罗布泊中更新世以来盐湖碳酸盐碳氧同位素组成及其古环境意义  

Carbon and Oxygen Isotopic Compositions of the Lacustrine Carbonate in Lop Nur Since the Mid-Pleistocene and Their Paleoenvironment Significance

作　　者：吕凤琳[1,2,3] 刘成林 焦鹏程[1] 张华[1] 孙小虹[1] 张永明[3,4] Lu Fenglin;LIU Chenglin;JIAO Pengcheng;ZHANG Hua;SUN Xiaohong;ZHANG Yongming(MLR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing,100037,China;China University of Geosciences,Beijing,100083,China;Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xi~ ning,810008,China;Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province,Xi ＇ ning,810008,China)

机构地区：[1]中国地质科学院矿产资源研究所成矿作用与资源评价重点实验室,北京100037 [2]中国地质大学(北京),北京100083 [3]中国科学院青海盐湖研究所中国科学院盐湖资源综合高效利用重点实验室,西宁810008 [4]青海省盐湖资源化学重点实验室,西宁810008

出　　处：《地质学报》2018年第8期1589-1604,共16页Acta Geologica Sinica

基　　金：国家自然科学基金重点项目(编号40830420)资助的成果

摘　　要：罗布泊是欧亚大陆腹地塔里木盆地东端的典型内陆干盐湖,中更新世以来在其北部尤其罗北凹地发育了巨厚的蒸发岩沉积是对全球变冷和青藏高原隆升的积极响应。通过对罗北凹地第一口深钻LDK01孔蒸发岩系中203个样品的自生碳酸盐含量、碳氧同位素测试与分析,讨论了罗布泊中更新世以来的古环境演化特征。研究表明:(1)δ^(18) O和δ13 C协同正向演化,但在蒸发作用强烈的干旱封闭湖泊中,流域降蒸比(P/E)的变化对湖泊水体δ^(18) O影响最为显著;(2)δ^(18) O和δ13 C周期性波动震荡特征,反映干湿交替的环境以及周缘水体对罗北凹地的补给;(3)罗布泊湖盆干旱加剧演化可能并非只受全球变化单一因素驱动,而是全球气候变化和高原隆升共同作用的结果。Lop Nur is a typical inland dry salt lake in the eastern end of the Tarim Basin within the interior of Eurasian continent. Thick evaporite was developed in the northern depression since the middle Pleistocene, and this was active response to global cooling and uplift of the Qinghai-Tibet plateau. In this study, carbonate content, carbon and oxygen isotopic compositions were analyzed for 203 samples of evaporite series from the first deep core （LDK01） in the Luobei depression to reveal evolution features of paleoenviroment in Lop Nur since the middle Pleistocene. The research indicates that： （1） 81~O and 813C values show an obvious synchronous increasing trend, and the evaporation and precipitation ratio has the most significant influence over 8TM O of water in the lakes, especially in the arid region~ （2） Periodic fluctuation of 81sO and 81aC indicates an environment of alternating wet and dry paleo-environment and the variations of the runoff into Luobei depression; （3） Rapid aridification of Lop Nur should not be driven solely by global climate change, and be the joint result of cooling of global climate and uplift of the Tibetan Plateau.

关 键 词：罗布泊 中更新世 碳氧同位素 古环境 

分 类 号：P532[天文地球—古生物学与地层学] P597[天文地球—地质学]