黄骅盆地孔西构造带的构造演化特征

通过平衡剖面技术复原古构造演化 ,并结合区域构造分析 ,可将孔西构造带的发育过程大致分为三个构造变形阶段 :晚三叠世末期为挤压褶皱变形期 ;晚三叠世沉积后至侏罗系沉积前为逆冲构造变形期 ;早—中侏罗世为逆冲构造“轻度”渐进变形期。晚侏罗世以后 ,区域构造作用发生反转。随着晚侏罗—早白垩世、早第三纪裂陷盆地的发育 ,孔西构造带作为潜山构造被掩埋。裂陷盆地时期的伸展构造对孔西构造带前第三系的逆冲构造基本上没有大的改造

TECTONIC EVOLUTION OF THE KONGXI STRUCTURAL BELT

The evolution of the Kongxi structural belt can be mainly divided into three periods by using the balanced profile technique to restore paleostructure during the Middle Late Triassic. The gentle fold deformation developed in Paleozoic and the detachment thrust maybe emerged as a result of the gently swelling shortness produced in Ordovician System during the late Triassic end or before Jurassic system deposited . The thrust structure deformed in the Permo Carboniferous strata, and then, the erosion happened in the top of Paleozoic. During Jurassic and Cretaceous, the thrust belt was covered with terrigenous deposits and became a "buried hill" in the topography. In the Lower Middle Jurassic the thrust structure lightly gradually deformed. When it deposited, the front of some thrust faults permeated into Lower Middle Jurassic. After the Lower Middle Jurassic deposited, regional structure inversed, during the Upper Jurassic Lower Cretaceous deposited in the extensional basin. After that, a Paleogene rifting basin - Huanghua basin was superposed on the buried hill. The Kongxi structural belt is comprised in the Cangdong normal fault, the Kongxi thrust, the normal fault of the west slope of the Kongdian relief and fault bend synclines.