Abstract:

A reef situated 500m southesast of Keziliqiman, Pishal County, Xinjiang belongs to theKeziliqiman Formation of the Lower Permian. The reef core is 57.6m thick and its maximumexposure is up to 300m across. The reef flank, consisting of grain limestone, middle to thinbedded marly limestbne and bioclactic limestone, is connected with the reef core by interfingering.Reef-building organisms consist chiefly of colonial tetracorals, Sphinctozoas, blue-greenalgae and Tubiphytes and then bryozoans, Inozoas and hydrozoans. Most of the organismshave kept their original growth patterns. The orgamisms could be divided into 4 micro-factessuch as baffle limestone, baffle-skeletal limestone, bound limestone and reef debris limestoneand 4 stages of reef evolution correspondingly based on the vertical zonation.