青海巴颜喀拉山三叠系复理石沉积粒度 概率累积曲线的特征

巴颜喀拉山群为碎屑岩复理石沉积。粒度概率累积曲线分析结果表明，完全为悬浮总体的浊积型曲线很少．曲线主要由牵引和悬浮总体组成。碎屑流是巴颜喀拉山群砂岩主要的成因类型。粒度参数特征表明，巴颜喀拉山盆地由早到晚平均粒径变粗、分选变好。风暴岩序列不同阶段粒度概率累积曲线形态不同，粒度曲线特征与被改造砂体的组成有关。

Probability cumulative grain-size curves of Triassic flysch deposits in the Bayan Har Mountains area, Qinghai, China

The Bayan Har Group consists of flysch deposits. The probability cumulative grain-size curves reveal that: there appear few turbidite-type curves represented completely by the suspension population and the curves are composed principally of the traction and suspension populations. Debris flows are the dominant genetic type of sandstone of the Bayan Har Group. Granulometric parameters show that: the average grain size in the Bayan Har basin becomes coarser with time and the sorting becomes better. The features of probability cumulative grain-size curves in different stages of the tempestite sequence are related to the composition of modified sandstone bodies.