青藏高原中部错鄂湖晚新生代以来的沉积环境演变及其构造隆升意义  

Variations of Sedimentary Environments during Late Cenozoic of Co Ngoin, Central Tibetan Plateau and Its Tectonic Uplift Implications

作　　者：陈诗越[1,2] 王苏民 沈吉[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所 [2]中国科学院研究生院北京100039

出　　处：《湖泊科学》2003年第1期21-27,共7页Journal of Lake Sciences

基　　金：国家重点基础研究发展规划G 1998040810资助项目.

摘　　要：错鄂湖200m深井岩芯古地磁测年表明错鄂湖形成于约2.8Ma年前. 沉积岩性组合粒度特征和磁化率变化揭示了约3次大的沉积环境变化过程反映了至少2次剧烈的青藏高原隆升过程同时孢粉组合也揭示了构造隆升导致的植被组合的变化. 初步研究认为大的湖泊沉积环境变化主要是在青藏高原不断隆升的背景上进行的. 2.8-2.5Ma和0.8Ma以来的沉积环境演化主要受构造运动的控制而2.5-0.8Ma环境演化过程更多的受到冰期-间冰期旋回气候变化的影响.The paleomagnitism dating of the core Co Ngoin,Qinghai-Tibetan Plateau, a 200-m-depth core taken from Co Ngoin, indicates that the lake emerges at 2.8Ma BP. Lithological property, grain size and magnetic susceptibility (sus) reveal three major significant environmental variations and at least two tectonic uplifts during the last 2.8Ma. Accordingly, pollen associations open out the vegetation changes controlled by the tectonic uplift. Studies show that the major environmental changes were largely controlled by stepwise uplift of the Qinghai-Tibetan Plateau, and those numerous small changes overlapped on the large tectonic background are mainly controlled by the global climatic changes of glacial and interglacial cycles in Quaternary. The thickness of the strata above the B/M boundary is thinner, which might be resulted from the glacial cover to lead the shortage in stratigraphic thickness.

关 键 词：构造隆升 沉积环境 错鄂湖 晚新生代 古地磁 青藏高原隆升 青藏高原中部 孢粉组合 演化 间冰期 

分 类 号：P531[天文地球—古生物学与地层学]