张扭性边界大断层上盘的构造分布模式

Structure distribution pattern at the upthrow side of a tension-torsional boundary fault.

通过区域应力场的分析,对华北盆地南部多序次的张扭性边界大断层的形成机制、断裂系统及其扭动方向有了明确的认识。根据张扭性边界大断层往往以弧形断裂形式出现的特点,将区域扭动和应力方向与边界大断层的不同走向段进行了相关分析,提出此类断层存在三个主要应力分布区:即反扭强张区、顺扭减张区和平行强扭区。依据上述相关分析结果,建立了张扭性边界大断层上盘的构造分布模式:即张性负向构造一般分布在反扭强张区;扭性负向构造一般分布在平行强扭区;正向构造一般分布在顺扭减张区。利用这种构造分布模式,在张扭性边界大断层上盘可准确预测和发现各类地质构造,提高油气勘探的成功率。

The scientific analysis of regional stress field leads to clear understanding of the generation mechanism, faulting systems, and torsional directions of the tension-torsional boundary faults at the south part of North China basin. Having analysed the correlation between each boundary segment and regional torsion plus stress in terms of the fact that tension-torsional boundary fault is characterized by arc form, I have found that this kind of fault belt consists of three major stress areas: reverse-torsional strong-tensional area, torsional tension-reduced area and parallel strong torsional area. Using the correlation analysis result,I have put forward the following structure pattern at the upthrow side of a tension-torsional boundary fault: tensional negative structures usually occur in the reverse-torsional strong-tensional area, torsional negative structures ususlly in the parallel strong torsional area,and positive structures in torsional tension-reduced area. This structural distribution pattern allows prediction and discovery of various geological structures at the upthrow side of a tension- torsional boundary fault, thus raising the success rate of hydrocarbon exploration.