东坪金矿主要地质特征及控矿条件

东坪金矿产于水泉沟偏碱性杂岩体与太古宇桑干群变质岩之内接触带，矿石工业类型为石英脉和蚀变岩型，以前者为主.矿脉带走向为NNE，主要载金矿物为石英、黄铁矿、镜铁矿、黄铜矿和碲金矿，金成色937~990，矿化蚀变主要是钾长石化和硅化；肉红色钾长石化是东坪金矿乃至赋存于水泉沟杂岩体中所有金矿的典型特征.矿化共分5个阶段，其中第2、3两个阶段，即镜铁矿-自然金-石英阶段和多金属硫化物-自然金-石英阶段为主要成矿阶段.水泉沟杂岩体在东坪金矿成矿过程中，不仅提供了热动力，而且提供了成矿物质和矿化剂；太古宙桑干群涧沟河组提供了部分成矿物质，近E-W向尚义-崇礼-赤诚深大断裂控制了水泉沟金矿田的产出，而NNE和NW向两组裂隙则控制了东坪金矿矿体的产出.

GEOLOGICAL CHARACTERISTICS AND ORE CONTROLLING CONDITIONS OF DONGPING GOLD DEPOSIT

Dongping gold deposit is located at the internal contact zone between the Shuiquangou weak alkaline complex and the metamorphic rocks of Archeozoic Sanggan group The ores consist of two industrial types,i e ,quartz vein and alteration rock types,but the former is dominated The ore vein zones strike in north northeast Quartz,pyrite,specularite,chalcopyrite and calaverite are gold carrying minerals Gold fineness ranges from 937 to 990 K feldspathization and silicification are dominant mineralizing alteration Red colored K feldsparthization is the typical character of Dongping and other gold deposits occurring in the Shuiquangou complex The mineralization can be devided into 5 stages,of which the second and third stages,i e ,specularite native gold quartz stage and polymetallic sulphides native gold quartz stage,are of two main mineralizing stages Shuiquangou complex supplied not only hot source,but also mineralized materials and mineralizer during mineralization Approximately E W trending deep large Shangyi Chongli Chicheng fault controls the occurrence of Shuiquangou gold orefield whereas two groups of NNE and NW trending fissures control the occurrence of the orebodies of Dongping gold deposit