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With continuous outcrops, developed shoal fades rocks, complete types of diagenesis and changeable diagenetic environments, Cambrian strata are well developed in the Xiadong area, Yichang, Hubei Province. Under the combined influence of numerous diageneses, secondary pores can be formed, which result in better reservoir properties of the rock strata.The Cambrian rocks in this area consist of mainly carbonate rocks and secondarily detrital rocks. The carbonate rocks are dominated by grainstones including wormkalk, calcirudite-calcarenite, oolitic limestone and oncolitic limestone. Graded bedding and cross bedding are well developed in the strata, which indicates that the formation environment is of a high-energy shoal facies.In this area, there has developed a sequence of stable Cambrian platform carbonate deposition. The evolution trend is as follows: open sea shelf facies→intertidal low-energy restricted sea facies→Hntertidal high-energy shoal facies→coastal shoal facies→evaporite tidal-flat facies
Under continuous combination of numerous diagenesis, secondary pores can be formed, which result in better reservoir properties of the rock strata. Cambrian rocks in this area consist of mainly carbonate rocks and secondarily detrital rocks. The carbonate rocks are dominated by grainstones including wormkalk, calcirudite-calcarenite, oolitic limestone and oncolitic limestone. well developed in the strata, which indicates that the formation environment is of a high-energy shoal facies.In this area, there has had developed a sequence of stable Cambrian platform carbonate deposition. The evolution trend is as follows: open sea shelf facies → intertidal low-energy restricted sea facies → Hntertidal high-energy shoal facies → coastal shoal facies → evapo rite tidal-flat facies