“石碌式”铁氧化物-铜(金)-钴矿床成矿模式初探  

A preliminary discussion on metallogenic model for Shilu-type iron oxide-copper-gold-cobalt ore deposit

作　　者：许德如[1] 王力[1,2] 肖勇[3] 刘朝露[3] 符启基[3] 蔡周荣[1,2] 黄居锐 

机构地区：[1]中国科学院广州地球化学研究所石油天然气与矿产资源研究中心,广东广州510640 [2]中国科学院研究生院,北京100049 [3]海南省地质矿产勘查开发局资源环境调查院,海南海口570260

出　　处：《矿床地质》2008年第6期681-694,共14页Mineral Deposits

基　　金：全国危机矿山接替资源找矿项目(编码:200646092);国家重点基础研究发展计划973项目(编码:2009CB421001);国家自然科学基金项目(编码:40773017)的资助

摘　　要：石碌铁矿是中国著名的以富赤铁矿为主的大型矿集区,除铁矿外,还共生或伴生铜、钴、镍、银、铅、锌等金属矿产和白云岩、石英岩、重晶石、石膏、硫等非金属矿产。文章通过对石碌铁矿的成矿地质条件和控矿因素的再认识,结合成矿时代的探讨和矿床地球化学资料,认为该矿床严格受层位(主要为青白口纪石碌群第6层)、岩性(钙镁质矽卡岩等)、构造(复式向斜、层间滑脱带、片理和劈理)和/或岩性界面等控制;并强调石碌铁矿所经历的成岩成矿作用与海西期-印支期花岗岩侵位所导致的伸展构造(变质核杂岩构造?)密切相关,而岩浆热扰动则是导致深部含矿热卤水形成、上升并渗滤、交代矿源层的重要因素。最后,作者将该矿床称之为"石碌式"热液铁氧化物-铜-(金)-钴矿床,初步将其归属为IOCG(即热液铁氧化物-铜-金-钴)型层控式钙镁质矽卡岩矿床,并初步构建了该类型矿床的成岩成矿模式。The Shilu iron ore deposit in Hainan Island is one of the famous mining areas in China not only for large amounts of hematite resources but also for considerable economic values of associated metals such as copper, cobalt, nickel, silver, lead and zinc as well as of nonmetallic resources like dolomite, quartzite, barite, gypsum and sulfur. The authors re-studied geological conditions responsible for the formation of the Shilu ore deposit and re-evaluated the major factors controlling the orientations of iron, copper and cobalt ore bodies. The results obtained and the evidence of ore-forming age and geochemical data show that the Shilu ore deposit is strictly controlled by strata （mainly the upper 6th formation of the Meso-Neoproterozoic Shilu Group）, lithologies （chiefly the magnesian skarn）, structures （syncline, interlayer-surging belt, schist and cleavage） and/or interfaees between different lithologies. Diagenesis and metallogenesis in the studied deposit are closely associated with the extension structure, i.e., the metamorphic core complex, which was induced by the emplacement of Hercynian-Indosinian granites. However, magmatic energy after the late Paleozoic not only led to the formation of the orebearing hydrothermal brine at depth but also resulted in the upward migration of the ore-bearing hydrothermal water along various structural pathways and/or interfaces between lithologies. During this process, the ore-bearing hydrothermal brine might infiltrate into and interact with host rocks. As a result, the iron, cobalt and copper-polymetallic ore deposit was formed. Based on the above understanding, the authors have named it for the first time Shilu-type iron oxide-copper-gold-cobalt deposit, and assigned the studied delx）sit to IOCG-type, i.e., iron oxide-copper-gold-cobalt-type strata-bound skarn deposit. A metallogenic model for the studied deposit is also put forward in this paper.

关 键 词：地质学 成矿地质条件 控矿因素 成岩成矿模式 “石碌式”热液铁氧化物-铜(金)-钴矿床 海南省 

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