【摘要】 本文主要利用最新的钻井和三维地震资料对渤海海域莱州湾凹陷盐构造几何形态、形成演化及其控制机理进行分析。莱州湾凹陷沙河街组四段含有较厚的岩盐和膏盐层,并在KL11-2地区发生聚集隆起,形成典型的盐底辟(盐枕)构造。KL11-2地区盐构造外部形态在不同地区发生了明显变化,从南向北,逐渐由过成熟底辟向成熟底辟和盐枕变化,南部的盐构造已进入底辟后演化阶段,而北部的盐构造仍处于盐枕阶段。受盐体塑性流动影响,盐构造周缘还发育有盐撤凹陷和阶状反向断层等盐相关构造。KL11-2地区盐构造的形成主要受伸展作用、重力滑动、浮力、沉积差异负载、基底构造以及郯庐断裂带的走滑作用等因素影响,主控因素为伸展作用背景下的重力滑动作用,但郯庐断裂带的走滑作用对盐体的塑性流动及其最终定位也有重要的影响。更多还原

【Abstract】 Based on the new well and 3D seismic data,this paper mainly concerns the geometries and growth histories and controlling factors of the salt structures in the KL11-2 area of the Laizhouwan depression,offshore Bohai Bay Basin.In the Laizhouwan depression,the Sha-4 Member of the Paleogene Shahejie Formation attains thick salt and gypsum which have uplifted and formed salt diapir and pillow in the KL11-2 area.The geometries of the salt structures in the KL11-2 area change from the over-maturation diapir to maturation diapir and salt pillow along the S-N direction,which can indicate that the southern and northern salt structures belong to the post-diapir and salt pillow phases,respectively.Influenced by the viscous flowage and distortion of the halite,there are some salt-related structures,including salt-withdrawal minibasins and stepped counter-regional faults system,well developed in the adjacent areas surrounding the salt structures.The development of the salt structures in the KL11-2 area was controlled by the extensional stresses,gravitational gliding,buoyancy,differential loading and the basement structures,as well as the strike-slipping movement of the Tan-Lu fault,in which the gravitational gliding in the background of extensional stresses was the most important factors.In addition,the strike-slipping movement of the Tan-Lu fault should exert significance on the viscous flowage and final localization of the salt bodies in the Sha-4 Member of the Shahejie Formation in the KL11-2 area.更多还原