UNCONFORMITY DISTRIBUTION AND TECTONIC MOVEMENT IN THE WESTERN AREA OF THE MANJIAER DEPRESSION

Based on drilling,seismic and surface outcrop data,S-bottom,C-bottom,C₁ b-bottom,T-bottom,J-bottom and K-bottom six major planes of unconformity are recognized in the sedimentary cover of West Manjiaer area.The characteristics of tectonic movement represented by these planes of unconformity and their effects on the tectonic features and sedimentation of West Manjiaer area are discussed.It is considered that there are two episodes of the Early Hercynian movement in West Manjiaer area even in the whole Tarim Basin which formed two major unconformities.One is the Early Hercynian movement of Ⅰ episode which happened at the end of the Devonian and formed the unconformity of C-bottom.The other is the Early Hercynian movement of Ⅱ episode which happeded after Donghe sandstone sedimentation and formed the unconformity of C₁ b-bottom.It is also considered that the Indosinian movement represented by J bottom unconformity has important influence on the tectonic features of West Manjiaer area.It terminated the long term developing history of the Lunnan Paleouplift since the Early Paleozoic,and made it possible to form the embryonic Hadexun Uplift.