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安徽东至县赵家岭金矿床岩浆岩石学特征及意义
摘要
赵家岭金矿床是近年来在安徽省东至县发现的具一定规模的金矿床,包括多个矿段(点),其矿床的形成与燕山期岩浆活动有密切的成因联系。本文通过对区内岩浆岩岩石学特征研究,确定了区内主要岩浆岩成因类型为I型(壳幔同熔型)花岗岩,属高钾钙碱性和钙碱性岩浆岩系列;稀土元素总体表现为LREE富集,HREE亏损特征,与长江中下游地区岩浆岩类似;岩石化学特征表现出具埃达克质岩石性质;通过岩石学及地球化学特征,并结合矿床勘查认识分析,认为区内燕山早期花岗闪长斑岩和花岗斑岩为埃达克质岩石,其发育于陆内碰撞造山带构造应力由挤压转变为伸展的转折期,受中国东部燕山期岩浆-成矿作用统一的构造环境制约。
The Zhaojialing gold ore deposit is of considerable size of its kind found in Dongzhi County,Anhui Province in recent years.It includes many ore blocks(prospects) and is formed genetically and closely related to the Yanshanian magmatic activities.By studying petrological features of magmatic rocks in the area this paper found they are mainly of I type granite(crust-mantle syntectic type),a part of high-K calc-alkaline and calcalkaline series,with LREE enrichment and HREE loss,similar to magmatic rocks in the mid-lower Yangtze River reaches,Petrochemically they have the features of Adakites.Petrology,geochemistry and ore deposit understanding all point to that the early Yanshanian granodiorite porphyry and granite porphyry are Adalites,which are developed in the turning period from compression to extension of structural stress of intracontinental collision orogen,and confined by the unified structural environment of the Yanshanian magmatism and metallogenesis in eastern China.
引文
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