凤凰山铜矿床两类成矿岩体的厘定及其成因分析

本文从地质、地球化学以及矿化蚀变特征等方面对凤凰山矿田内两类不同成矿岩体的特征进行了对比,指出凤凰山复式岩体由早期的花岗闪长岩和晚期的石英二长闪长斑岩所组成,与花岗闪长岩有关的成矿作用主要为矽卡岩型成矿作用,与石英二长闪长斑岩有关的成矿作用主要为斑岩型成矿作用.并对新发现的斑岩型矿化的大地构造背景、围岩、蚀变特征、控矿构造以及矿石类型进行了阐述.最后,在综合分析成矿物质来源、物理化学条件、成矿流体和成矿作用的基础上,对凤凰山铜矿床的成因进行了探讨,认为矿床的形成主要与中酸性岩浆活动有关,经历了多种成矿作用,形成了多种矿化型式,矿床成因属以岩浆热液为主的复合型热液矿床.

Identification of two types of mineralized intrusion in the Fenghuangshan copper deposit and analysis of their genesis

A comparison is mode between two types of mineralized intrusion in the Fenghuangshan ore field in respect to the geological,geochemical and mineralization and alteration characteristics in the paper.The Fenghuangshan composite intrusions are composed of early-stage granodiorite and late-stage quartz monzodiorite porphyry.Skarn-type mineralization is the main mineralization related to granodiorite and porphyry-type mineralization is mainly related to quartz monzodiorite porphyry.From the tectonic setting, wall rocks,alteration characteristics,ore-controlling structure and ore types,the paper discusses the characteristics of the newly found porphyry-type mineralization.Finally,on the basis of an integrated analysis o the source of ore-forming substances,physical-chemical conditions,ore-forming fluids and mineralization,the genesis of the deposit is discussed.The authors think that the formation of the deposit is mainly related to intermediate-acid magmatism and progressed through several mineralizations,thus forming different mineralization types.The deposit is genetically a compound hydrothermal deposit formed mainly by magmatic hydrothermal processes.