【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34~8.5 Ma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(foreland uplift provenance)。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12 Ma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12 Ma大红沟剖面北部的柴北缘褶皱逆冲带的构造复活有关。更多还原

【Abstract】 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.更多还原