大兴安岭北部恩和哈达中侏罗统绣峰组韧性剪切变形

THE ENGH HAD DUCTILE SHEAR DEFORMATION OF MIDDLE JURASSIC XIUFENG FORMATION IN THE NORTHERN PART OF DAXINGANLING, INNER MONGOLIA

大兴安岭北部恩和哈达韧性剪切变形带发育于漠河盆地中侏罗统绣峰组砂砾岩地层中,其几何学、运动学、动力学等特征显示该韧性变形带为由北西向南东近水平右行斜向逆冲型剪切带.在近南北挤压条件下,晚侏罗世—早白垩世同构造侵位的中酸性岩浆岩为之提供高温热源,促使绣峰组砂砾岩在浅表层发生顺层-切层韧性剪切变形.与之同时,强烈韧性变形促使砂砾岩中金发生活化迁移,韧性变形带及派生的脆性构造成为成矿流体的重要运移通道和储矿空间.

The Engh Had ductile shear zone occurs in the glutenite of Middle Jurassic Xiufeng formation in Mohe basin in the northern part of Daxinganling Mountains.The geometric,kinematic and dynamic characteristics show that the ductile shear zone is dextrally slanted thrust shear zone from northwest to southeast.In the condition of compression from south to north,with a heat source provided by the syntectonic acid intermediate magmatic rock, the ductile shear deformation took place in the glutenite of Xiufeng formation along or across layers.At the same time,the strong ductile deformation promoted the activation and migration of Au in the glutenites.The ductile deformation zone and derived brittle structures perform the transferring channels for ore forming fluid and space for ore deposition.