陕西凤太矿集区柴蚂金矿床脉状闪锌矿Rb-Sr同位素测年及意义  

Rb-Sr isotopic Dating of Vein-like Sphalerites from the Chaima Au Deposit in Fengxian-Taibai Ore-concentration Area,Shaanxi Province and Its Geological Significance

作　　者：王义天[1] 刘协鲁 胡乔青[1] 张娟 陈绍聪 王瑞廷 代军治 高卫宏 温深文 陈明寿 张革利 WANG Yitian1,LIU Xielu2,HU Qiaoqing1,ZHANG Juan3,CHEN Shaocong1,WANG Ruiting4,DAI Junzhi4,GAO Weihong5,WEN Shenwen5,CHEN Mingshou5,ZHANG Geli5(1. Key Laboratory ofMetallogeny and Mineral Assessment,MLR,Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China; 2. Beijing Institute of Exploration Engineering,Beijing 100083,China;3. School of Resources,Hebei GEO University,Shijiazhuang 050031,Hebei,China ; 4. Northwest Geological Exploration and Mining Bureau for Nonferrous Metals,Xi’an 710054,Shaanxi,China ; 5. No. 717 Geological Party,Northwest Geological Exploration and Mining Bureau for Nonferrous Metals,Baoji 721004,Shaanxi,China)

机构地区：[1]中国地质科学院矿产资源研究所、国土资源部成矿作用和资源评价重点实验室,北京100037 [2]北京探矿工程研究所,北京100083 [3]河北地质大学,河北石家庄050031 [4]西北有色地质勘查局,陕西西安710054 [5]西北有色地质勘查局717总队,陕西宝鸡721004

出　　处：《西北地质》2018年第3期121-132,共12页Northwestern Geology

基　　金：国家自然科学基金项目“西秦岭凤太矿集区金矿与铅锌矿的成矿作用关系研究”(41372089); 中国地质调查局地质调查工作项目“秦岭-大巴山-大别山成矿规律及找矿方向研究”(1212011220869)联合资助

摘　　要：柴蚂金矿床位于陕西省凤太矿集区西北部八卦庙超大型金矿床的西侧约0.5km处,二者在成矿地质背景和控矿条件等方面均相似。该矿床共划分出5个含矿带,其产出位置受地层和构造联合控制。本次工作对柴蚂金矿床中发育的脉状闪锌矿进行了Rb-Sr同位素测年研究,获得了等时线年龄为(210.8±2.4)Ma,即晚三叠世;闪锌矿的^(87)Sr/^(86)Sr_i值为0.710 55±0.000 11,指示铅锌矿化的成矿物质可能主要来源于大陆壳。结合前人的研究成果分析认为,凤太矿集区内的铅锌矿化和金矿化是在秦岭造山带印支期碰撞-后碰撞过程中同一时代同一成矿作用的产物。The Chaima gold deposit is located at the northwest part of the Fengxian-Taibai oreconcentration area in Shaanxi Province,it is 0.5km west to the super-large Baguamiao gold deposit,and both of them are similar in metallogenic geological environment and ore-controlling conditions.There are five ore-bearing zones in this deposit and their occurrences are controlled by both of lithology and structure.In this paper,the Rb-Sr isotopic dating has been carried out on the sphalerite from the sphalerite-galena vein of the main mineralization stage in the Chaima Au deposit,yielding an isochron age of（210.8±2.4）Ma,showing that the zinc mineralization was developed in Late Triassic.The ^（87）Sr/^（86）Sr_iratio of the sphalerite is 0.710 55±0.000 11,indicating that the ore-forming materials are mainly derived from the continental crust.In the context of regional geology,it＇s suggested that lead-zinc mineralization and gold mineralization in the Fengxian-Taibai ore-concentration area are the common products in the Late Triassic collision process of the South Qinling orogenic belt,and the gold deposits and lead-zinc deposits are formed at the same era.

关 键 词：脉状闪锌矿 Rb-Sr同位素测年 柴蚂金矿床 凤太矿集区 陕西省 

分 类 号：P618.51[天文地球—矿床学]