阿尔金断裂带中段区域新构造应力场分析

ANALYSIS OF NEOTECTONIC STRESS FIELD IN AREA OF THE CENTRAL SEGMENT OF ALTUN FAULT ZONE,CHINA

本文采用由断层擦痕资料反演构造应力张量的方法估算出阿尔金断裂带中段区域自上新世以来的两期主要构造作用:第Ⅰ期,上新世至早更新世,构造应力张量的最大主应力方向为近SN向,造成阿尔金断裂以逆断层运动为主,兼有左旋滑动;第Ⅱ期,早更新世末期至今,构造应力张量的最大主应力方向为NE—SW,造成阿尔金断裂以左旋走滑运动为主,兼有逆断层运动分量。

In this paper, a method of determination of principal stress axes from field measurements of the slickensides is used to study the two phases of tectonic stress of the region since the Pliocene. The first, from Pliocene to early-Pleistocene, the maximum principal stress acted in the direction of nearly N-S, resulted in that the Altun fault had been dominantly thrusting with sinistral; the second, from late of early-Pleistocene to the present, the maximum principal stress acted in the direction of NE-SW, led that the Altun fault moved mainly in the way of thrust-sinistral slip.