滇西羊拉大型铜矿床石英构造岩微观构造与动力学分析

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

构造岩的构造和组构是变形运动亦即岩石流动的直接记录。作者对滇西羊拉铜矿区的石英构造岩进行了微观分析,认为矿区内的南北向、北西向构造活动较强,北东向构造活动近岩体增强,北西西向构造活动在矿区北部有较强的显示。动力学分析表明,矿区最大主应力方向晚期为北西—南东向和北东向,东西向主压应力断续作用,导致岩石的脆性和韧性变形,石英光轴优选方位形式及弗林指数k值的测算均说明变形方式以压扁为主。

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.