Long-chain alkenones in sulfate lakes and its paleoclimatic implications

作     者：SUNQing CHUGuoqiang LIShengqiang LUCaifen ZHENGMianping 

作者机构：NationalResearchCenterofGeoanalysisBeijing100037China InstituteofGeologyandGeophysicsChineseAcademyofSciencesBeijing100029China CenterforAnalysisandPredictionCSBBeijing100036China InstituteofMineralResourcesandOpenLaboratoryofSalineLakeResourcesandEnvironmentChineseAcademyofGeologicalSciencesBeijing100037China 

出 版 物：《Chinese Science Bulletin》 (中国科学通报)

年 卷 期：2004年第49卷第19期

页      面：2082-2086页

核心收录：

学科分类：07[理学] 08[工学] 081501[工学-水文学及水资源] 0705[理学-地理学] 0815[工学-水利工程] 070501[理学-自然地理学] 

基　　金：National Natural Science Foundation of China, NSFC, (40102016, 49833010) National Natural Science Foundation of China, NSFC 

主　　题：U37^K 古温 温度测定 古气候 长链烯酮 硫酸盐湖 

摘      要：The proxy of U37 index is widely applied to K ’ 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 —10 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 uni- versal in the sulfate lakes. In most of the surface samples, the sequence of the abundance of the long-chain alkenones is C37C38C39C40. And C37︰4 methyl ketone is a predominant compound in the C37 alkenone homologue. Based on regres- sion analysis of U37 -ratios and the average annual, seasonal K ’ (spring, summer, autumn, winter) temperatures, the linear K ’ relativity of U37 -ratios and mean annual temperatures is superior to the others, and the correlation coefficient is 0.88 (r2 = 0.88). The linear relationship of U37 and the average K ’ annual temperature in different water chemistry environ- K ’ ments suggests that the mechanisms controlling U37 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 envi- ronment.