新疆东天山玉海铜矿蚀变矿化特征及SWIR勘查应用研究  

Alteration and Mineralization of the Yuhai Cu Deposit in Eastern Tianshan,Xinjiang and Applications of Short Wavelength Infra-Red(SWIR)in Exploration

作　　者：陈寿波 黄宝强 李琛 田庆磊 王超 吴见新 陈明霞 韩金生[2] 冯雨周 王云峰[2,3] Chen Shoubo;Huang Baoqiang;Li Chen;Tian Qinglei;Wang Chao;Wu Jianxin;Chen Mingxia;Han Jinsheng;Feng Yuzhou;Wang Yunfeng(No.704 Geological Party,Xinjiang Geological Exploration Bureau for Nonferrous Metals,Hami 839000,China;Key Laboratory of Mineralogy and Metallogeny,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]新疆维吾尔自治区有色地质勘查局七0四队,新疆哈密839000 [2]中国科学院广州地球化学研究所矿物学与成矿学重点实验室,广东广州510640 [3]中国科学院大学,北京100049

出　　处：《地球科学》2018年第9期2911-2928,共18页Earth Science

基　　金：新疆维吾尔自治区地质勘查基金项目(No.T13-3-XJ27)

摘　　要：玉海铜矿位于东天山大南湖-头苏泉岛弧带的东段,是新疆有色地勘局704队近年来发现的一中型铜矿床,但人们对其蚀变和矿化分布特点、矿床成因类型依然知之甚少.基于详细的矿床地质、黑云母和绢云母Ar-Ar同位素定年及短波红外光谱(SWIR)研究,结果表明矿区蚀变主要有黑云母-磁铁矿化、绢英岩化及绿泥石化.其中,黑云母-磁铁矿化在矿区石英闪长岩中均有分布;绢英岩化出现在石英闪长岩中,呈带状分布;绿泥石化在石英闪长岩中均有分布,但在黑云母-磁铁矿化与绢英岩化接触部位,绿泥石化最强.黄铜矿化主要以黄铜矿-黄铁矿-磁铁矿、绿帘石-黄铜矿组合的形式出现,前者与黑云母-磁铁矿化关系密切,后者与绢英岩化关系密切.黑云母及绢云母^(40)Ar/^(39)Ar定年得到的年龄为324~314Ma,与矿区出露的花岗岩年龄(325.4±2.5Ma)在误差范围内相似,但地质条件表明矿区黑云母及绢云母Ar-Ar体系均可能被后期岩浆作用重置,结合前人研究成果,玉海铜矿化可能形成于360~350 Ma.此外,矿区绿泥石Fe-OH特征峰位值(Pos2250)的高值(>2 253nm)主要分布在绢英岩化带及其附近,且与矿体位置相近,可作为玉海矿区找矿勘查的标志.The Yuhai Cu deposit,recently discovered by the No.704 Geological Party of Xinjiang Geological Exploration Bureau for Nonferrous Metals,is located in the eastern part of the Dananhu-Tousuquan island arc belt,eastern Tianshan.The alteration and mineralization features,and metallogenesis of the Yuhai deposit are still controversial.Detailed studies on ore geology,biotite and sericite Ar-Ar isotopic dating,and short wavelength infra-red（SWIR）indicate that biotite-magnetite,phyllic and chlorite alteration are well developed at Yuhai.The biotite-magnetite alteration extensively occurs in the quartz diorite,thephyllic alteration zone mainly occurs in the quartz diorite,and the chlorite alteration mainly occurs in the transitional zone of biotite-magnetite and phyllic alterations belts.Chalcopyrite mineralization occurs as chalcopyrite-pyrite-magnetite and epidotechalcopyrite assemblages,and the former is closely related to the biotite-magnetite alteration,while the latter is associated with the phyllic alteration.The results of biotite and sericite ^（40） Ar/^（39） Ar dating are ca.324-314 Ma,consistent with the age of Yuhai granite（325.4±2.5 Ma）in errors.Integrating with local geology,biotite and sericite Ar-Ar systems were likely reset after their formation.Combined with previous studies,the biotite-magnetite and phyllic alterations were likely formed at 360-350 Ma,related with the emplacement of the Yuhaixi gneissic granite（or other coeval intrusions）.Short wavelength infra-red（SWIR）research at Yuhai reveals that high values（〉2 253 nm）of chlorite Fe-OH absorption peak（Pos2250）mainly occur in the phyllic alteration zone and its adjacent areas,pointing to the Cu bodies,which can be used as a potential exploration tool in deposit-scale.

关 键 词：东天山 玉海铜矿 40Ar/39Ar定年 短波红外光谱 年代学 

分 类 号：P614[天文地球—矿床学]