柴达木盆地SG-1孔1．0Ma以来碳酸盐同位素记录的亚洲内陆干旱化及成因  

ARIDIFICATION OF THE ASIAN INLAND SINCE 1.OMa:EVIDENCES FROM CARBONATE ISOTOPE RECORDS OF DEEP CORE FROM THE QAIDAM BASIN

作　　者：滕晓华[1,2] 韩文霞[2] 叶程程[3] 张志高[1] 彭文彬[1] 方小敏[1,3] 

机构地区：[1]兰州大学西部环境教育部重点实验室,西部环境与气候变化研究院,兰州730000 [2]中国科学院青海盐湖研究所盐湖资源与化学重点实验室,西宁810008 [3]中国科学院青藏高原研究所大陆碰撞与高原隆升重点实验室,北京100101

出　　处：《第四纪研究》2013年第5期866-875,共10页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:40920114001和41021001);国家重点基础研究发展规划项目(973项目)(批准号:2013CB956400和2011CB403000);德国联邦教研部项目(批准号:03G0705A);中国博士后科学基金项目(批准号:2012M521823)共同资助

摘　　要：亚洲内陆干旱区是连接赤道和中高纬地区的过渡地带,也是西风气候和季风气候的相互作用区,其形成演化与青藏高原的隆起和全球变化等因素密切相关。因此,揭示其干旱化过程和趋势具有重大的理论和现实意义。文章对来自柴达木盆地察汗斯拉图干盐湖的深钻SG-1孔沉积物进行了初步的碳酸盐碳氧同位素测试与分析,结果清晰地指示了柴达木盆地自1.0Ma以来的持续干旱化及约0.6Ma以来的加速干旱化过程,我们认为1.0Ma以来的持续干旱化可能是全球气候变化和构造活动共同作用的结果,而约0.6Ma以来的加速干旱化可能是昆黄运动所导致的高原北部强烈隆升和区域环流系统变化或强化所造成的。As the largest temperate arid region,the vast Asian arid inland has attracted wide interests due to its great impacts on global climatic change.However,its evolution history and its relation with the westerlies,Tibet uplifts and global change are still unknown.Although many related studies have been carried out,most of the studies are mainly based on the eolian records from the surrounding areas,and only few records are directly from this arid region. The Qaidam basin,located in the eastern part of this vast arid region,develops continuous and well-exposed Cenozoic sediments,providing a unique opportunity to study aridity of the Asian inland.We obtained a 938.5m long lake sediment core（SG-1）（38°24＇35.3＂N,92°30＇32.6＂E;2700m a.s.l.）with an average recovery rate of 95% from the saline playa in the depocenter of the Chahansilatu sub-basin between the Eboliang anticline and the Jianshan anticline in the western Qaidam basin.A combined detailed paleomagnetic dating, OSL and U series dating of the core determined its age at about 2.77Ma to 0.10Ma. The core is mainly comprised of evaporate-bearing fine mudstone-siltstone sequence.In the lower 390.0~938.5m part of the core,the sediments consist mainly of alternation of dark-gray or bluish-gray generally laminated mudstone and siltstone and gray calcareous mudstone and marl/limestone.In the upper 0~390m part of the core,the lithology is characterized by cycles of thick gray-white salt and grayish black massive-laminated mudstone-siltstone mostly containing gypsum crystals or thin gypsum layers.This study mainly carries out a more detailed analysis of carbon and oxygen isotopes for the upper 0~350m part of the core with 0.1~1.0Ma.Samples with high carbonate contents （ 〉30wt% ） were systematically collected at an average interval of ca.3m and 135 samples were selected.We collected 12 rock samples（including limestone and marble）from exposed strata since Precambrian in the surrounding Kunlun,Qilian and Altun major river basins to determine the carbo

关 键 词：干旱化 亚洲内陆 碳酸盐碳氧 同位素柴达木盆地 西风环流 

分 类 号：P534.63[天文地球—第四纪地质学] P941.75[天文地球—古生物学与地层学]