内蒙古白音诺尔铅锌矿床印支期成矿的年代学证据  

Geochronology evidence for Indosinian mineralization in Baiyinnuoer Pb-Zn deposit of Inner Mongolia

作　　者：江思宏[1] 聂凤军[1] 白大明[1] 刘翼飞[1] 刘妍[1] 

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与资源评价重点实验室,北京100037

出　　处：《矿床地质》2011年第5期787-798,共12页Mineral Deposits

基　　金：全国危机矿山项目(编号:20089948);地质大调查项目(编号:1212010911029)联合资助

摘　　要：内蒙古白音诺尔铅锌矿床是大兴安岭地区最大的铅锌矿床,矿体主要沿碳酸盐岩与花岗闪长岩的接触带产出。对矿区内及外围主要岩体的锆石LA-MC-ICP-MS测年结果表明,矿区外围花岗岩岩基的形成年龄为(134.8±1.2)Ma(MSWD=2.40),矿区内花岗闪长岩的形成年龄为(244.5±0.9)Ma(MSWD=0.85),石英斑岩为(129.2±1.4)Ma(MSWD=5.5)。这说明,白音诺尔铅锌矿的矿化蚀变发生在花岗闪长岩的就位过程中,成矿时代为印支早期,而不是前人认为的燕山早期,但受到燕山晚期岩浆活动影响,有成矿作用的叠加。The Baiyinnuoer ore deposit in Inner Mongolia is the largest Pb-Zn deposit in the Da Hinggan Mountains.The ore bodies in this ore deposit mainly occur along the contact zone between the granodiorite and the carbonate rock.In order to constrain the emplacement age of the intrusive rocks within and around the Baiyinnuoer Pb-Zn deposit,the authors dated the zircons of four samples from the intrusive rocks by using the LA-MC-ICP-MS method.Three reliable weighted mean 206Pb/238U ages of（134.8±1.2） Ma（MSWD=2.40）,（244.5±0.9） Ma（MSWD=0.85）,and（129.2±1.4） Ma（MSWD=5.5） were obtained from the granite batholiths around the Baiyinnuoer ore deposit,granodiorite and quartz porphyry in the ore deposit,respectively.These data indicate that the main Pb-Zn mineralization in the Baiyinnuoer ore deposit took place during the early Indosinian epoch instead of during the early Yanshannian epoch considered by previous researches.The superimposed mineralization might have taken place in the ore deposit during the late Yanshannian epoch,as evidenced by the dating result in this paper.

关 键 词：地球化学 LA-MC-ICP-MS锆石测年 印支期 白音诺尔 内蒙古 

分 类 号：P618.42[天文地球—矿床学] P618.43[天文地球—地质学]