摘要：

鄂西宜昌地区寒武系出露齐全、连续，且岩石类型多样、化石丰富，是我国寒武系的标准剖面之一。其沉积环境以潮下高能浅滩为主，其次为间歇能量的潮间带、滨岸的中小型浅滩，少数为开阔海较深处的静水灰泥沉积。石灰岩集中分布于下寒武统天河板组和水井沱组，其次在下寒武统的石牌组、中寒武统的磕膝包组、官山瑙组有少量夹层出现。其岩石类型有颗粒灰岩（鲕粒灰岩、核形石灰岩、砾屑灰岩及砂屑灰岩）、含颗粒泥粉晶灰岩（含生屑泥粉晶灰岩、含生屑灰岩）及泥晶灰岩。白云岩是本地区数量最多的岩石类型。从下寒武统石龙洞组开始都是白云岩沉积，白云岩可据白云石化作用机理和时间的不同分为准同生白云岩和准同生后白云岩两大类。准同生白云岩广泛出现于中上寒武统，岩石呈土黄色、砖红色，具纹层、鸟眼、干裂构。准同生后白云岩根据残余颗粒的有无可分为残余颗粒白云岩和晶粒白云岩两大类。晶粒白云岩有两种成因。一为回流渗透云化；二为深埋藏云化。根据本区寒武系岩石的岩石学特征、生物组合特征和结构构造特征本文重建了各组段的沉积环境.

Abstract:

The carbonate rocks of the Cambrian in Yichang area are well developed. Limestone is mainly distributed in the Tianheban Formation and Shuijingtuo Formation of the lower Cambrian, as well as the Shipai Formation of the lower Cambrian and Keqibao Formation and Guanshannao Formation of the middle Cambrian. It can be divided into grain limestone (oolitic limestone, oncolitic limestone, calcirudite and calcarenite), grain-bearing micritic limestone (bioclast-bearing micritic limestone) and micritic limestone. Dolostone is the main rock type of this area. According to the mechanism of dolomitization, it can be divided into penecontemporaneous dolostone and post-penecontemporaneous dolostone.  Micritic dolostone distributes widely in the middle and upper Cambrian and is yellowish brown and brick-colored red, in which parallel laminae, bird’s-eyes and mud-cracks are developed. According to whether remnant grains exist, post-penecontemporaneous dolostone can be divided into remnant grain dolostone and crystalline dolostone. Crystalline dolostone is formed by seepage-reflux dolomitization and burial dolomitization.    According to petrology, biological assemblage and structural features of carbonate rocks, the auther reconstructed the sedimentary environments of formations of the carbonates in Yichang area.