Tectonic-sedimentary evolution of the first and second members of the Kongdian Formation in southern Kongdian,Huanghua depression

The sedimentary facies analysis and Palaeogeographic reconstruction have disclosed that the Kongdian uplift-Kongdian tectonic zone was initiated during the early stage of the deposition of the first member of the Kongdian Formation,and came into being during the late stage of the deposition of the first member of the Kongdian Formation.The southern part of Kongdian was once a down-warped basin during the deposition of the second member of the Kongdian Formation,whereas during the deposition of the first member of the Kongdian Formation,this area was in the subsidence stage and the Kongdian uplift-Kongdian tectonic zone was a slowly subsiding zone rather than a relatively uplifted area.