铜陵矿集区中生代侵入岩成因及成矿意义  

Petrogenesis of the Mesozoic Intrusive Rocks From the Tongling Ore Cluster Region:The Metallogenic Significance

作　　者：谢建成[1,2] 杨晓勇[1] 肖益林[1] 杜建国[3] 孙卫东[1,4] 

机构地区：[1]中国科学技术大学地球和空间科学学院矿产资源研究室,合肥230026 [2]合肥工业大学资源与环境工程学院,合肥230009 [3]安徽省地质调查研究院,合肥230011 [4]中国科学院广州地球化学研究所,广州510640

出　　处：《地质学报》2012年第3期423-459,共37页Acta Geologica Sinica

基　　金：中国科学院知识创新工程重大项目(编号KZCX1-YW-15-3);国家自然科学基金项目(编号41173057);高等学校博士学科点专项科研新教师类基金(编号20100111120012);合肥工业大学博士专项基金(编号GDBJ2008-041);安徽国土资源厅项目"铜陵地区找矿专题"共同资助的成果

摘　　要：安徽铜陵矿集区是我国最著名的铜、金、铁产地之一,成矿与岩浆作用关系密切。本次对铜陵地区中生代侵入岩进行了系统的矿物学、岩石学和元素地球化学研究。结果表明:①本区岩浆岩主要为辉石(二长)闪长岩(SiO2≤55%)、石英(二长)闪长岩(SiO255%～65%)和花岗闪长岩(SiO2≥65%)三种岩石组合,其矿物成分主要为中长石、正长石、镁质黑云母和直闪石-铝直闪石系列。②辉石(二长)闪长岩组合岩石主要为碱性和橄榄玄粗岩系列。带有古老俯冲洋壳成分的富集岩石圈地幔分离结晶作用可能是辉石(二长)闪长岩组合岩石产生的最主要原因。③花岗闪长岩、石英(二长)闪长岩组合岩石主要属于亚碱性和高钾钙碱性系列,其某些地球化学特征和埃达克岩的地球化学特征一致。幔源岩浆和壳源岩浆的混合可能是石英闪长岩组合和花岗闪长岩组合岩石的主要形成机制。④早白垩世岩浆活动及其相关的铜、金成矿作用可能与古太平洋板块俯冲及其演化过程密切相关。Tongling ore cluster region is one of the most important non-ferrous metal producers where the formation of Cu-Au deposits has close genetic relation to Mesozoic intrusions.Petrology,mineralogy and element geochemistry of these Mesozoic intrusive rocks in the Tongling region were investigated.These results show：①The intrusive rocks can be divided into three rock associations：pyroxene diorite with SiO2≤55%,quartz diorite with SiO2 55%~65%,and granodiorite associations with SiO2≥65%.Their mineral components are mainly with characteristics of andesine,orthoclase,Mg-biotite,and anthophyllite-aluminium anthophyllite series.②Pyroxene diorite association rocks are mainly with characteristics of shoshonite.They were most probably produced by fractional crystallization primarily derived from an enriched mantle which has the material contribution of ancient subducted ocean crust,and experienced assimilation of a little lower crustal material.③Quartz diorite and granodiorite association rocks are mainly composed of high potassic calc-alkaline.They were possibly resulted from the crustal assimilation and fractional crystallization（AFC）.The mixing of mantle-derived and crust-derived magmas might have been the main mechanism throught which quartz diorite and granodiorite associaltion rocks were produced.4）The early Cretaceous period magmatic activity and related metallogenesis are closely related to the Pacific plate subduction.

关 键 词：岩石组合 岩浆混合 太平洋板块俯冲 分离结晶 同化混染 铜陵矿集区 

分 类 号：P612[天文地球—矿床学]