Analysis of micro-tectonic and mechanism of quartz tectonite in Yangla large-scale copper deposit in West Yunnan

The structure and fabric of tectonite directly record the deformation or flowage of rock. According to the micro analysis of quartz structure from Yangla copper district in West Yunnan, the authors think that : (1) the tectonic activities of SN and NW striking are intenser than others;(2) the NE striking tectonic activity becomes intenser near orebody 2 and NWW striking tectonic activity can be observed apparently at north part of the district. The dynamic analysis indicates that the direction of maximum principal stress in this district is NW SE and NE striking during the late period. EW striking maximum principal stress acted continuously, which lead to the brittle and ductile deformation of rocks. The pattern of preferred orientation of quartz optic axis and Fulin parameter k show that the flaser is the main deformation.