南岭中段主要锡矿床He、Ar同位素组成及其意义  

He and Ar Isotopic Components of Main Tin Deposits from Central Nanling Region and Its Signification

作　　者：刘云华[1] 付建明[1] 龙宝林[2] 魏君奇[1] 刘国庆[1] 杨晓君[1] 杨永强[2] 

机构地区：[1]宜昌地质矿产研究所,湖北宜昌443003 [2]中国地质大学地球科学与资源学院

出　　处：《吉林大学学报（地球科学版）》2006年第5期774-780,786,共8页Journal of Jilin University：Earth Science Edition

基　　金：中国地质调查局矿产资源评价计划项目(资[2004]035)下设的工作项目(200310200072)

摘　　要：对南岭中段主要锡矿床的黄铁矿等进行了流体包裹体的He、Ar同位素研究。结果表明，成矿流体的^40Ar／^36Ar≈288～371，^3He／^4He≈0．09～28．58Ra，不同地区流体包裹体He、Ar浓度变化较大，而在同一地区^40Ar／^36Ar、^3He／^4He值比较一致；^40Ar／^36Ar值介于大气饱和水（包括大气降水和海水）的同位素组成（^40Ar／^36Ar≈295．5）和夏威夷热点（^40Ar／^36Ar=350～360）之间^3He／^4He值大大高于大陆地壳特征值（^3He／^4He≈0．03Ra），介于地壳特征值与原始地幔特征值（^3He／^4He≈8．57Ra）和夏威夷热点特征值（^3He／^4He≈27．14Ra）之间，表明成矿流体与地慢柱的活动有关，为地幔、地壳和大气水的混合产物，以地幔流体为主。这一结果为南岭地区锡多金属矿床为壳幔相互作用的产物及区域地慢柱的存在提供了新证据．He and Ar isotopic components of the fluid inclusions in pyrites from the main tin deposits in the central Nanling region are studied to discuss the genesis and material sources of these deposits. The results indicate that the ^40Ar/^36Ar ratio varies between 288 and 371 and ^3He/^4He 0.09～28.58 Ra. He and Ar concentrations change greatly in different area while ^40Ar/^36Ar and ^3He/^4 He ratios are more consistent in the same area. ^40Ar/^36Ar ratios are between that of the atmosphere saturation water（including meteoric precipitation and seawater） （^40Ar/^36Ar≈ 295.5） and that of Hawaii hotspot （^40Ar/^36Ar=350～ 360） ; Their ^3He/^4He ratios are apparently above those of the continental crust （^3He/^4He≈ 0.03Ra） and are within the range of the averaged crust, of the primitive mantle（^3He/^4He≈8.57 Ra） and of the characteristic Hawaii hotspot （^3 He/^4 He≈27.14 Ra）. Above features indicate that the metal- logenic fluids are related to the activation of the mantle plume, and they probably are the mixing product of the mantle-and crust-derived fluids and of the meteoric water. The results provide new evidences that the tin deposits are product of the crust-mantle interaction and that the mantle plumes had existed in the Nanling region.

关 键 词：He、Ar同位素 流体包裹体 锡矿 南岭中段 

分 类 号：P618.44[天文地球—矿床学]