滇中黄草岭铜矿床地质特征及成因研究

Geological characteristics and genesis of Huangcaoling Copper Deposit,Central Yunnan

滇中黄草岭铜矿地处云南东川铜矿集区之落因成矿带。以黄草岭铜矿的矿床地质特征为主要研究对象,通过仔细观察、分析其矿体特征、矿石结构构造、矿物组分及生成顺序、围岩蚀变等,并通过综合类比研究,对矿床成因进行初步讨论。研究表明,黄草岭铜矿床赋存于落雪组厚层状白云岩中,测试分析结果表明,落雪组围岩的铜含量为0.06%~0.19%,而矿（化）体中铜品位为0.22%~1.69%,可见成矿元素存在从围岩至矿（化）体逐步富集的特征。该矿床成矿作用分为两个阶段：第一阶段在落雪组白云岩沉积成岩过程中成矿元素初步富集形成矿源层;第二阶段为后期在热液流体的萃取、淋滤作用下,成矿物质沿着东西向裂隙进一步富集成矿,其成因可以归属于＂东川式＂沉积变质叠加热液改造矿床。

The Huangcaoling Copper Deposit is located in the Luoying metallogenic belt of copper mineralization area in Dongchuan,Central Yunnan.This paper mainly reports geological features of ore body,texture and structure of copper ores,mineral composition and formation order,alteration of the surrounding rock etc.Based on the above observation and analysis in combination with general comparative study,the genesis of Huangcaoling Copper Deposit has been discussed.Researches show that this copper deposit occurs in thick-bedded dolomite of Luoxue formation.The test results show that the copper content of wall rock of Luoxue formation ranges from 0.06% to0.19%,grades of ore are in the range of 0.22%~1.69%.Obviously,metallogenic elements enrich gradually from the wall rock to ore body.The mineralization can be divided into two stages,at first stage the mineral elements completed preliminary enrichment and formed ore source bed in Luoxue formation dolomite,at second stage the late hydrothermal fluid extracts and leaches material from dolomite,and along the East-West fracture enriches further into mineralization.Therefore,the genesis of Huangcaoling Copper Deposit can be attributed to＂Dongchuan type＂that is sedimentary-metamorphic superimposed by hydrothermal alteration type deposit.