摘要
甘肃省阳山金矿田位于川、陕、甘交界的金三角地区,是近年发现的特大型微细浸染型金矿床。目前发现的4个矿段(床),均赋存于泥盆系三河口组浅变质碎屑岩、碳酸盐岩地层中。矿田受安昌河-观音坝断裂带控制,矿体产于断裂带内褶皱翼部的次级剪切带或断裂中。元素地球化学研究表明:Au、As、Hg、Bi等元素在阳山矿田表现出强烈富集的特征。矿石微量元素分析发现阳山金矿田成矿物质主要来源于岩浆岩。相关分析揭示矿区微量元素主要有Au-As-Sb-Hg和Ag-Mo-Zn两种组合,Au与Hg、As、W、Sb等元素呈明显正相关。空间上Au与Hg、As、W、Sb等具有明显共消长关系。综合分析认为阳山金矿成矿物质主要来源于岩浆岩;Au-Hg-As-W-Sb可作为找矿的指示元素。元素比值特征显示矿体整体剥蚀较浅,目前地表出露应为矿体头部或中上部,且由东向西剥蚀程度逐渐加深,反映向深部矿体应还有较大成矿远景。
The Yangshan gold deposit recently found in south Gansu province is a supper-large fine-grained, disseminated type deposit in China. Four ore segments found by now in the deposit all occurred in the Devonian low grade metamorphic sandstone and limestone. The ore occurrences are structurally controlled by the Anchanghe-Guanyinba fault zone and orebodies usually exist in the secondary shear zones and faults of the folds in the Anchanghe-Guanyinba fault zone. The orebodies in lenticular or veinlike forms are spatially related to a plagioclase granite. Pyrite and arsenopyrite are the main metallic minerals, and native gold can usually be seen in pyrite, arsenopyrite and clay minerals as micrograined inclusions (2～3μm). Trace elements analyses from samples from vertical and transverse sections of the deposit show strongly enriched Au, Hg, As, Bi and Sb in the ore and a positive correlation among the elements. This indicates that the Au, Hg, As, Bi and Sb together represents a major element association for the deposit. Moreover, the analyses suggest that ore-forming materials was derived from magmatic rocks and Au-Hg-As-W-Sb can be treated as an indicator for prospecting. We argue, by the ratios of some indicator elements that the ore deposit has been only eroded to a middle-upper level, and the denudation, from east to west, becomes stronger. Therefore, a much richer deposit could be seen at depth of the deposit.
出处
《西北地质》
CAS
CSCD
2006年第3期20-27,共8页
Northwestern Geology
基金
中国人民武装警察部队黄金指挥部专项基金资助项目(编号HJ0001)
关键词
甘肃省
阳山
金矿田
元素地球化学
微细浸染型
Gansu province
Yangshan
gold deposit
elemental geochemistry
fine-disseminated type
作者简介
袁士松(1977-),男,河南开封人,武警黄金地质研究所工程师,从事金矿地质研究工作.通信地址:065000,河北省廊坊市,武警黄金地质研究所成矿预测室. E-mail:yuan496111@yahoo.com.cn
