青海沱沱河地区晚三叠世苟鲁山克措组沉积相及物源分析

Sedimentary Facies and Provenance Analysis of Upper Triassic Goulushankecuo Formation in Tuotuohe Area of Qinghai Province

通过野外实测地层剖面、沉积相标志识别、薄片鉴定和粒度分析等手段,研究了沱沱河地区三叠纪苟鲁山克措组的沉积相类型和沉积特征。结果表明苟鲁山克措组为一套三角洲浅海陆棚体系。物源分析采用碎屑岩类法,研究表明工作区三叠纪砂岩多为长石岩屑砂岩和岩屑石英砂岩,结构成熟度和成分成熟度均较低,显示了沉积物快速堆积,近物源的特征。通过对碎屑矿物的成分分析,揭示其物源源于再旋回造山带。

Through field profile measuring, sedimentary facies signs identification, thin section authentification and grading analysis, we studied the categories and features of sedimentary facies of Upper Triassic Goulushankecuo Formation. The results show that the Goulushankecuo Formation is a Delta-Neritic shelf facies system. Based on clasolite petrographic study, the statistics from provenance analysis show that the sedarenite of Triassic Goulushankecuo Formation in workspace are mainly feldspathic litharenite and lithic quartz sandstone. Lower textural and com- positional maturity indicates a rapid accumulation of sediments, which is a characteristic of nearby provenance. By detrital composition analysis, it is revealed that the provenance of Upper Triassic Goulushankecuo Formation came from recycled orogen.