福建漳平洛阳铁矿床成岩成矿年代学及其地质意义  

Geochronology of Diagenesis and Mineralization of the Luoyang Iron Deposit in Zhangping City,Fujian Province and Its Geological Significance

作　　者：张达[1,2] 吴淦国[1,2] 狄永军[1] 王长明[1] 姚继明[1] 张垚垚[1] 吕良冀[1] 袁远[1] 石建基[3] 

机构地区：[1]中国地质大学地质过程与矿产资源国家重点实验室,北京100083 [2]中国地质大学岩石圈构造、深部过程及探测技术教育部重点实验室,北京100083 [3]福建省地质矿产勘查开发局,福建福州350003

出　　处：《地球科学（中国地质大学学报）》2012年第6期1217-1231,共15页Earth Science-Journal of China University of Geosciences

基　　金：地质调查项目(Nos.1212011085472,1212010533105,1212010813064);“111”计划(No.B07011)

摘　　要：为了确定闽西南地区铁矿床成矿时代及主要成矿作用特征,选取洛阳铁矿床开展花岗岩LA-ICP-MS锆石U-Pb同位素测龄及辉钼矿Re-Os同位素年代学研究.结果表明洛阳铁矿床中辉钼矿Re-Os同位素模式年龄为(133.0±1.9)～(134.0±4.2)Ma,为早白垩世成矿.矿区花岗斑岩结晶年龄为131±1Ma,细粒斑状花岗岩结晶年龄为131.64±0.62Ma,说明岩体都形成于早白垩世.通过对洛阳铁矿床花岗岩、磁铁矿体及辉钼矿体空间分布规律及矿化蚀变特征综合分析,结合岩体与矿床年代学结果,可以得出洛阳铁矿床主要形成于早白垩世,与早白垩世花岗岩岩浆热液接触交代石炭纪碎屑岩-碳酸盐岩地层密切相关.In order to determine the main mineralization time and ore forming genesis in the southwestern Fujian Province,this paper selects the Luoyang iron deposit to develop the study of LA-ICP-MS zircon U-Pb isotopic dating for granite and Re-Os geochronology for molybdenite from the iron ore body.According to the results,the molybdenite Re-Os isotopic model date is（133.0±1.9）to（134.0±4.2）Ma,which belongs to Early Cretaceous;and LA-ICP-MS zircon U-Pb isotopic dates for the granite porphyry and fine grain porphyritic granite are（131±1）Ma and（131.64±0.62）Ma respectively,which is very close to the mineralization time achieved by the Re-Os isotopic dating.According to the analysis of the granites,spatial distribution of magnetite and molybdenite ore bodies,and the mineralization and alteration characteristics,combining with the above granite and deposit chronological data,it is suggested that the Luoyang iron deposit mainly formed at Early Cretaceous when the contact thermofluid metasomatism occurred between the Early Cretaceous granites and the Carboniferous clastic and carbonate strata.

关 键 词：RE-OS同位素年龄 LA-ICP-MS锆石U-Pb年代学 辉钼矿 洛阳铁矿 岩石学 成矿预测 矿床 

分 类 号：P611.1[天文地球—矿床学]