Types and Composition of Carbonate Microfacies and Analysis on Sedimentary Facies of Middle Cambrian Zhangxia Formation in Changqing,Shandong Province

This paper conducts a carbonate microfacies analysis on the Zhangxia Formation from the Zhangxia-Gushan area,Changqing County,Shandong Province.Six types of microfacies are recognized: allochthonous bioclastic packstone,epiphyton boundstones,packstone/wackestone with reworked ooids,packstone/wackestone with shell and benthic organism,ooid grainstone with radial ooids and ooid grainstone with concentric ooid.The stack pattern of these microfacies indicates five kinds of sedimentary facie: in ascending order,oolitic beach facies of restricted carbonate platform,open carbonate platform,oolitic beach facies at carbonate platform margin,algal reefs facies at carbonate platform margin and slope facies before the oolitic beach.This implies that the Zhangxia Formation in the study area should be mainly deposited in a rimmed carbonate platform.