前河地区正长斑岩构造蚀变岩型金矿围岩及容矿岩石特征

正长斑岩构造蚀变岩型金矿容矿岩石和近矿围岩的原岩属正长斑岩，它先后发生糜棱岩化，角砾岩化、碎裂岩化，加上后期多种蚀变作用的叠置，使其变得较为复杂。成矿早期蚀变为黑云母化、钾长石化；成矿期主要是黄铁绢英岩化、黄铁萤石泥英岩化；而成岩后期则主要为碳酸盐化。由于多期构造和蚀变的叠置，容矿和近矿糜棱岩外观很难辨认，只有据显微镜下见到的一些残迹和变余的糜棱岩残体来恢复原岩。矿体间接围岩原岩为玄武安山岩，早期曾受接触变质变为角岩。主要由普通角闪石和斜长石组成。可见变余原岩结构构造，后来又接受一系列构造和蚀变作用，主要是黑云母化、绿泥石化，次为碳酸盐化、钾（钠）长石化。但在其形成的构造蚀变岩中，金含量一般未达工业品级

THE CHARACTERISTICS OF THE WALL ROCK AND HOST ROCK OF THE ORTHOPHYRIC TECTONIC ALTERED ROCK TYPE GOLD DEPOSITS IN QIANHE AREA

The protolish of host rocks and near deposits wall rocks of the orthophyric tectonic altered rock type gold deposits was the orthophyre.It became more complication as underwent the mylonitization,brecciation,catagenesis and the late different alterations.The early alterations of mineralization were the biotitization and potassium feldsparization,and mainly the pyritized phyllite and pyritized fluoritization argillization in the mineralization period,and but the carbonatization in the postore period.The aspect of the hosted and near ore mylonite is hardly identified because of the overprints of multiphase tectonics and alterations.Only on the ground of some vestiges and relics of the blastomylonite seen under a microscope can be they recovered and discriminated.The protolish of indirect wall rock of the orebody is basaltic andesite,which undergoing the contact metamorphism changed into the hornfels consisting of hornblende and plagioclase in the early period.But the texture and structure of the blasted initial rock can be identified.Then it yet underwent a series of the tectonic processes and alterations.Its alterations were mainly the biotitization,chloritization,and the second the carbonatization,potassium feldsparization and albitization.But,in the tectonic altered rocks consisted above altered minerals,the gold bearing content has common not attained to the pay grade.