Increased winter-spring precipitation from the last glaciation to the Holocene inferred from a δ^(13)C_(org) record from Yili Basin(Xinjiang, NW China)  

作　　者：Keliang ZHAO Xiaoqiang LI Hai XU Xingying ZHOU John DODSON Junchi LIU 

机构地区：[1]Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences [2]CAS Center for Excellence in Life and Paleoenvironment [3]Institute of Surface-Earth System Science, Tianjin University [4]School of Earth, Atmospheric and Life Sciences, University of Wollongong [5]Institute of Earth Environment, Chinese Academy of Sciences

出　　处：《Science China Earth Sciences》2019年第7期1125-1137,共13页中国科学（地球科学英文版）

基　　金：supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB26000000);the National Natural Science Foundation of China (Grant Nos. 41772371, 41572161 & 41730319);the National Basic Research Program of China (Grant No. 2015CB953803);the Youth Innovation Promotion Association CAS;the Australian Nuclear Science and Technology Organization

摘　　要：The nature and dynamics of climate change in central Asia since the late Pleistocene are controversial. Moreover,most of the published studies focus mainly on the evolution of moisture conditions, and there have been few attempts to address changes in seasonality. In this study, records of δ^(13)C_(org), TOC, TN, C/N and grain size were obtained from lacustrine sediments at Yili Basin, Xinjiang, NW China. Our aim was to reconstruct the trend in seasonality of precipitation from the last glaciation to the Holocene. The organic matter content of the sediments is derived predominantly from terrestrial plants. The δ^(13)C_(org)values vary from-19.4‰ to-24.8‰, indicating that the vegetation was dominated by C_3 plants. Winter-spring precipitation is identified as the factor determining the relative proportions of C_3 and C_4 plants in the region. A negative trend in δ^(13)C_(org)corresponding to an increase in the relative abundance of C_3 plants indicate a trend of increasing winter-spring precipitation from the last glaciation to the Holocene. The increased incidence of wintertime storms in the interior of Asia is suggested to result in the increase of winterspring precipitation in the Holocene.The nature and dynamics of climate change in central Asia since the late Pleistocene are controversial. Moreover,most of the published studies focus mainly on the evolution of moisture conditions, and there have been few attempts to address changes in seasonality. In this study, records of δ^(13)C_(org), TOC, TN, C/N and grain size were obtained from lacustrine sediments at Yili Basin, Xinjiang, NW China. Our aim was to reconstruct the trend in seasonality of precipitation from the last glaciation to the Holocene. The organic matter content of the sediments is derived predominantly from terrestrial plants. The δ^(13)C_(org)values vary from-19.4‰ to-24.8‰, indicating that the vegetation was dominated by C_3 plants. Winter-spring precipitation is identified as the factor determining the relative proportions of C_3 and C_4 plants in the region. A negative trend in δ^(13)C_(org)corresponding to an increase in the relative abundance of C_3 plants indicate a trend of increasing winter-spring precipitation from the last glaciation to the Holocene. The increased incidence of wintertime storms in the interior of Asia is suggested to result in the increase of winterspring precipitation in the Holocene.

关 键 词：Organic matter Central Asia C3 and C4 plants SEASONALITY changes Winter-spring precipitation 

分 类 号：P532[天文地球—古生物学与地层学]