福建省铁帽山钼矿床地质、地球化学异常特征与找矿方向研究  

Geological and Geochemical Anomaly Characteristics and Exploration Targets of the Tiemaoshan Molybdenum Deposit in Fujian Province

作　　者：刘鹤[1,2] 姚敬金 任宏 刘碧洪 

机构地区：[1]中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京100083 [2]中铁资源集团有限公司,北京100039

出　　处：《地球学报》2014年第6期683-692,共10页Acta Geoscientica Sinica

基　　金：国家科技支撑计划课题(编号:2011BAB04B09);教育部新世纪优秀人才支持计划(编号:NCET-09-0710);北京市优秀博士学位论文指导老师科研项目(编号:20111141501);教育部长江学者和创新团队发展计划项目(编号:IRT0755)联合资助

摘　　要：福建铁帽山钼矿床位于闽西南拗陷带,是一个与晚侏罗世中酸性侵入岩有关的斑岩型钼矿床。矿体产出于花岗杂岩体中,杂岩体由中粗粒二长花岗岩、中粗粒钾长花岗岩、花岗斑岩和少量石英闪长岩组成,钼矿体围绕着矿区中部的花岗斑岩岩株近似呈环状分布,主要赋存于蚀变的二长花岗岩中。矿体受到后期断裂构造的破坏而被截断。矿区的围岩蚀变作用强烈,并具有明显的分带特征,自下而上、由内到外可划分为钾化带、石英-伊利石化带、蒙脱石化带和高岭石化带。其中,石英-伊利石化作用与钼矿化作用的关系最为密切。土壤地球化学测量结果显示,Mo元素对数值的频率统计呈双峰式分布,异常下限为12.2×10–6,由此圈定的Mo元素异常近似呈环状分布,与矿体分布范围总体上相一致;而低温成矿元素Zn、Ag元素和高温成矿元素Sn的异常多数分布于Mo元素环状异常的外围和中心低值区。在勘查工作中,石英-伊利石化蚀变和Mo元素地球化学异常可以作为最重要的找矿标志,同时要特别注意断层对矿体的截断和破坏作用。Located in the southwest Fujian geotectogene, the Tiemaoshan molybdenum deposit is a porphyry molybdenum deposit related to Late-Jurassic intrusive bodies. Ore bodies occur within granitic complex which is composed of adamellite, syenogranite, granitic porphyry and minor quartz diorite. Molybdenum ore bodies, dominantly hosted by altered adamellite, are distributed surrounding the granitic porphyry stock at the center of the ore district. Ore bodies are crosscut by the post-metallogenic faults. The intense wall rock alteration shows distinct zoning composed of potassic alteration, quartz-illitization, smectitization and kaolinitization. The quartz-illitization has the most intimate relationship with Mo mineralization. Soil geochemical survey has revealed that the lg Mo has a bimodal frequency distribution. The threshold of Mo could be defined as 12.2×10^-6. The principal Mo anomaly shows ring-like distribution, which is spatially coincident with the ore bodies. However, the anomalies of low-medium temperature elements Zn and Ag as well as the high temperature Sn mostly appear outside and inside the ring-like Mo anomaly. Thus, the quartz-illitization and Mo geochemical anomaly could be considered as the most important targets for exploration. Meanwhile, the destruction and crosscutting actions of faults on ore bodies also deserve special attention.

关 键 词：斑岩型钼矿 围岩蚀变 断裂构造 地球化学异常 找矿方向 

分 类 号：P618.65[天文地球—矿床学] P632[天文地球—地质学]