chemistry environments suggests that the mechanisms controlling U37^K index in the saline lakes might be the same as those in the ocean environment. The alkenone unsaturation could become an important paleotemperature proxy in the lacustrine environment.