内蒙大水清金矿带交代作用及其与金矿化关系  

Hydrothermal Alteration in Dashuiqing Gold Ore Belt,Nei Mongol,China and Its Relation to Gold Minerlization

作　　者：郑学正[1] 关鸿[1] 张魁武[1] 李达周[1] 李秀云[1] 

机构地区：[1]中国科学院地质研究所

出　　处：《岩石学报》1996年第3期424-433,共10页Acta Petrologica Sinica

摘　　要：大水清金矿带是华北克拉通中有代表性的改造型绿岩金矿之一。它产于前东武纪绿岩地体中安家营子石英二长岩体内外接触带附近的剪切带中。金矿化交代主要受后阶段张性脆裂控制，而剪切带早阶段韧性剪切作用无明显矿化交代，后者主要为成矿交代提供有益的江游交代构造环，境即成矿交代蚀变作用和剪切带同步的两阶段演化模式。大水清金矿带的交代作用有四个阶段：即用长石化阶段，绿泥石化阶段，黄铁绢英岩化和石英－硫化物阶段以及石英－碳酸盐化阶段。第三阶段由五个亚阶段组成：即黄铁绢英岩化和强硅化－强黄铁矿化，石英－多金属硫化物交代，石英－贫扶矿充填交代和细粒黄铁矿充填交代。其中前四个亚阶段是本区金的主要成矿期．当韧性剪切转化为张性脆裂时产生的骤然扩容和伴随发生的交代体系转变为富硅体系的钾交代和石英－硫化物交代是金矿成矿的关键。本文还研究和探讨了该金矿成矿交代流体的性质及交代的物理化学环境。The Dashuiqing gold ore belt is one of the reworked greenstone gold ore belts.It occurs in a shear zone near the contact between the Anjiavingzi Quartz monzonite they and Precambrian greenstone.There ane fwo stages of evolution of the shear zone:ductile shear in early stage and extention crush in the later.Hydrothermal alteration related to gold mineralization in the belt only occurs in the later stage, and no any gold mineralization occurred in the former stage. There are four stages of hydrothermal alteration in the Dashuiqing goldore belt: albitization in the first stage,chlorite replacement (with some pyrite) in the second stage, the main gold mineralization only in the third stage, which is composed of five substag6s: sericite-quartz-pyrite assemblage, massive quartz--pyrite, quartz-polymetal sulphides, veined pyrite-quartz and fine-grained pyrite,respectively, and quartz-carbonite assemblage in final stage.The main gold ore formation period is the early four substages of the third stage.Their physico-chemical conditions for the hydrothermal alteration are discussed in the paper.

关 键 词：金矿床 矿化 热水 交代作用 金矿带 

分 类 号：P618.510.5[天文地球—矿床学]