贵阳花溪地区下三叠统大冶组沉积微相分析

Sedimentary Microfacies of the Lower Triassic Daye Formation in Huaxi,Guiyang

二叠纪-三叠纪之交贵阳花溪地区处于碳酸盐岩台地环境。二叠纪末的全球事件在该区改毛剖面的沉积微相和生物演化上均留下了较为清楚的记录。通过测制改毛剖面,野外考查沉积构造、岩性特征及采集化石标本,结合镜下显微观察,对大冶组各层进行微相分析,初步划分为4种沉积相、6种微相,反映该地区大冶组底部海侵期为浅海台地边缘环境,发展至大冶组中部为海平面相对上升的台缘下斜坡半浅海环境,之后又恢复至大冶组顶部台地前缘斜坡浅海环境。

Huaxi,Guiyang during Permian-Triassic Period lay in a carbonate platform environment.The global events of biotic crisis at the end of the Permian was highly marked both on fossil record and sedimentary microfacies in the Gaimao Section.This paper deals with sedimentary facies of the Daye formation in the Gaimao section,Huaxi,Guiyang which may be divided into4facies and6microfacies.These indicate that change of sedimentary environment of the Daye Formation from shallow marine platform-margin environment through platform-margin slope under half a shallow marine environment to the platform foreslope neritic environment.