云南东川铜矿马尾丝状铜矿石特征及成因  

Characteristics and Genesis of the Horsetail-like Copper Ore in Dongchuan Copper Deposit,Yunnan

作　　者：曾瑞垠 祝新友 张雄 吕晓强 黄建业 谭康雨 姜华[1,4] 田犁平 ZENG Ruiyin;ZHU Xinyou;ZHANG Xiong;Lü Xiaoqiang;HUANG Jianye;TAN Kangyu;JIANG hua;TIAN LiPing(Faculty of Land Resource Engineering.Kunming University of Science and Technology,Yunnan 650093;Sino-Zijin Resources Ltd.,Beijing 100012;Sinotech Minerals Exploration Co.,Ltd.,Beijing 100012;Yunnan Copper Co.,Ltd.,Kunming 650000;Geological Team 306 of Yunnan Non-ferrous Metals Geological Bureau,Kunming 650217)

机构地区：[1]昆明理工大学国土资源工程学院,昆明650093 [2]中色紫金地质勘查(北京)有限责任公司,北京100012 [3]中色地科矿产勘查股份有限公司,北京100012 [4]云南铜业股份有限公司,昆明650000 [5]云南省有色地质局三〇六队,昆明650217

出　　处：《矿产勘查》2021年第4期972-979,共8页Mineral Exploration

基　　金：中国铜业有限公司重点科技计划项目“云南东川铜矿成矿规律与成矿预测”(编号:2018K01)资助。

摘　　要：东川铜矿位于扬子板块西南缘康滇构造带中,其矿体发育在落雪组白云岩中,典型矿石为马尾丝状铜矿石。本文对马尾丝状铜矿石的宏观和微观特征进行总结,通过ICP-MS和EMPA方法获得铜矿石和白云石主量元素特征,综合收集硫同位素值,对其成因进行探讨。研究表明马尾丝状铜矿石由顺层细矿脉和高角度切层含矿脉组成,两者在结构、构造、矿物组成、Ca/Mg比值等方面基本一致,具有明显的交代结构。容矿岩石表现为砂质层与泥质层互层,顺层细矿脉主要分布于砂质层中,马尾丝状铜矿石的SiO_(2)含量明显高于弱矿化白云岩,说明顺层细矿脉发育于渗透性较好的石英砂质白云岩中。含矿卤水沿断裂构造运移至落雪组白云岩中,向两侧含孔隙度较高的砂质白云岩和叠层石白云岩顺层交代,形成以马尾丝状铜矿石为主的东川式层状铜矿体,马尾丝状铜矿石属于盆地卤水交代成因。Dongchuan copper deposit is located in the Kangdian tectonic belt,southwest margin of the Yangtze plate.Dongchuan type copper body is developed in the dolomite of Luoxue Formation,and its typical ore is horsetail-like copper ore.In this paper,we summarized the macro-and microscopic characteristics of horsetail-like copper ore,evaluating the main element characteristics of copper ore and dolomite by ICP-MS and EMPA methods.Combined with the sulfur isotope values,we discuss the origin of the horsetail-like copper ore.The results show that the horsetail-like copper ore consists of bedding fine veins and high-angle ore-bearing veins,which are basically the same in structure,tectonic,mineral composition and Ca/Mg ratio.The two veins exhibit obvious metasomatic structure.The ore-hosting rocks are interbedded with sandy layer and argillaceous layer,and the bedding fine veins are mainly distributed in the sandy layer.The SiO_(2) content of the horsetail-like copper ore is obviously higher than that of the weak mineralized dolomite,indicating that the bedding fine veins are developed in the quartz sandy dolomite with better permeability.The ore-bearing brine migrated to the dolomite of the Luoxue Formation along the fault structure and metasomatized to the sandy dolomite and stromatolite dolomite with high porosity on both sides,forming the Dongchuan type stratified copper body characterized by horsetail-like copper ore,which belongs to the brine metasomatism genesis of the basin.

关 键 词：顺层细矿脉 高角度含矿脉 砂质层 马尾丝状铜矿石 东川铜矿 

分 类 号：P611[天文地球—矿床学]