西昆仑甜水海-麻扎地块上石炭统恰提尔群B组沉积环境分析

Sedimentary environments of the B Formation of the Upper Carboniferous Qiati' er Group in the Tianshuihai-Mazar block,western Kunlun Mountains

本文在详细描述甜水海-麻扎地块上石炭统恰提尔群B组地层剖面基础上,结合野外沉积构造、室内薄片鉴定、粒度分析成果,讨论了该组的岩石组合特征和沉积环境。其岩性组合为细砂岩、粉砂岩、泥岩、页岩等碎屑岩类,为一套湖陆过渡的三角洲沉积,可进一步划分为三角洲平原、三角洲前缘与前三角洲3个沉积亚相,其物源区为再循环造山带、混合物源区。

The petrographic associations and sedimentary environments are treated for the B Formation of the Upper Carboniferous Qiati ＇er Group in the Tianshuihai-Mazar block, western Kunlun Mountains in terms of sedimentary structures, thin section and grain-size analysis. The lithology in the Formation consists of fine-grained sandstone, siltstone, mudstone and shale, which are involved into a succession of lacustrine-continental delta deposits. The delta facies may be subdivided into the delta plain, delta front and prodelta subfacies. The detritus come from the recycled orogen and mixed source areas. The results of research in this study will provide important information for better understanding of the tectonic evolution of western Qinghai-Xizang Plateau.