内蒙古哈达门沟地区泥盆纪金(钼)矿化事件厘定的同位素证据  

Isotopic Evidence for Determining the Devonian Gold and Molybdenum Mineralization in the Hadamengou Area,Baotou,Inner Mongolia

作　　者：侯万荣[1,2] 聂凤军[1] 杜安道[3] 刘翼飞[1] 云飞[1] 张可[1] 刘勇[1] 边红业 刘洪利[2] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]武警黄金第一总队,哈尔滨150086 [3]国家地质实验测试中心,北京100037

出　　处：《地质论评》2011年第4期583-590,共8页Geological Review

基　　金：国家重点自然科学基金资助项目(编号41030421);危机矿山接替资源找矿项目(编号20089948);地质调查项目(编号1212010911029);基本业务费项目(编号K1012)的成果

摘　　要：乌拉山—大青山成矿带为华北板块北缘重要的金成矿带,其中蕴含哈达门沟—柳坝沟大型金(钼)矿田,金(钼)矿床成矿时代和构造背景一直存在争议,长期被认为是中生代构造岩浆活动产物,最近在哈达门沟金矿床深部发现了与金共生的石英脉型和钾化蚀变岩型钼矿化,笔者等利用Re-Os同位素分析方法,首次对与含金黄铁矿共生的辉钼矿进行了年代学研究。4件辉钼矿Re-Os同位素等时线年龄为386.6±6.1M a(MSWD=1.18),加权平均年龄为386.4±2.7M a(MSWD=0.55),初始187Os值为-0.02±0.41。根据以上年龄值,并且结合其它地质证据,可以推测,哈达门沟地区金矿化发生的事件可追溯到早泥盆世,属海西早期构造—岩浆活动事件。上述数据的取得,对重新认识该区金矿成矿作用及区域地质演化历史有着重要的理论和实际意义。Wula Mountains—Daqing Mountains,the important gold mineralization belts in the northern margin of the North China Block,host the large Hadamegou—Liubagou gold—molybdenum orefield,but ore-forming time and tectonic settings of the orefield are still in dispute and the orefield has long been considered the products of tectonic activity during the Mesozoic.Quartz vein-type and potassic alteration-type molybdenum mineralization paragenetic with gold was recently discovered at the depth of the Hadamengou gold deposit.Re-Os isotopic method in this study was employed to chronologically determine molybdenite paragenetic with Au-bearing pyrite.Four samples of molybdenite yielded an isochrone age of 386.6±6.1 Ma（MSWD=1.18）,with a weighted average of 386.4±2.7 Ma（MSWD=0.55）and an initial 187Os value of-0.02±0.41.Combined with other geological evidence,our result suggests that the gold mineralization event at the Hadamengou area could date back to the Early Devonian,which indicates an event of tectonomagmatic activity occurring in the early Hercynian period.The data acquired above are of important significance,both theortically and practically,in further understanding the gold mineralization and regional geological evolution of this area.

关 键 词：泥盆纪金(钼)矿化 辉钼矿RE-OS同位素年龄 哈达门沟金(钼)矿床 内蒙古 

分 类 号：P618.51[天文地球—矿床学]