中中新世南祁连山的构造抬升——来自柴达木盆地大红沟剖面的沉积证据  

The Mid-Miocene tectonic uplift of southern Qilianshan:Sedimentary evidence from Dahonggou section in Qaidam Basin

作　　者：卢海建[1] 王二七[2] 孟恺[2] 

机构地区：[1]中国地质科学院地质研究所大陆构造与动力学国家重点实验室,北京100037 [2]中国科学院地质与地球物理研究所特提斯研究中心,北京100029

出　　处：《地质科学》2014年第1期95-103,共9页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国科学院战略性先导科技专项(B类)"高原边界扩展过程与机制"(编号:XDB030105);国家"973"项目"青藏高原南部大陆聚合与成矿作用"(编号:2011CB403106);国家自然科学基金项目(编号:41002053)资助

摘　　要：山间盆地中的碎屑沉积是周围山脉隆升信息的记录载体。本文对柴达木盆地中北部大红沟剖面砂岩中的碎屑含量进行了详细的分析。结果显示在34～8．5Ma大红沟剖面的物源区性质没有发生改变，均为前陆隆升物源（forelandupliftprovenance）。但是，砂岩中的石英、长石、岩屑含量均呈现了两阶段的演化特征，在12Ma发生了快速的大幅变化。这些现象与以前通过沉积学、沉积速率、磁化率等分析获得的结果是一致的。成因上，这可能与12Ma大红沟剖面北部的柴北缘褶皱逆冲带的构造复活有关。The clastic sediments in intermontane basins record typically a wealth of information on uplift of adjacent mountains. This study conducted detailed analyses of detrital content of sandstones for the Dahonggou section in north-central Qaidam Basin. The results indicate that the provenance area of the Dahonggou section did not change in nature from 34 Ma to 8.5 Ma and was foreland uplift provenance. However,the values of quarts,feldspar and lithic fragments in sandstones collectively displayed two-stage evolution characteristics and varied significantly at 12 Ma. Those observations are consistent with that obtained by sedimentology,sedimentation rate, and magnetic susceptibility analyses. Presumably, it was very likely associated with the tectonic reactivation of northern Qaidam thrust belts north of Dahonggou section at 12 Ma.

关 键 词：沉积物 物源分析 构造抬升 大红沟剖面 柴达木盆地 

分 类 号：P542[天文地球—构造地质学]