南岭东段北部花岗岩的萤石成矿专属性研究  

Metallogenetic Specialization of the Fluorite-bearing Granites in the Northern Part of the Eastern Nanling Region

作　　者：方贵聪[1,2] 王登红[3] 陈振宇[3] 陈郑辉[3] 赵正[3] 郭娜欣[2] 

机构地区：[1]桂林理工大学地球科学学院,广西桂林541004 [2]中国地质科学院,北京100037 [3]国土资源部成矿作用与资源评价重点实验室中国地质科学院矿产资源研究所,北京100037

出　　处：《大地构造与成矿学》2014年第2期312-324,共13页Geotectonica et Metallogenia

基　　金：国家深部探测技术与实验研究专项“南岭成矿带地壳岩浆系统结构探测实验”(编号:SinoProbe-03-01);中国地质大调查项目“南岭地区岩浆岩成矿专属性研究”(编号:1212011120989)、中国地质大调查项目“广东诸广山南部整装勘查区铀多金属矿成矿地质条件与综合找矿方法研究”(编号:12120113090500)资助;国土资源部成矿作用与资源评价重点实验室开放研究项目“南岭科学钻(SP-NLSD-2)花岗岩-云英岩化带-钨矿石英脉:地球化学特征及岩浆-流体演化”、“我国重要矿产和区域成矿规律研究”课题(编号:1212010633903)、“南岭于都-赣县矿集区立体探测技术与深部成矿预测示范”课题(编号:201011048)

摘　　要：为了探讨花岗岩的萤石成矿专属性特征,在系统搜集前人成果基础上,对南岭东段北部产萤石花岗岩和非产萤石花岗岩开展了元素地球化学测试和黑云母电子探针分析(EPMA)与对比。结果表明:产萤石花岗岩主要为黑云母花岗岩,属于高钾钙碱性系列,副矿物组合中常见萤石;加里东期、印支期和燕山期的花岗岩均具有形成萤石矿床的可能性,以燕山早期花岗岩的潜力最大。与非产萤石花岗岩相比,产萤石花岗岩具较高的Mo含量和较低的Th/U比值;其黑云母主要为铁质黑云母和铁叶云母,比非产萤石花岗岩的黑云母(主要为铁白云母和铁叶云母)更富TiO2、MgO、Cl、F而贫Al2O3、FeO+Fe2O3;黑云母的F与Cl含量呈正相关,而与Al2O3含量呈负相关;产萤石花岗岩形成于相对高温、低压和高氧逸度的环境,岩浆来源主要为地壳,但有少量幔源,与钨多金属矿床关系较为密切。Fluorite deposits in the northern part of the eastern Nanling region are intimately associated with granitic intrusions. To investigate their fluorite-metallogenetic specialization, the chemical compositions of biotites and whole rock of the granites were analyzed. The granites are divided into two groups： fluorite-bearing and fluorite-barren granites. The fluorite-bearing granites are mainly biotite granites, high potassium calc-alkaline, whose accessory minerals commonly include fluorite. The fluorite-bearing granites have higher Mo contents and lower Th/U ratios than those of the fluorite-barren counterparts. Biotite in the fluorite-bearing granites is ferruginous biotite and siderophyllite biotite, which are characterized by higher contents of TiO2, MgO, Cl, and F and lower contents of Al2O3, TFe2O3 than those of the fluorite-barren granites. F and Cl contents of the fluorite-bearing granites show an obvious positive correlation, while the F and Al2O3 contents negatively correlated. The compositions of the biotites indicate that the fluorite-bearing granites were mainly derived from crustal sources with involvement of the mantle, and crystallized at conditions of high temperature, low pressure and high fO2.

关 键 词：南岭 萤石矿 花岗岩 地球化学 黑云母 电子探针 成矿专属性 

分 类 号：P612[天文地球—矿床学] P595[天文地球—地质学]