福建紫金山外围东留花岗斑岩体地质特征及成矿作用分析

Geological characteristics and mineralization of the Dongliu granite porphyry bodies in the periphery of Zijinshan,Fujian Province

福建紫金山及其外围地区分布的浅成-超浅成斑岩体与成矿关切密切。紫金山外围东留花岗斑岩体位于福建省武平县境内,花岗斑岩体内外接触带普遍发育强烈的矿化蚀变带。通过对东留花岗斑岩体进行野外地质调查及全岩地球化学分析,结果表明东留花岗斑岩体具有过铝质A型花岗岩的特征:富硅、钾、铁,贫钙、钠、镁,A/CNK值大于1.1,分异指数高,富集HFSE、Ga、LREE、Y(Ce),亏损Ba、Sr、P、Ti,具有强烈的铕负异常。东留花岗斑岩体作为矿化蚀变岩石的母岩,可能为矿化作用提供热源和成矿物质,具有寻找锡多金属矿的前景。

Hypabyssal-ultrahypabyssal porphyry bodies closely related with mineralization are widely distributed in Zijinshan and its peripheral areas. Dongliu granite porphyry bodies are located in the periphery of Ziiins- ban, Wuping county, Fujian Province. In the endocontact and exocontact zones Of the granite porphyry Bodies, the strong mineralization-alternation zones are widely developed. Based on the field geological sur- vey and bulk geochemical analysis for the Dongliu granite porphyry bodies, it is indicated that the Dongliu granite porphyry bodies have the characteristics of peraluminous A-type granite, being rich in silicon, po- tassium and iron, poor in calcium, sodium and magnesium, with A/CNK ;1.1, with high differentiation indices, and enrichment of HFSE, Ga, LREE, Y（Ce） and poor in Ba,Sr, P,Ti, and strongly Eu anoma- ly. It is considered that the Dongliu granite porphyry bodies, as the parent rock of the mineralized altered rocks, may provide heat sources and ore-forming materials for mineralization, having good prospecting po- tential for tin- polymetallic deposits.