渤海中、新生代盆地构造活动与沉积作用的时空关系

渤海盆地主要构造特征是盆地内广泛发育同沉积生长断裂。这些断裂绝大多数是张性或剪张性,主要构造类型有伸展构造、走滑构造和反转构造等。渤海中、新生代盆地发育巨厚的陆相沉积。第三纪是渤海中、新生代盆地的主要断陷成盆时期,下第三系沙河街组四段孔店组零星分布,残缺不全,盆地狭小;沙河街组三段东营组沉积广泛,盆地变宽。上第三系十分发育,并在渤中地区形成盆地的沉降中心。从构造沉积环境图分析,渤海西部的沉积相受NW向断裂控制,而东部的沉积相受NNE向断裂控制。渤海主要控盆断层的生长指数反映渤海中、新生代主要有三期断层活动高峰期:中生代、沙河街组二、三段沉积期和东营期,其中沙河街组三段沉积期是构造活动和沉积作用最强烈的时期。

SPACE-TIME RELATIONSHIP BETWEEN TECTONICS AND SEDIMENTATION OF MESO-CENOZOIC BOHAI BASIN

The main structural characteristics of the Bohai Basin is that synsedimentary growth faults widely developed in the basin.These faults are mainly tensile and tenso shear ones and the structural types includes extensional,strike slip and inversion structures.Great thickness of continental deposits developed in the Meo Cenozoic Bohai Basin.The Tertiary Period was the principal fault depressed stage.The fourth member of the Shahejie Formation and the Kongdian Formation of the Lower Tertiary scattered incompletely and the basin was small and narrow;She 3 member and the Dongying Formation were distributed extinsively and the basin extended wider.The Upper Tertiary System developed well,the depocenter was formed in the central part of the basin.According to the analysis of structural sedimentary environment,the sedimentry facies of the west of Bohai Basin was controlled by NW directional faults while that of the east region was controlled by NNE directional structures.The major growth index of faults that controlled the the basin indicates that there were three peak stages of fault activities:the Mesozoic,Sha 3 sedimentary stage and Dongying stage.The Sha 3 sedimentary stage was the most intensive stage both for tectonic activities and sedimentation.