投稿时间：2019-05-30
修订日期：2020-05-06
网络发布日期：2020-10-31
中文摘要:铜厂沟斑岩型钼铜矿床位于云南中甸地区斑岩成矿带的南端，形成于燕山晚期陆-陆碰撞至造山后伸展构造的转换阶段。文章通过对铜厂沟钼铜矿床蚀变分带特征和脉体穿切关系的详细研究，系统厘定了矿床蚀变类型及空间分布规律，查明了蚀变和脉体系统与矿化的关系。根据矿物组合、蚀变类型等因素，将分为A脉、B脉和D脉3大类，共16种不同的脉体类型。其中，A脉和B脉与成矿关系密切，对钼铜资源量贡献最大。早期的A脉，主要以钾长石化为主，矿化较弱；晚期形成的A脉多发育有黑云母化且与钾长石化蚀变叠加，矿化增强，以石英+黄铁矿+辉钼矿+黄铜矿±钾长石脉为主；B脉主要贡献于辉钼矿矿体的形成，是区内矿化的主要表现形式，且叠加于钾硅酸盐化，形成于钾硅酸盐化向石英-绢云母化的转变阶段；D脉中铜钼矿化明显减弱，属于矿化体外围的脉体，对矿体影响较小。因此，铜厂沟钼铜矿床蚀变分带规律在空间上表现为钾硅酸盐化（石英-钾长石-黑云母化）发育于斑岩体核部，向外依次是石英-绢云母化（石英-绢云母±黄铁矿化），和青磐岩化（绿泥石-绿帘石-碳酸盐岩化），对应的矿化组合分别为辉钼矿-白钨矿-黄铁矿、辉钼矿-黄铜矿-黄铁矿±白钨矿，以及外带的黄铜矿-黄铁矿-辉钼矿，显示出成矿元素由高温向低温变化的规律。铜厂沟斑岩型钼铜矿床的形成与区内燕山晚期伸展作用相伴的大规模构造-岩浆事件相关，源自深部的含矿热液在花岗质斑岩体内形成了脉状、网脉状的辉钼矿化，同时沿断裂带运移并扩散，于碳酸盐岩的接触带部位形成了矽卡岩型的铜钼矿化。因此，有利的构造环境、强烈的蚀变作用、多样的脉体类型导致铜厂沟大型斑岩型钼铜矿床最终形成。
Abstract:The Tong changgou Cu-Mo copper deposit is located in the south of the porphyry metallogenic belt in Zhongdian area of Yunnan Province. It was formed in the Late Yanshanian continental collision to post orogenic extensional stage. Based on a detailed study of the alteration zoning characteristics and the relationship between vein cutting, the alteration type and spatial distribution of the Tongchanggou Cu-Mo copper deposit were syste-matically determined, and the relationship between alteration and vein system and mineralization was found. According to the mineral assemblage, alteration type and other factors in vein body, it can be divided into three types: A vein, B vein and D vein, with totally 16 different vein body types. Among them, A vein and B vein were closely related to mineralization and contributed the most Mo-Cu resources. In the early A vein, it is mainly K-feldspar with weak mineralization; in the late A vein, biotitization is developed and overlapped with K-feldspar alteration with enhanced mineralization, mainly quartz+pyrite+molybdenite+chalcopyrite±K-feldspar vein. B vein mainly contributed to the formation of molybdenite orebody, is the main form of mineralization in the area, and there is a superposition of potassium silicate salinization, formed at the transition stage from potassium silicate salinization to quartz sericitization. The mineralization of copper and molybdenum in D vein is obviously weakened, which belongs to vein body around the mineralized body and has little influence on the orebody. Therefore, the alteration zoning of the Tongchanggou Mo-Cu copper deposit is characterized by potassium silicate salinization (quartz potash feldspar biotitization) developed in the core of porphyry body, followed by quartz sericitization (quartz sericite ±pyritization) and cyanidization (chlorite epidote carbonatization). The corresponding mineralization combinations are molybdenite scheelite pyrite and molybdenite, with respectively-chalcopyrite -pyrite ±scheelite as well as chalcopyrite-pyrite-molybdenite in the outer belt, showing the regularity of ore-forming elements changing from high temperature to low temperature. The formation of the Tongchanggou Mo-Cu deposit was related to the large-scale tectonic magmatic events associated with the Late Yanshanian extension in this area. The ore-bearing hydrothermal fluid from the depth formed veinlike and network veinlike molybdenization in the granitic porphyry; meanwhile, it migrated and spread along the fault zone, and formed skarn type molybdenization in the contact zone of carbonate rocks. Therefore, the Tongchanggou large porphyry molybdenum copper deposit was finally formed with favorable tectonic environment, strong alteration and various vein types.
keywords:geology Cu-Mo copper deposit granodiorite porphyry mineralization alteration zoning vein system Tongchanggou northwest Yunnan
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基金项目:本文得到国家自然科学基金项目（编号：41862009、41502076）、云南省基础研究计划项目（编号：2019FB062、2019FA018）、云南省科学技术奖-杰出贡献奖项目（编号：2017001）、云南省万人计划“青年拔尖人才”专项（编号：20190028）和昆明理工大学地质资源与地质工程省级一流学科建设项目（编号：1407839305）联合资助
引用文本：
刘学龙,李文昌,张娜,卢映祥,梅社华,朱俊,杨富成,李振焕,罗应,陈建航,王帅帅.2020.滇西北中甸地区铜厂沟斑岩钼铜矿床热液蚀变分带、脉体系统及找矿标志[J].矿床地质,39(5):845~866LIU XueLong,LI WenChang,ZHANG Na,LU YingXiang,MEI SheHua,ZHU Jun,YANG FuCheng,LI ZhengHuan,LUO Ying,CHEN JianHang,WANG ShuaiShuai.2020.Tongchanggou porphyry Mo-Cu deposit in Zhongdian area of northwestern Yunnan：Hydrothermal alteration zone, vein system and prospecting indicator[J].Mineral Deposits39(5):845~866
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