中文摘要：

通过对峡东地区下寒武统天河板组底部鲕粒灰岩进行微相分析,划分出放射鲕型鲕粒灰岩（SMF15-R）、同心鲕型鲕粒灰岩（SMF15-C）以及微晶鲕型鲕粒灰岩（SMF15-M）三种不同类型的鲕粒灰岩亚相。通过与标准微相类型中镶边碳酸盐岩台地模式和缓坡模式相带对比,认为研究区鲕粒形成于镶边碳酸盐岩台地内部局限环境至台地边缘鲕滩相的沉积环境。对鲕粒粒径大小和类型的分析,支持后期海侵事件的存在。

英文摘要：

Based on the study of the oolitic limestone of Tianheban Formation,Lower Cambrian in the east part of the Three Gorges area,it can be divided into three different types of sub-microfacies： ooidal grainstone with radial ooids（SMF15-R）,ooid grainstone with concentric ooids（SMF15-C）and Quartz-bearing ooidal wackestone with micritic ooids（SMF15-M）.Compared with the standard microfacies models of the carbonate ramp（not platform？）model,the ooids formed in the rimmed carbonate platform model,from restricted-marine platform to platform-edge.The analysis of the grain-size and types supports the transgressive event.