【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.更多还原

【Abstract】 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.更多还原