厄立特里亚Augaro金矿床碳氢氧硫同位素特征及其成因意义  

Studies on C-H-O-S isotopes of Eritrea Augaro gold deposit and its implications for gold genesis

作　　者：向文帅 赵凯[2] 张紫程 XIANG Wenshuai;ZHAO Kai;ZHANG Zicheng(China University of Geosciences(Beijing),School of Earth Science and Resources,Beijing,100083;Wuhan Center of China Geological Survey,Wuhan,430205;China Geological Mining Company Ltd.,Beijing,100029)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质调查局武汉地质调查中心,武汉430205 [3]中国地质矿业有限公司,北京100029

出　　处：《地质学报》2021年第4期1284-1291,共8页Acta Geologica Sinica

基　　金：中国地质调查局项目“北部非洲大型铜金资源基地评价”(编号DD20190443),“尼日利亚锡铌钽锂资源调查”(编号DD20201152)项目资助的成果。

摘　　要：厄立特里亚Augaro金矿床产于努比亚地盾新元古代变质火山岩中,矿体主要赋存于片理化安山岩内,受北北东向断裂与近东西向次级断裂控制。对矿床主要含金石英脉型矿石与蚀变岩型矿石进行碳氢氧硫同位素研究显示,成矿流体的δDw-H_(2)O范围为-68.7‰~-49.4‰,δ^(18)Ow-H_(2)O范围为-1.9‰~4.9‰,δ^(13)CV-PBD范围为-15.9‰~-10.9‰,石英脉型金矿石硫同位素组成以较小的正值为特征,变化范围为0.18‰~0.63‰,而蚀变岩型金矿石硫同位素组成偏低,以较大负值为特征,变化范围为-7.07‰~-6.86‰,表明Augaro金矿床成矿流体主要来源于变质热液,伴有岩浆水与大气降水的混合,矿区地层与岩浆物质为金矿床的形成提供大量成矿物质。The Augaro gold deposit in Eritrea is located in the Neoproterozoic metavolcanic rocks of the Nubian Shield.The ore body is mainly controlled by a NNE primary fault and near-EW secondary faults,occurring in the foliated andesite.C,O and S isotope studies of the main gold-bearing quartz vein and the altered rock ore show that theδDw-H_(2)O range of the ore-forming fluid is-68.7‰~-49.4‰and theδ^(18)Ow-H_(2)O range is-1.9‰~4.9‰,the range ofδ^(13)Cv-PBD is-15.9‰~-10.9‰.The S isotope composition of gold-bearing quartz vein is characterized by a small positive value with a range of 0.18‰~0.63‰.The S isotope composition of altered rock ore is low,characterized by a large negative value,ranging from-7.07‰~-6.86‰,indicating that the ore-forming fluid of the Augaro gold deposit mainly comes from metamorphic hydrothermal fluids,accompanied by a mixture of magmatic water and meteoric precipitation.The stratum formations and magmatic rocks in the research area provide a large amount of ore-forming materials for the gold deposit.

关 键 词：非洲 厄立特里亚 金 石英脉 蚀变岩 稳定同位素 

分 类 号：P618.51[天文地球—矿床学]