南岭中-晚侏罗世含铜铅锌与含钨花岗岩的成因差异:以湘南铜山岭和魏家矿床为例

发布时间：2018-03-14 00:33

本文选题：含铜铅锌花岗岩　切入点：含钨花岗岩　出处：《中国科学:地球科学》2017年07期 　论文类型：期刊论文

【摘要】：南岭地区中-晚侏罗世含铜铅锌与含钨花岗岩的矿物学和地球化学特征截然不同.含铜铅锌花岗岩主要为准铝质含角闪石的花岗闪长岩,具有较高的CaO/(Na_2O+K_2O)比值、LREE/HREE比值和δEu值,较低的Rb/Sr比值,Ba、Sr、P、Ti轻微亏损,分异演化程度较低.含钨花岗岩为高分异演化的过铝质花岗岩,其CaO/(Na_2O+K_2O)比值、LREE/HREE比值和δEu值较低,Rb/Sr比值较高,Ba、Sr、P、Ti强烈亏损.含铜铅锌花岗岩主要形成于155.2~167.0Ma,峰值为160.6Ma,含钨花岗岩主要形成于151.1~161.8Ma,峰值为155.5Ma,两者存在约5Ma的时差.在湘南铜山岭含铜铅锌和魏家含钨花岗岩系统研究基础上,结合南岭地区中-晚侏罗世含铜铅锌与含钨花岗岩的对比,提出了两类含矿花岗岩的成因模式.古太平洋板块俯冲导致软流圈上涌和玄武质岩浆底侵.底侵玄武质岩浆加热促使下地壳镁铁质角闪岩相基底首先发生部分熔融,形成与铜铅锌矿化有关的花岗闪长质岩浆.随着玄武质岩浆底侵,中-上地壳富白云母变质沉积基底发生部分熔融,形成与钨矿化有关的花岗质岩浆.花岗岩源区成分的差异导致花岗岩成矿专属性不同,源区部分熔融的时间先后导致了含铜铅锌与含钨花岗岩之间存在5Ma左右的时差.
[Abstract]:The mineralogical and geochemical characteristics of copper-lead-zinc and tungsten-bearing granites in the Nanling area are very different. The granodiorite of the copper-lead-zinc-bearing granodiorite, which is mainly quasi-aluminous and hornblende, has a high CaO/(Na_2O K _ 2O ratio and a high LREE / hree ratio and 未 EU value. The lower Rb/Sr ratio is slightly depleted and the degree of differentiation evolution is lower. The tungsten-bearing granites are peraluminous granites with high differentiation evolution. Its CaO/(Na_2O K _ 2O ratio, LREE / HREE ratio and 未 EU value are lower and Rb / Sr ratio is higher. The copper-lead-zinc granite is mainly formed at 155.2n 167.0 Ma.The peak value is 160.6 Ma.The tungsten granite is mainly formed at 151.1161.8 Maand the peak value is 155.5Ma. there is a time difference of about 5Ma between them. On the basis of the study of copper-lead-zinc and Weijia-containing tungsten granite systems in Shanling, Combined with the comparison of the Middle-Late Jurassic copper-lead-zinc and tungsten bearing granites in Nanling area, Two genetic models of ore-bearing granites are proposed. The subduction of the paleo-Pacific plate leads to the upwelling of the asthenosphere and the subduction of the Black Tortoise magma, and the subduction of Black Tortoise magma leads to the first partial melting of the basement of the magnesite amphibolite facies in the lower crust. The granodiorite magma associated with copper, lead and zinc mineralization was formed. With the submersion of Black Tortoise magma, the metamorphic basement of mica rich in the middle and upper crust occurred partial melting. The granitic magma related to tungsten mineralization is formed. The difference in composition of the granite source leads to the difference of the metallogenic specificity of the granite, and the partial melting time of the source region leads to the time difference of about 5 Ma between Cu-Pb-Zn and W-bearing granite.
【作者单位】：南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室;Institut
【基金】：国家自然科学基金项目(批准号:41273053) 国家重点基础研究发展计划项目(编号:2012CB416702) 国家留学基金中法“蔡元培”交流合作项目资助
【分类号】：P588.121;P618.2

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