Sedimentary evolution of the Guanzhuang Formation in the Xinwen depression, Shandong

With the aid of sequence stratigraphic and sedimentological principles, the types, vertical evolution and planar distribution of sedimentary facies are dealt with on the basis of field observations of sedimentary structures, thin section examination and grain size analysis for the Guanzhuang Formation in the Xinwen depression, Shandong. The three types of sedimentary facies are recognized including the alluvial fan, braided stream and lake facies, and two sedimentary systems are developed including alluvial fan-braided stream-lake and alluvial fan depositional systems in an ascending order in the Guanzhuang Formation. The sedimentary evolution covered the alluvial fan and braided stream deposits during the early stage, lake deposits during the middle stage and alluvial fan progradational deposits during the late stage.