赣南印支期白石钨(铜)矿床成矿岩体地球化学特征及地质意义  

Geochemical Characteristics and Geological Significance of the Ore-forming Granite of Indosinian Baishi W-Cu Deposit in Southern Jiangxi Province

作　　者：李利 王国光[2] 李海立[3,4] 肖惠良[3] 陈乐柱 LI Li;WANG Guoguang;LI Haili;XIAO Huiliang;CHEN Lezhu(Jiangsu Urban and Rural Construction Vocational College,Changzhou 213147,Jiangsu,China;State Key Laboratory for Mineral Deposits Research,Nanjing University,Nanjing 210023,Jiangsu,China;Nanjing Geological Survey Center,China Geological Survey,Nanjing 210016,Jiangsu,China;University of Science and Technology of China,Hefei 230026,Anhui,China)

机构地区：[1]江苏城乡建设职业学院,江苏常州213147 [2]南京大学内生金属矿床成矿机制研究国家重点实验室,江苏南京210023 [3]中国地质调查局南京地质调查中心,江苏南京210016 [4]中国科学技术大学,安徽合肥230026

出　　处：《黄金科学技术》2023年第5期736-751,共16页Gold Science and Technology

基　　金：江苏城乡建设职业学院校级科研项目“矿物自动识别技术在地质领域的应用研究——以TIMA为例”(编号:XJZK21013);南京大学内生金属矿床成矿机制研究重点实验室开放基金项目“江西德兴超大型斑岩型铜(钼金)矿田成矿流体和成矿机制研究”(编号:2022-LAMD-K09);江苏省高等学校基础科学(自然科学)研究面上项目“江苏东海毛北金红石矿流体成矿过程和成矿机制研究”(编号:22KJD170001);江苏省发改委项目“江苏省低碳建材与城乡生态工程研究中心”(编号:苏发改高技发[2021]1368号);中国地质调查局地质调查项目“江西遂川—石城地区锂铍铌钽等矿产地质调查”(编号:DD20230277)联合资助。

摘　　要：白石钨(铜)矿床是赣南印支期的一个中型石英脉型矿床,其成矿岩体的研究薄弱。为探究成矿岩体的岩浆成因及其与成矿之间的关系,以白石花岗岩为对象,开展了地球化学研究。白石花岗岩具有富硅、总碱含量高、铝饱和指数高及分异指数较高的特征,在稀土元素配分曲线上显示右倾的特征,Eu异常明显,微量元素蛛网图上显示富集大离子亲石元素(如Rb、Th和U),亏损高场强元素(如Nb和Ti)。上述岩石地球化学特征及相关地球化学图解均表明白石花岗岩为分异的S型花岗岩。研究结果揭示,白石花岗岩为板内环境形成的花岗岩,源岩为泥质岩,形成过程以分离结晶作用为主,形成于印支造山运动后的伸展环境,与华南印支期的成矿作用密切相关。The Baishi W-Cu deposit is a medium-sized quartz vein type deposit formed in Indosinian in southern Jiangxi Province.It belongs to the Nanling metallogenic belt.Although it had been exploited since the founding of the People’s Republic of China,few studies have been done on ore-forming mass.The Baishi granite is the main magmatic rock exposed in the mining area and it is recognized as the ore-forming rock.The Baishi granite has undergone carbonation,chlorite,and muscovite alteration.The Baishi granite has obvious tungsten and copper mineralization.In order to probe into the magma genesis and its relationship with metallogenesis,this study conducted detailed geochemical analysis for the Baishi granite.From the feature of the major elements,the Baishi granite has relatively high SiO2 contents(71.59%~75.36%),total alkali content(Na2O+K2O:6.28%~7.45%),aluminum saturation index(A/CNK:1.71~2.11)and differentiation index(DI:81.53~90.39).It can be inferred that the Baishi granite is peraluminous granite and it has a high degree of differentiation.In the characteristics of rare earth elements,the Baishi granite exhibits obvious enrichment of light rare earth elements,relative depletion of heavy rare earth elements(LREE/HREE=9.94~12.29)and obvious Eu negative anomaly(δEu=0.28~0.57).Additionally,in the diagram of trace element spider pattern,the Baishi granite is relatively enriched in large ion lithophile elements,such as Rb,Th and U,and depleted in high field strength elements,such as Nb and Ti.While Ba is depleted relative to Rb.The geochemical characteristics mentioned above and relevant geochemical diagrams of the Baishi granite display obvious characteristics of differential S-type granites.Based on the comprehensive analysis,it can be concluded that the Baishi granite is formed in the intraplate environment.The Baishi granite’s magma source is crust and it is mainly derived from the pelite.In addition,the fractional crystallization plays more important role in its forming process than partial melting.In terms of

关 键 词：白石花岗岩 岩石地球化学 S型花岗岩 印支期 成矿作用 赣南 

分 类 号：P518.2[天文地球—地质学]