论文部分内容阅读
徐家围子断陷在晚侏罗世 -早白垩世期间从断陷边缘至断陷中心形成一系列的断阶带 ,控制断阶带形成的同沉积断层也分割了凸起带、斜坡带和凹陷带等次级盆地单元。徐家围子断陷的次级构造单元在断陷北部和南部存在差别。北部区由东、西两个半地堑组成 ,而南部区由 3个半地堑组成。每个半地堑一般是由盆缘凸起带、陡坡断阶带、凹陷带和缓坡或缓坡断阶带组成 ,半地堑之间为次级凸级。断阶带的发育控制了盆地自边缘至凹陷的地形 ,因此控制了沉积相类型与分布 ;同时断裂活动引发的或与断裂活动伴生的火山活动导致火山物质的盆地充填 ,改造或塑造盆地次级单元构造样式和盆地地形 ,因此也控制沉积相类型与分布。徐家围子断陷的断阶带控制了火山岩体和沉积相带的分布 ,这种控制作用受多种因素影响 ,并非单一机制所能解释。
During the Late Jurassic-Early Cretaceous, the Xujiaweizi faulted basin formed a series of fault-level belts from the margin of fault depression to the center of fault depression, and the synsedimentary faults formed by the control of fault-step belts also divided the raised belt, slope belt and Depression and other secondary basin units. The secondary tectonic units in the Xujiaweizi faulted depression differ in the northern and southern parts of the fault depression. The northern area consists of two and a half graben areas in the east and west, while the southern area consists of three and a half graben areas. Each half-graben is generally composed of basin margin belts, steep slope fault belts, depression belts and gentle slope or gentle slope fault belts, and the semi-graben is the secondary convex. The development of the fault zone controls the topography of the basin from the edge to the depression, thus controlling the type and distribution of sedimentary facies. At the same time, the volcanic activity caused by the fault activity or associated with the fault activity leads to the volcanic basin filling, rebuilding or shaping the secondary The cell structure pattern and basin topography also control the type and distribution of sedimentary facies. The fault-level belts in the Xujiaweizi rifting control the distribution of volcanic rock mass and sedimentary facies. The controlling effect is affected by many factors, which can not be explained by a single mechanism.