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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。
Detrital sediments in the mountain basin are the record carriers for the upwelling of the surrounding mountains. In this paper, the detritus content of sandstone in Dahonggou section in central-northern Qaidam Basin is analyzed in detail. The results show that there is no change in the nature of the source region in the Dahonggou section from 34 to 8.5 Ma, and both are foreland uplift provenance. However, the contents of quartz, feldspar and lithic fragments in sandstone show a two-stage evolution, with rapid and sharp changes occurring at 12 Ma. These phenomena are consistent with the results previously obtained from sedimentology, sedimentation rates, magnetic susceptibility and other analyzes. This may be related to the tectonic revival of the fold-thrust belt in the northern Qaidam basin of the 12 Ma Dahonggou profile.