摘要
北衙金矿位于大理州鹤庆县北衙乡,为哀牢山。一金砂江富碱侵入岩带的组成部分。金矿在时、空分布及成因上都与燕山晚期。喜山期富碱斑岩密切相关。金矿体按产出特征可以分为四种类型,即受接触带控制的矿体、受构造破碎带控制的矿体、受层间裂隙控制的矿体和受岩相古地理控制的古风化壳矿体。原生矿体主要形成于中温热液阶段,黄铁矿等为主要载金矿物。矿区独特的地质条件使氧化带深度可达400米,矿体遭受强烈表生氧化并形成金的次生富集。金主要来源于岩浆热液,具有深源浅成的特点。
Located in western part of Yunnan Province,Beiya porphyry gold deposit is a constituent part of the A ilaoshan-Jinshajiang alkali-rich intrution zone that stretches south-north for over 2000km.The gold deposit connected spacially and genetically with porphyry of Himalayan movement.Orebodies occured mainly in four favorable structural situations,i.e.contact zone of the porphyry stocks,fractrured zone inside the porphyry rock,bedding voids in country rocks and ancient karst depressions.Studies show that the porphyry resulted from the differentiation on hypogene magma and formed in a relatively near surface environment.A signifisant enrichment of gold occured in the process of supergene oxidation.Oxidation zone could develop as deep as 400 metres.Pyrite is the principal primary gold-bearing mineral and gold is presently hosted mainly in limonite.
