西秦岭江里沟钨铜钼多金属矿床地质特征及辉钼矿Re-Os同位素年龄  

Geological Features and Molybdenites Re-Os Isotopic Dating of the Jiangligou W-Cu-Mo Polymetallic Deposit,West Qinling

作　　者：路东宇 叶会寿[2] 于淼[2,3] 杨兵[4] 王生龙 张捷先[1] 抄尉尉 王鹏[1] 

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]中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点开放实验室,北京100037 [3]北京大学地球与空间科学学院,北京100871 [4]西部矿业股份有限公司,西宁810001 [5]青海省有色金属地质矿产勘查局七队,西宁810600

出　　处：《地质学报》2015年第4期731-746,共16页Acta Geologica Sinica

基　　金：全国重要成矿区带矿产区划部署综合研究(编号12120114051401);西部矿业股份有限公司科研专项"青海省同仁县江里沟铜钨矿控矿因素研究及找矿靶区厘定专题研究"资助成果

摘　　要：近些年探明的江里沟大型钨（铜钼）多金属矿床位于青海省同仁县,地处秦岭造山带西段勉-略缝合带以北岗察复式岩体西北缘,属斑岩-矽卡岩型钨铜钼多金属矿床。矽卡岩型钨（铜钼）矿体主要赋存于江里沟花岗岩体与下二叠统大关山群的大理岩和下三叠统隆务河群凝灰质细粉砂岩的接触带矽卡岩中,呈似层状、透镜状和豆荚状产出。云英岩型钨矿体和斑岩型钼矿体赋存于江里沟花岗岩体中。本次研究选取16件矽卡岩型和斑岩型辉钼矿样品,采用ICP-MS法进行Re-Os同位素定年,获得模式年龄介于215.0±3.0-219.0±3.7 Ma,加权平均年龄为216.85±0.77 Ma,等时线年龄为217±1 Ma（MSWD=1.4）。矿床形成于晚三叠世,属秦岭造山带印支期后碰撞伸展环境构造-岩浆-流体成矿的产物。Jiangligou large porphyry-skarn tungsten （Cu-Mo） polymetallic deposit in Tongren County, Qinghai Province is tectonically located in the northwestern margin of Gangcha pluton in the northern of Mian-Lue suture zone, the western part of the Qinling orogen belt. Skarn tungsten （Cu-Mo） ores mainly occur as bedded, lenticular and pod-shape in the skarn between Jiangligou granite and Lower Permian Daguanshan Group marble or Lower Triassic Longwuhe fine tuffaceous sandstone. Greisenization type of tungsten ore and porphyry copper ore was formed in the Jiangligou granite. Sixteen samples from the three types of ores have been collected for Re/Os dating. The results of Re/Os isotope dating using ICP-MS method show Re/ Os model ages arranging from 215.0±3.0 Ma to 219.0±3.7 Ma, with a weighted average age of 216.85± 0.77 Ma, an isochron age of 217±1 Ma （MSWD=1. 4）. The deposit was believed genetically related to the tectonic-igneous-fliuid during Indosinian mineralization and formed in extension environment, after the collision in the Late Triassic in the Qinling orogen belt.

关 键 词：RE-OS同位素年龄 斑岩-矽卡岩型矿床 印支期成矿作用 江里沟钨铜钼矿床 西秦岭造山带 

分 类 号：P618.2[天文地球—矿床学]