安徽繁昌地区古构造应力场及其演化特征研究

安徽繁昌地区是长江中下游铜-铁-金多金属成矿带的重要组成部分,区内构造控矿作用明显。对区内的褶皱、断裂和节理进行了野外调研和实地测量,并通过变形特征观察和构造配套分析,确定了繁昌地区多期次构造活动的主应力方向,即主压应力方向依次为:前印支期的EW向和SN向、印支期的NNW向、燕山早期的EW向、燕山晚期的NWW向以及喜山期的NE向和EW向。在此基础上,初步分析了该地区的构造演化特征,并指出从印支期到燕山晚期为主要的构造演化阶段。

Research on Palaeotectonic Stress Field and Its Evolution in Fanchang Area, Anhui Province

Fanchang area is an important segment of the Lower and Middle Yangtze iron-copper-gold metallogenic belt,and the ore deposits are evidently controlled by structures.Field investigation and measurement have been carried out on the folds,faults and joints in this area,with determination on the principal stress directions of the multiphase structural activities through deformation characteristics observation and structural set analysis.The directions of the main palaeotectonic stress fields were EW and SN during pre-Indosinian,NNW during Indosinian,EW during early Yanshanian,NWW during late Yanshanian,NE and EW during Himalayan period.On the basis of the study,an analysis has been completed on the evolution of palaeotectonic stress field in the Fanchang area.Furthermore,it shows that the main tectonic evolution was from Indosinian to late Yanshanian.