Abstract:

There are five types of organic reefs of Changxing stage in East Sichuan:patch reefs on carbonate platform rises and flat,shelf margin reefs and patch reefs in back reef la-goons,and patch reefs near restricted sea.The formation of typical patch reefs was related to the fluctuation of earth crust at the end of the Permian,forming reef core facies,constructed by saccoliths of bound-stones,interchangeably with intermittent shoal facies.Facies-selective dolomitization and dissolution in different stages resulted in the reservoirs of intermittent shoals,reef flanks,etc..The paper deals emphatically with the sedimentology and diagenesis of the reef com-plex.