断陷湖盆陡坡带砂砾岩体分布规律及控制因素——以渤海湾盆地济阳坳陷车镇凹陷为例

Distribution and controlling factors of glutinite bodies in the actic region of a rift basin: an example from Chezhen Sag,Bohai Bay Basin

基于济阳坳陷车镇凹陷的地质、钻井、地球物理资料,对断陷湖盆陡坡带砂砾岩的分布规律和控制因素进行了系统分析,总结其地质规律。断陷伸展湖盆陡坡带上的砂砾岩体具有"平面分带、垂向分期、持续后退、继承性强"的分布特征。陡坡带的断裂结构、构造转换带、古地貌和复合基准面是影响砂砾岩体空间分布的主要因素,其中,控盆边界断层的几何形态、构造活动特点控制了盆地层序地层的构型特征;应力减弱的构造转换带控制了入盆古水系的走向及物源入口;基底沉降和隆升、同生断裂强度及断面产状等因素影响下形成的古地貌控制了入盆砂体的平面展布;由不同时期不同级别基准面所形成的复合基准面控制了砂砾岩体发育层位。

The geologic, drilling and geophysical data of the Chezhen Sag, Jiyang Depression, are used to investigate the distribution rules and controlling factors of glutinites in the actic region of a rift basin. Planar strips, vertical stages, continuous backpedal and strong succession are the characteristics of the glutinite body distribution in a rift extensional basin. The fault structures, tectonic transform zones, paleo-geomorphology and complex base levels in the actic region are the key factors controlling the filling and distribution of glutinite bodies. The geometry and structural movements of the basin-controlling boundary faults dominate the sequence configuration, the tectonic transform zone with weak stress is the master of the inflow ancestral current direction and source entrance, the paleo-geomorphology decided by basement subsidence and rising, fault movement intensity and occurrence plays a key role in the sandstone distribution, and the scale and strata of the glutinite bodies is under the control of complex base levels in different stages.