甘肃观音山金矿床地质特征及矿床成因  

Geological characteristics and origin of gold deposit in Gansu

作　　者：魏庆林[1] 

机构地区：[1]甘肃有色地质勘查局四队,甘肃张掖734012

出　　处：《桂林工学院学报》2004年第2期143-147,共5页Journal of Guilin University of Technology

基　　金：甘肃省国土资源厅勘查项目(6200009960061)

摘　　要：观音山金矿床产于下石炭统海相浅变质火山岩系内,主要含矿地层为下石炭统白山群下岩组绿泥石片岩,矿体严格受东西向的区域性大断裂和其旁侧的北北东向、北北西向及与之近于平行的次级断裂的控制.矿石类型有石英脉型和构造蚀变岩型:石英脉型矿化连续性差,品位高、变化大(w(Au)3 5×10-6～118×10-6),可见大量自然金,其粒度一般小于5mm;构造蚀变岩型主要由强裂蚀变的碎裂岩、超碎裂岩组成,矿化连续且稳定(w(Au)1 5×10-6～8×10-6),是该矿床的主要矿石类型.赋矿地层具明显的热水沉积特征,成矿物质主要来自地壳深部,为一沉积变质-热液叠加改造型金矿.The Guanyinshan gold deposit is hosted in low grade metamorphed marine volcanic rocks of lower carboniferous. Major ore-bearing strata consist of chlorite schist of Xiayan Formation, Baishan Group, lower carboniferous. Ore bodies are strictly controlled by E-W regional fracture and adjacent NNE,NNW second-order fractures. There are two types of ore: quartz vein type and structurally altered rock type. The quartz vein type is characterized by high grade(Au=3.5×10^(-6)～118×10^(-6)) and poor continuity. Large amount of natural gold can be identified with grain size less than 5 mm. The structurally altered rock type is composed of cataclastic or super-cataclastic fault rock. It is characterized by reasonable grade(Au=1.5×10^(-6)～8×10^(-6)) and good continuity. The ore-bearing strata are formed in hot spring sedimentary environment. The ore-forming materials come from deep crust. Guanyinshan gold deposit is metamophsed sedimentary deposit superimposed by hydrothermal alteration.

关 键 词：金矿床 地质特征 矿床成因 观音山 甘肃 

分 类 号：P618.51[天文地球—矿床学]