内蒙古获各琦多金属矿区新元古代渣尔泰群变质—变形及硫化物矿床对变质作用改造的响应

The Metamorphism and Deformation of the Neoproterozoic Zhaertai Group and Transformation Response to the Sulfides Ore-deposit of Huogeqi CopperZinc Polymetallic Deposit in Inner Mongolia

获各琦矿区新元古代渣尔泰群变质—变形作用强烈,后期变质—变形作用使矿体接受了多期次的变形改造。露头构造解析、显微构造观察以及变形石英EBSD组构分析揭示出矿区主要经历了2期不同温压条件下的剪切作用,第一期为NW-SE向高温剪切作用,变形温度在600℃左右;第二期为NE-SW向低温剪切作用,变形温度较低。依据硫化物显微组构等特征分析,初步认为矿体遭受后期区域变形改造明显,矿体的贫化和富集是变质—变形作用导致硫化物活化、迁移和重新就位的结果。

Through analysis from outcrop to microscopic scales,and quartz c-axis fabrics,we consider the Neoproterozoic rocks in the Huogeqi ore field experienced multi-phase deformation and metamorphism.Two phases of deformation contribute to the different structural characteristics in northern,central and southern belts.The first phase of deformation is characterized by NW-SE shearing at deformation temperature at about 600 ℃.The second phase of deformation is evidenced by NE-SW shearing at ralatively low temperatures.Microscopic features of the deformed sulfides indicate that the orebodies were transformed by the multi-phase deformation.Enrichment and depletion of the orebody may result from the physical remobilization caused by the shearing.