滇西羊拉铜矿矿床成因及成矿规律

Deposit Genesis and Metallogenic Regularity of Yangla Copper Deposit in Western Yunnan Province

羊拉铜矿床位于昌都—思茅地块与中咱微板块的结合部位,是加仁花岗岩带上羊拉—曲隆Cu(Pb-Zn-Ag)矿带中具有代表性的矿床之一。为进一步指导矿区深部及外围地质找矿工作,结合区内已有的地质研究成果,详细分析了区域成矿背景、矿床地质特征、成矿要素、成因机制,并深入探讨了地层岩性、构造及岩浆活动与成矿的关系。研究表明:①矿区主要出露志留系、泥盆系地层,其中志留系江边组、志留系里农组为主要的赋矿层位;②矿床受地层、构造控制作用显著,矿体整体规模、产状及厚度变化较大,沿倾向方向形态复杂多变,多呈层状、似层状、透镜状产出;③矿床主要受控于近SN向、NE向断裂组及层间破碎带,构造交汇部位矿化进一步富化;④矿床可划分为热水沉积成矿、岩浆热液成矿及构造热液改造成矿3个阶段,总体属热水沉积—热液改造型矿床。在上述研究的基础上,认为里农矿段西侧、路农矿段东侧及两者结合部位西北侧具有良好的找矿前景。

Yangla Copper Deposit is located in the binding site of Changdu-Simao Block and Zhongzan Block,which is one of the representative deposits in Yangla-Qulong Cu (Pb-Zn-Ag) metallogenic belt of Jiaren granite belt.In order to provide some reliable references for the deep and edge prospecting work of the mining area,based on the geological research results for the mining area,the regional metallogenic geological background,deposit geological characteristics,metallogenic factors,genetic mechanism and the relationship between formation lithology,structure,magmatic activity and mineralization are discussed.The research results show that:①the strata distributed in the mining area is mainly for Silurian System and Nipen System,among them,Jiangbian Formation and Linong Formation of Silurian are the enriched strata;②the deposit is mainly controlled by strata and tectonic,the whole scale,occurrence and thickness of the deposit vary greatly,the mineralization form is complex and changeable along the tending direction,which occurred as layered stratiform-like and lenticular;③the deposit is mainly controlled by the SN trend faults,NE trend faults and interlayer fracture zone,and the mineralization is enriched in the intersection part of structure;④the mineralization of deposit can be divided into hydrothermal sedimentation,magmatic hydrothermal and tectonic hydrothermal transformation,therefore,the genesis of the copper deposit is defined as hydrothermal sedimentary-hydrothermal reformed deposit.According to the above discussion results,it is further indicated that the west side of Linong ore-section,east side of Lunong ore-section and the combining site have favorable prospecting potential.