大冶铁矿区多期构造变形分析及成矿意义

Multi Stage Structural Deformation Analysis and Metallogenic Significance in the Daye Iron Ore Area

大冶铁矿区位于长江中下游成矿带的鄂东南矿集区,叠加构造变形对铁矿床的矿化特征、成矿岩体的侵位、岩体和矿体的分布等有重要的控制作用。本文研究表明大冶铁山矿区有4期构造变形,D1期以NW、NWW走向断裂为特征,属于成矿前构造,奠定了研究区基本的构造格局,控制了研究区花岗岩岩体侵位、成矿热液的迁移和沉淀;D2期发育近N-S向的断层和褶皱,D3期形成近N-S或NNE向的伸展正断层。D2和D3期为成矿期构造,与矽卡岩化蚀变关系密切。D4期发育NE向右行走滑断层,属于成矿后构造,对矿体和蚀变围岩有改造作用,影响勘探实践。

The Daye iron ore area is located in the southeast Hubei ore concentration area of the Middle-Lower Reaches of the Yangtze River metallogenic belt.Its superimposed structural deformation plays an important role for the mineralization of iron ore deposits,the emplacement of ore-forming intrusions,and the distribution of both intrusions and ore bodies.There are four stages of structural deformation in the Tieshan mining area of Daye.The stage D1 is characterized by NW and NWW trending faults.They are pre-metallogenic structure establish the basic structural framework of the study area and controls the emplacement of granite,migration and precipitation of ore-forming hydrothermal solution.The stage D2 developed N-S trending faults and folds,and the stage D3 formed N-S or NNE trending extensional normal faults.The structures of the D2 and D3 stages are metallogenic structures and closely related to skarnization.The D4 stage developed NE-trending dextral strike-slip fault of post-metallogenic structure,which can reconstruct both the ore body and altered wall-rock and affect the exploration.