贵州宗地上石炭统达拉阶—下二叠统隆林阶的沉积微相组合及其沉积环境

The Assemblages of Microfacies and the Sedimentary Environment of the Upper Carboniferous Dalaian to the Lower Permian Longlinian in the Zongdi Section, Guizhou Province

根据镜下薄片统计结果,参照野外观察,采用R型和Q型聚类分析方法对贵州省紫云县宗地乡上石炭统达拉阶—下二叠统隆林阶的沉积环境进行了研究。分析结果表明,贵州宗地达拉阶—隆林阶存在11种微相类型,分别为深水局限泻湖、浅水局限泻湖、深水藻丘、接近浅滩的洼地、台地边缘浅滩、深水泻湖、浅水藻丘、浅水泻湖或潮坪、潮汐砂坝、局限浅滩或泻湖和深水斜坡等环境的沉积。不同的微相类型在剖面纵向上构成了6个微相组合,代表了沉积环境依时间变化的6个基本过程浅滩或潮坪—开阔台地—藻丘—局限台地—深水斜坡—局限藻丘。

The cluster analysis method has been applied in a comprehensive study to investigate the sedimentary environment of the Upper Carboniferous Dalaian to the Lower Permian Longlinian of the Zongdi section, Guizhou Province, Southwest China, based on the statistic materials by microscope and referring to the observation in the field. Results of analyses show that there are 11 microfacies in the Zongdi section, namely, deep restricted lagoon, shallow restricted lagoon, deep alga mound, depression near shallow beach, shallow beach of platform margin, deep lagoon, shallow alga mound, shallow lagoon or tidal flat, tidal bar, restricted shallow beach or lagoon and deep slope. The assemblages and distribution patterns of the microfacies in the section demonstrate that the sedimentary environments during the Upper Carboniferous Dalaian to the lower Permian Longlinian experienced 6 basic processes, namely, shallow beach, open platform, alga mound, restricted platform, deep slope and restricted mound.