滇中易门里士北部水下碳酸质火山-喷流岩铁、铜矿化及其大型隐伏矿床找矿研究  

Zhang YB,Xu CY,Xiao MY,Wang H,Zhao CS,Zhu ZH and Li LJ.2005.Study on Fe,Cu mineralization generated in subaqueous carbonatitic volcano-hydrothermal activity and their large insidious ore deposit prospecting in the northward of Lishi,Yimen,Central

作　　者：张永北[1] 徐成彦[2] 肖明远[2] 王豪[2] 赵重顺 朱智华 李连举 

机构地区：[1]海南省师范大学资源环境与旅游系 [2]中国地质大学地球科学学院,武汉430074 [3]云南省有色金属西南地质勘察局,昆明650051

出　　处：《岩石学报》2005年第5期1395-1408,共14页Acta Petrologica Sinica

基　　金：本文受中国科学院重点项目(KZ951-B1-404)经费支持;中国矿物资源重点实验室帮助.

摘　　要：易门里士北部磁异常区中元古代是一个比周边相对低洼的碱性-碳酸质火山水下活动环境。因民组含矿层除有(次)火山岩和火山辞屑沉积岩外,还有粘土质-绿脱石岩、铁质岩、铁质硅质岩、铁质泥岩、碳酸盐岩、泥质白云岩、硅质白云岩等热液喷流岩含钠质硅酸盐团砾的碳酸质岩及碳酸盐晶屑组成的岩石是碳酸质火山岩。岩石、矿石的高场强元素对比值、稀土元素球粒陨石标准化比值、硫化物 Co/Ni 和 S 同位素比值显示喷流岩源于碱性-碳酸质火山岩,热液交代对成矿作用也有重要贡献,喷流岩除了铁矿化,还有铜、钴、锌、银等。如果将本区矿化岩石与典型喷流矿床——日本黑矿对比,果树村附近的网脉状矿化次火山岩、角砾熔岩、矿化角砾岩类似于喷流中心的矿化英安岩穹和角砾岩;磁异常北缘相同层位的含石膏富BaO 铁质泥岩和铁质硅质岩则相当于低洼地的石膏和重晶石沉积岩。本区磁异常与黑矿主矿一样在喷流岩层内处于喷流口与膏盐沉积洼地之间,其周边的铁矿点绝不是矿化的主体。大型含铜铁矿应该隐伏在深部因民组含矿层个于喷流中心和石膏、重晶石层之间的磁异常体中。The palaeoenvironment of the magnetic anomaly area in the northward Lishi, Yimen was a low depression relative to its surrounding in Proterozoic, when the subaqueous alkaline-carbonatitic volcanoes erupted. The ore-bearing layers of Yinmin Formation are consist of （sub）volcanic rocks, pyroclastic sedimentary rocks and hydrothermal rocks including clayey-nontronite rock, ferruginous rock, ferruginous sillcalite, ferruginous ruffite, carbonate rock, muddy dolomite, sillcacous dolomite et al, The rocks consisted of carbonate mineral fragments or the carbonatic rocks with sodium silicate mass are caibonatitie volcanic rocks. Nb/Ta,Zr/TiO2 ,Nb/Y, Zr/Hf,U/Th ratios of HFSEs, and （La/Nd） n, （Sm/Nd） n, （La/Yb）n ratios of chorndrite-abnormalied REEs of the rocks and ores, and Co/Ni, sulfur isotopic ratios of sulfide reveal that the hydrothermal rocks is derived from alkaline-carbooatitic volcanic rocks, as well as the hydrothermal metasomatism took an important role in the mineralization. The mineralization in the hydrothermal rocks includes iron as well as copper, zinc, cobalt and silver. If compared the mineralization rocks with the typical hydrothermal ore deposit, Kuroko deposits in Japan, the network mineralized subvolcanoic rock, blocky lavas and breccia near by Lishucun are similar to the mineralized dacite dome and breccia in the eruption central. The ferruginous ruffite and ferruginous sillcalite with high BaO and gypsum occurring in same horizontal on the margin of the magnetic anomaly are corresponded to the barite and gypsum sediment in the low depression of Kuroko deposit. The main ore-bodies of Kuroko is just setting on the space between eruption opening and barite and gypsum depression, and northward Lishi magnetic anomaly just appear in this kind space. Apparently, the main body of mineralization in this area is absolutely not the small iron mine on the margin of magnetic anomaly. A large copper-bearing iron ore deposit is most likely lying under the deep of magnetic anomaly space between t

关 键 词：滇中 昆阳群 昆阳裂谷带 碳酸岩 火山热液喷流岩 铁铜矿床 成矿预测 

分 类 号：P618.31[天文地球—矿床学] P618.41[天文地球—地质学]