作　　者： ; ; ; ; ; ; ; ; ;

机构地区： 华南师范大学地理科学学院

出　　处： 《中国沙漠》 2012年第4期938-946,共9页

摘　　要： 萨拉乌苏河流域米浪沟湾末次冰期早冰阶时期记录了5.5个由古沙丘砂与河流相、湖沼相构成的沉积旋回。对各沉积旋回的粒度及微量元素分析表明,河流相和湖沼相的平均粒径Mz、分选系数σ和SC/D的值明显高于古沙丘砂,河湖相中的微量元素Mn、P、Rb、Zr、V、Ni含量普遍较古沙丘砂含量高,而Ba、Co等则呈现相反的变化;这些气候代用指标的波动构成了与沉积旋回相对应的5.5个粒度及微量元素变化旋回,指示了该地末次冰期早冰阶至少经历了6次冷干和5次暖湿的气候波动,其中若干次气候回暖事件和冷干事件可与格陵兰冰芯和葫芦洞石笋等记录的D/O事件和Heinrich事件相对应。米浪沟湾剖面地层记录的千年尺度气候波动既是对东亚季风环流演变历史的体现,同时也是对全球气候变化的响应。 There are 5.5 sedimentary cycles made of aeolian facies,fluvial facie and lacustrine-swamp facies in the MGS4 segment in Salawusu River valley of China during the earlier Last Glacial.Analysis of grain size composition and trace elements contents in these sedimentary cycles shows that mean values（Mz） and standard deviation（σ） of particles size,and particle content ratio of silt＋clay and sand（SC/D） in the fluvial facie and lacustrine-swamp facies are higher than those in the aeolian facies,and the contents of Mn,P,Rb,Zr,V,and Ni in the fluvial facie and lacustrine-swamp facies are higher than those in the aeolian facies,while the contents of Ba and Co show the opposite results.The fluctuation of these proxies constitutes the 5.5 change cycles of grain size and trace elements corresponding with the above-mentioned sedimentary cycles.It indicates that at least six cold-dry events and five wet-warm events happened during the earlier stage of the Last Glacial in this region.The records of millennial scale climate fluctuations in Milanggouwan section reflect not only the evolution of the East Asian monsoon circulation,but also the global climate changes.

关 键 词： 萨拉乌苏河流域 米浪沟湾剖面 末次冰期早冰阶 粒度 微量元素 古气候

领　　域： [天文地球] [天文地球]