安徽月山岩体地球化学特征及成因机理分析

摘要

Yueshan ore field is a typical skarn-hydrothermal t ype of Cu (Fe),Au polymetallic ore field in the mineralisation belt of the Midd le and Lower reaches of the Yangtze River area.Copper-gold deposits in this ore field have close relations h ip with the Yueshan intrusion.The intrusion consists of diorites,quartz diorit es and quartz monzonitic diorites.The geological and geochemical characteristic s,especially the petrochemistry,REE,trace elements and Pb,Sr,Nd,O isotope g eochemistry of this intrusion,as well as geochemical modeling of its petrogenet i c process,are discussed.The results show that the Yueshan intrusion is a MC-t yp e granite with 70% of mantle-derived material and 30% of crust-derived materia l.It was formed by the process of combined wall-rock assimilation of the crust al ma terial and fractional crystallization of the mantle-derived alkaline basalt.An open magmatic system of the Yueshan dioritic body is essential to formation and evolution for the ore-forming fluid of the metallic ore deposits in this field.%通过对长江中下游地区具代表性的大型矽卡岩- 热液脉型铜（铁）、金、多金属矿田中成矿岩体—月山岩体的地质地球化学特征及其成因制约与反演讨论，认为该岩体为深源的碱性玄武质岩浆经过结晶分异和同化混染联合作用（AFC过程）形成的，其中，幔源物质约 占70%，同化的壳源物质占30%。这种开放岩浆系统的形成与演化对于该区金属矿床成矿流体 系统的形成与演化具有极其重要的意义。