潜江凹陷潜北断裂带构造特征及演化史

摘要

潜北地区结构复杂,毗邻生烃洼陷,是潜江凹陷重要的油气资源接替区块,凹陷北部的潜北边界断层的主要活动在潜江组沉积时期.利用三维精细构造解释成果,解剖潜北断裂带,从剖面和平面总结潜北断裂带中段构造特征.潜北断裂带纵向上存在3个区分层,把构造活动划分成了四个时期;平面上可以划分为3段,西段发育阶梯断层,中段发育荆沙红墙,东段表现为犁型正断层.依据断裂带构造特征可以把潜北断层活动期次划分为走滑拉分、断陷、坳陷、张扭4个期次.根据潜江凹陷演化过程说明了现今上升盘曾经沉积过潜江组,解决了红墙的成因及其归属问题.%The tectonic features of Qianbei are complex,where is adjacent to the depression,and it's also a very important backup exploration district.Qianbei Fault is the boundary of Qianjiang depression in the north,and it was active at Qianjiang formation stage.By using the conclusion of elaborate structure interpretation,it analyzed and summarized the structural characteristics of the middle Qianbei belt.There are three bounds existing in vertical intervals,which divides the tectonic activity into four periods.Also,the plane can be divided into three sections,the western developmental ladder faults,the middle section of Jingsha red wall and the eastern section as plow faults.The period of the fault movement can be divided into four stage:slip-separate,rift,sag,transtensional reform,as correspond to the period of the depression form,expanding,fading,reform.