湖北大悟大坡顶金矿床金矿物特征  

Characteristics of Gold-bearing Minerals from the Dapoding Gold Deposit in Dawu,Hubei Province

作　　者：杜登文[1] 洪汉烈[1] 徐志强[2] 李荣彪[1] 胡远清[2] 王粉丽[1] 李祖春[2] 

机构地区：[1]中国地质大学地球科学学院,武汉430074 [2]湖北省鄂东北地质大队,湖北孝感432000

出　　处：《地质科技情报》2008年第4期55-60,共6页Geological Science and Technology Information

基　　金：国土资源部资助项目"湖北省大悟县大坡顶金矿普查"(2006-293)

摘　　要：利用光薄片的显微观察、X荧光光谱分析、X射线衍射分析、电子探针显微分析以及等离子光谱分析等方法，对湖北大悟大坡顶金矿床矿石中金的矿物学特征进行深入研究，结果表明，矿石中金以银金矿的形式产出，金矿物颗粒的大小多在5～150μm间；银金矿物颗粒一般呈液滴状或其他的不规则形状充填于黄铁矿、石英颗粒的裂隙或这些矿物颗粒的间隙，少量被包裹在硫化物矿物、石英颗粒之中。金矿物成色较低，最低为736，最高为860，平均金矿物成色为784。金矿物的低成色特征说明这些金矿物形成于浅部；共生黄铁矿中含有较高的Co和较低的Ni指示成矿物质与深部岩浆作用有关．而从大别群变质岩围岩具有较高的金的背景值指示成矿元素金可能来源于岩浆活动造成的金的活化迁移。Gold mineralogy from the Dapoding gold deposit in Dawu, Hubei Province, is investigated by means of optical microscopy, X-ray fluorescent analysis, X-ray diffraction, electron probe microscopy analysis, and inductively coupled plasma atomic emission spectrometry. The results show that gold occurs as electrum, with particle size raging from 5 to 150μm. The morphologies of the Dapoding electrum are usually present as droplet outline or irregular outline, electrum observation indicates that the gold is mainly filled in the fissures of pyrite and quartz crystals or in the interstitial space of the grains, and/or included in sulfide and quartz particles. The fineness of the electrum ranges from 736 to 860, with an average of 784. The relative low fineness of the electrum grains reflects that the electrum was formed in a shallow depth. In addition, there is more Co relative to Ni in pyrite, suggesting that the source of mineralized solution is derived from the magmatism, and gold derived from the surrounding Dabie metamorphic rocks.

关 键 词：大坡顶金矿床 银金矿 黄铁矿 电子探针 

分 类 号：P578.11[天文地球—矿物学]