西天山塔乌尔别克金矿成矿作用：Re-Os年龄和S-Pb同位素示踪  

Origin and metallogenesis of the Tawuerbieke gold deposit,western Tianshan:Insight from Re-Os geochronology and S-Pb isotopic compositions

作　　者：赵晓波[1,2] 薛春纪[1,2] 门启浩 闫永红 王洪刚[1,2] 俎波[1,2] 米登江 李晓忠[4] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院 [2]地质过程与矿产资源国家重点实验室,北京100083 [3]中信矿业科技发展有限公司,北京100004 [4]中国冶金地质总局 新疆地质勘查院,新疆乌鲁木齐830006

出　　处：《地学前缘》2014年第5期176-186,共11页Earth Science Frontiers

基　　金：国家自然科学基金项目(U1303292);国家科技支撑计划项目(2011BAB06B02);中国地质调查局地质大调查项目(1212011085069,121211220926);新疆中亚造山带大陆动力学与成矿预测重点实验室开放基金项目(XJDX1102-2012-06)

摘　　要：塔乌尔别克金矿床位于哈萨克斯坦—伊犁板块东北部边缘吐拉苏盆地中部,金矿化赋存于下石炭统大哈拉军山组火山岩和花岗斑岩中,属于冰长石-绢云母型浅成低温热液金矿床。金矿体呈不连续脉状-透镜状,受NNW或近SN向断裂或它们交汇部位控制。金成矿经历了早期的面型热液蚀变和后期石英-方解石-黄铁矿脉叠加。自然金常包裹于黄铁矿晶体内,与黄铁矿为同期形成产物。载金黄铁矿Re-Os法测年获得等时线年龄为（323±11）Ma（MSWD=4.2）,187 Os/188 Os（i）初始值为0.17±0.19,金矿石δ34 SV-CDT=2.0‰～4.2‰,206Pb/204Pb=17.931～18.229,207Pb/204Pb=15.599～15.670,208Pb/204Pb=37.980～38.980,显示成矿金属物质为壳幔混合来源且以幔源岛弧岩浆（即大哈拉军山组火山岩）为主,金成矿晚于赋矿围岩约40Ma,浅成低温热液型金矿化与北天山洋关闭向陆-陆碰撞转换的动力学过程有关。The Tawuerbieke gold deposit is located in the central part of the Tulasu basin, northeast margin of the Kazakhstan-Yili plate. Gold mineralization was hosted by volcanic rocks of the Early Carboniferous Dahalajunshan Formation and granitic porphyries, and belongs to the Adularia-Sericite Epithermal gold type. The mineralized shoots occurred as discontinuous veins and lenses that were controlled by NNW and nearly NS-trending faults, preferentially at their intersections. The mineralization can be divided into two types and stages. The early-stage, low-grade, fracture-controlled type of mineralization was associated with pervasive alteration that included pyrite, sericite, carbonate, chlorite, epidote and quartz. This type of mineralization was overprinted by late-stage quartz-calcite-pyrite veins. Native gold occurred as enfoldment state existing in pyrite, suggesting that they were formed in the same mineralization stage. Re-Os dating of five gold bearing pyrite samples yielded an isochrone age of the 323± 11 Ma （MSWD=4.2）, with radiogenic initial 187 Os/188 Os of 0. 17±0.19. The ore δ34 Sv-cdt is from 2. 0%o to 4. 2%0, 206Pb/204 Pb from 17. 931 to 18. 229, 207Pb/204Pb from 15. 599 to 15. 670, and 208Pb/204 Pb from 37. 980 to 38. 980, indicating that the metal was sourced from both mantle and crust, with a dominant component of mantle-derived island-arc magma （mantle-derived volcanic rocks of the Dahalajunshan Formation）. The time gap between emplacement of the host rocks and gold mineralization is about 40 Ma. Epithermal gold mineralization in the Tulasu basin was formed in a tectonic switch from subduction to post collision.

关 键 词：浅成低温热液金矿 成矿年龄 塔乌尔别克金矿 吐拉苏盆地 新疆西天山 

分 类 号：P618.51[天文地球—矿床学] P597[天文地球—地质学]