青海治多县多彩铜铅锌矿床蚀变矿化分带性与成因类型  

Alteration-Mineralization Zoning and Genetic Type of the Duocai Cu-Pb-Zn Deposit in the Zhiduo Area,Qinghai Province

作　　者：徐佳富 李青云[2] 谭俊[1] 魏俊浩[1] 赵少卿[3] 詹小飞 张飞[1] 刘颜[1] 甘觐荣 

机构地区：[1]中国地质大学资源学院,武汉430074 [2]中国黄金集团公司,北京100871 [3]长江大学地球科学学院,武汉430100

出　　处：《地质科技情报》2016年第6期167-176,共10页Geological Science and Technology Information

基　　金：中国地质调查局项目"青海省多彩地区铜多金属矿整装勘查区关键基础地质研究"(科[2014]04-025-081)

摘　　要：多彩铜铅锌矿床位于"三江"多金属成矿带北段青海省南部的治多县,是目前该地区新发现的唯一一个与古特提斯火山作用有关的大型矿床。矿体产于晚三叠世巴塘群火山岩地层中,直接赋矿围岩为英安质凝灰岩。矿区内主要发育硅化、绢云母化、黄铁矿化、绿泥石化、重晶石化、白云石化、方解石化等蚀变,矿化类型以块状及浸染状铜铅锌矿化和纹层状及星点状铜矿化为主,其次为细脉状铜铅锌矿化等。蚀变矿化在空间上具有明显分带性,以白云石-重晶石固结壳为界,下盘依次出现硅化-重晶石化-块状及细脉状矿化带、硅化-黄铁矿化-稠密浸染状矿化带、黄铁矿化-硅化-绢云母化-稀疏浸染状矿化带、硅化-弱绿泥石化带、绿泥石化带。上盘则多为成矿后中低温蚀变组合,如弱硅化-弱绢云母化-绿泥石化等。成矿演化上,矿床经历了3期主要成矿作用:火山沉积-气液矿化期、海底喷流热液矿化期及表生期。矿床地质特征、蚀变矿化分带及成矿演化等的综合分析表明,多彩铜铅锌矿床与日本黑矿及同一构造带的"三江"中段川西呷村VMS矿床极为相似,属于火山岩容矿的块状硫化物矿床。Duocai, the only large-scale Cu-Pb-Zn deposit related to the Paleo-Tethys volcanism in the south of Qinghai section up to now, is located in the northern segment of Sanjiang Metallogenic Domian. The ore body is mainly in the Batang Group volcanic stratum of late Triassic, and dacitic tuff is the direct host rocks of Cu-Pb-Zn orebody. The Duocai Cu-Pb-Zn deposit is characterized by a variety of alternation types, including silicifieation, serieitization, pyritization, chloritization, baratization, dolomitization and calcitization. The mineralization consists of massive and disseminated Cu-Pb-Zn mineralization, lamellar and starshaped Cu mineralization, and small veined Cu-Pb-Zn mineralization. It is worth noting that the alteration and mineralization of Duocai Cu-Pb-Zn deposit generally present mineral zonation in space. From the solid crust consisting of dolomite and barite to the footwall-rock, the alteration and mineralization zonation, in turn, displays silicide-barite-massive and small veined zone, silicide-pyrite-dense disseminated mineralized zone,pyrite-sericite-silicite-sparse disseminated mineralized zone, silicite-weak chlorite zone and chlorite zone. The alternation types of hanging wall are medium low temperature alternation after mineralization, such as weak silicification-weak sericitization-chloritization. On the other hand, the Duocai Cu-Pb-Zn deposit may have experienced three major ore-forming processes. They are volcanogenic sediment-gas liquid period, submarines pouting hydrothermal period and supergene period. Combined with the geology, alteration-mineralization zoning and metallogenic evolution processes, we suggest that the Duocai Cu-Pb-Zn deposit has similar original mechanism and ore genesis with the Kuroko type deposit in Japan and the G-acun VMS deposit which located in the middle segment of Sanjiang Giant Metallogenic Domian, and the genetic type of the deposit is volcanic-hosted massive sulfide deposit.

关 键 词：蚀变 矿化 分带性 多彩铜铅锌矿床 “三江”北段 青海 

分 类 号：P618.2[天文地球—矿床学]