渤海湾盆地垦东凸起及邻区构造运动学

KINEMATICS ANALYSIS OF KENDONG UPLIFT AND ADJACENT REGION,BOHAI BAY BASIN

渤海湾盆地中南部垦东地区是一个新的油气勘探领域。为了深入研究垦东凸起及邻区的构造特征与油气聚集规律,寻找有利圈闭,讨论了该地区的断块体运动类型,并对水平伸展运动和翘倾运动进行了分析。通过地质、地球物理综合研究,得出以下结论:①垦东凸起及邻区断块体运动的方式主要表现为水平方向的伸展运动、掀斜或旋转运动;②通过计算垦东凸起及邻区伸展系数、断层生长指数、断层落差以及绘制平衡剖面,反映出垦东凸起及周围凹陷构造演化活动具有断陷早期活动剧烈、断陷晚期逐步减弱并基本中止的特点;③垦东凸起及邻区翘倾运动的形成与发育受控于郯庐断裂带的走滑及伸展运动,经历了中古生界—孔店组单断、沙四段多个单断、沙三段—沙一段双断、新近系弱伸展坳陷或坳断的过程。

The Kendong Region is a new hydrocarbon exploration target in the central and southern Bohai Bay Basin.In order to study the tectonic characteristics and their bearing on hydrocarbon accumulation in the region for favorable traps,the types of block movement,especially the horizontal extensional movement and the tilting movement are carefully studied.Based on integrated geological and geophysical studies,the authors reached following conclusions.（1） The block movement in the Kendong Uplift and adjacent region is dominated by horizontal and extensional movement and tilting or rotating movement;（2） Through the study of extensional coefficient,fault growth index,fault throw and balanced cross section,it is revealed that the tectonic revolution in the Kendong Uplift and adjacent region is characterized by a strong movement in early stage and a weak movement in later stage;（3）The tilting movement in the region was controlled by the strike-slip and extensional movement of the Tanlu Fault,and had experienced four stages： single faulting in Mz-Ek,multiple single faulting in Es4,bilateral faulting in Es3-Es1,and weak extensional movement or dislocated down-warping in Neogene.