论文部分内容阅读
渤海西部海域沙垒田凸起为继承性的古凸起,凸起边缘主要受北西向先存断裂及北东向早期断裂控制,根据控凹主断裂特征以及主断裂、早期同沉积断裂和伴生断裂之间的组合关系,古凸起边缘可划分为同向断阶型边缘、大型低角度正断层控制的缓坡边缘、平直状正断层控制的缓坡边缘、板式正断层控制的陡坡边缘及铲式正断层控制的陡坡边缘和座椅式正断层控制的陡坡边缘等6种。受边缘断裂坡折地貌影响,不同类型凸起边缘沉积相展布和纵向演化具有一定的规律性:同向断阶型凸起边缘,早期盆缘坡折之下发育低位扇三角洲,晚期发育辫状河三角洲前缘加厚带,分隔凸起与缓坡的晚期主干断裂早期控制高位扇三角洲,晚期控制了辫状河三角洲的发育;大型低角度正断层之上发育的同沉积断层控制了沙三段强裂陷期低位扇三角洲、浊积扇的沉积,之后发育缓坡辫状河三角洲—滨浅湖;对于平直状同沉积断层控制的缓坡边缘,沙河街组沉积时期发育缓坡背景下的水进和高位辫状河三角洲,东营组沉积时受断裂坡折影响,坡折之下发育辫状河三角洲前缘加厚带,之上发育辫状河三角洲平原和小型沟谷充填。陡坡边缘沉积充填在垂向上具有分层结构,由早期冲积扇或扇三角洲向辫状河三角洲演变,陡坡坡折控制低位扇三角洲的发育,坡折之上发育沟谷充填和辫状河三角洲平原沉积。
The Shapotian uplift in the western Bohai Sea is a successional paleo-bump. The raised edge is mainly controlled by the NW-trending pre-existing faults and the NE-trending early faults. According to the features of the main controlled faults and main faults and the early synsedimentary faults and associated The paleo-convex edges can be divided into the same-direction fault-type edge, gentle slope edge controlled by large low-angle normal fault, gentle slope edge controlled by straight normal fault, steep slope controlled by plate normal fault and shovel 6 types of steep slope controlled by normal faults and steep slope controlled by seat normal faults. Affected by the fractured slope at the margin, the sedimentary facies distribution and the longitudinal evolution of different types of convex edges have certain regularities: the same-direction fault-type convex edge, lowstand fan delta under early basin margin slope collapse, In the delta front of the delta-shaped river, the early main faults that separated the bulge and the gentle slope controlled the fan delta early and controlled the development of the braided delta in late stage. The same sedimentary fault developed above the large-scale low-angle normal fault controlled the sand-three Sedimentation of low fan delta and turbidite fan in the Duanqiang rifting stage followed by development of gentle braided river delta-shallow shore lake. For gentle slope margin controlled by flat-shaped synsedimentary faults, water in the sedimentation stage of Shahejie Formation is developing The braided delta and the Dongying Formation in the upper and lower braided delta are affected by the fracture slope, and the braided river delta front is thicker below the slope fold. On top of this, braided river delta plain and small valley fill are developed. Sedimentary filling on the steep slope has a vertically stratified structure that evolved from early alluvial fan or fan delta to braided river delta, steep slope slope control the development of low fan delta, valley filling and braided delta deposition .