鄂西建始断裂工程活动性评价

本文通过对鄂西建始断裂的几何分形结构和变形结构的分析，结合其新构造活动、现今构造活动特征，探讨断裂的运动学和动力学特征以及形成演化过程。建始断裂分段特征明显，在燕山主期以逆冲作用为主，在燕山晚期以伸展作用为其主要活动特征，在喜马拉雅期则表现为平面左旋剪切活动；在新构造活动期以右旋剪切为主，北段构造活动性相对较强，中段和南段构造活动性相对较弱。断裂在Ｑ１－Ｑ２时期有过明显的活动，其最新活动测试年龄为

ENGINEERING EVALUATION OF ACTIVITY OF JIANSHI FAULT IN WESTERN HUBEI PROVINCE

A detailed study of the fractal geometry deformation structure, as well as the latest and present tectonic activity of Jianshi fault has been made to bring to light the kinematic and dynamic characteristics of the fault and its evolution.It was a thrust fault in the main episode of the Yanshanian epoch, an extension fault in the late Yanshanian and a sinistral strike slip fault in the Himalayan.In the Neogene, the northern segment of the fault underwent a stronger dextral strike slip than its central and southern segments.In Q₁-Q₂ it was once active, and age of the latest activity is determined to be about 197.6±160 thousand years and is presently weak in seismicity.It is therefore concluded that the Jianshi fault is an in active fault, in the engineering sense, causing no essential harm to the nearby hydropower works.