滇西北羊拉铜矿床断裂构造、构造控矿模式及找矿预测

Fault structure,ore- controlling structural model and prospecting prediction of Yangla copper deposit,northwestern Yunnan

羊拉铜矿是金沙江成矿带内规模最大的铜矿床。文章在总结矿床地质特征的基础上,系统开展了断裂构造及构造控矿模式的研究,并进行找矿预测。研究表明:羊拉铜矿区存在近南北向构造带、北东向构造带和北西向构造带等3种断裂构造体系,反映矿区构造经历了4期构造运动,分别对应晚海西期、印支期、燕山期和喜山期;总结羊拉铜矿区构造控矿模式为印支期"岩浆侵入接触构造+层间断裂"和燕山—喜山期"入字型构造+阶梯状构造"。同时依据成矿模式和地质事实,指出江边矿段西侧夕卡岩型矿体、路农矿段东侧深部夕卡岩矿体和里农西侧深部斑岩型铜矿是今后重要的找矿方向,并提出了相应的勘探设计。

The Yangla large copper deposit located in Deqin county,northwestern Yunnan,is the largest scale copper deposit in the Jinshajiang metallogenic belt. Based on summarization of geological characteristics of the Yangla copper deposit,this paper studies the fault structure and ore- controlling structural model,then the prospecting prediction is carried out. The tectonic analysis results show that the tectonic system within Yangla copper deposit can be divided into three groups of systems,i. e.,near SN- trending tectonic belt,NE- trending tectonic belt and NW- trending tectonic belt,which indicate that the Yangla copper deposit has experienced four stages of tectonic movements which are correspondent to late Hercynian,Indo- Sinian epoch,Yanshanian and Himalayan movement respectively. The study has summarized Two types of ore- controlling structural models,i. e.,＂contact structure between magmatic intrusive and country rock and interlayer fault＂model of Indo- Sinian epoch and＂λ type structure style and latter- type structure＂of Yanshanian and Himalayan epoches. Meanwhile,according to the metallogenic model and geological facts,three important prospecting targeting areas were proposed for the further exploration,i. e.,skarn- type copper orebodies in the western part of the Jiangbian oresection,skarn- type copper orebodies in the depth of eastern Lunong oresection,and porphyrytype copper orebodies in the depth of western Linong oresection. The corresponding exploration plan and design have also been put forward in this paper.