内蒙古宝格达乌拉钼(钨)矿区花岗岩锆石SHRIMP U-Pb年龄及地质意义  

Zircon SHRIMP U-Pb dating and geological significance of granite in the Baogeda Ula Mo(W) mining area,Inner Mongolia,China

作　　者：刘勇[1,2] 聂凤军[1] 刘翼飞[1] 侯万荣[1,3] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]北京科技大学,北京100083 [3]中国人民武装警察部队黄金第一总队,哈尔滨150086

出　　处：《岩石学报》2012年第2期401-408,共8页Acta Petrologica Sinica

基　　金：国家重点自然科学基金项目(41030421);地质调查项目(1212010911029)联合资助

摘　　要：本文首次对新发现的宝格达乌拉钼(钨)矿区中含矿花岗岩的锆石进行了SHRIMP U-Pb定年,获得9个锆石颗粒的206Pb/238U年龄的加权平均值为240.9±2.5Ma,MSW值为1.7,上述数值表明岩体形成时代应为印支期。根据野外实地勘查以及进一步室内研究工作,可以初步推测出,该地区在中生代时期曾经发生过古陆块内部拉张作用,由此所诱发的大规模构造-岩浆活动及相关流体活动为该区钼(钨)矿床的形成提供了物质、动力和热力来源。区内含矿花岗岩即是此次构造-岩浆作用产物。除此之外,由于宝格达乌拉地区位于早期西伯利亚板块和华北板块相互俯冲和碰撞的交界处,区域内花岗岩体在形成过程中受到了多期次岩浆热液作用的影响,因此在对区域内锆石年龄及相关微量元素进行测定时发现,该区域内含矿岩体岩性复杂,表现出了一定的继承性。这也为研究人员对二连浩特-东乌珠穆沁旗一带矿床成因作用的进一步研究提供了重要参考。Its the first time that the zircon SHRIMP U-Pb dating of granite in the Baogeda Ula Mo（W） mining area which is found recently,and obtain the weighted average age of the nine zircons is 240.9±2.5Ma,the MSW is 1.7,Indosinian.According to the fieldwork and indoor studies,we could speculate that the extension of ancient land mass in Mesozoic occurred in this area.Large scale tectonic-magmatic activities and related to fluid which induced by the extension provide the material,power and heating sources for the deposit in Baogeda Ula Mo（W） mining area.The granite in this area is the result of tectonic-magmatic activities.Beyond that,we found the ore-bearing rock with complex lithological characters and some succession characters.It’s because of that this area is at the junction after the subduction and collision between Early Siberian plate and the North China plate.Its also provide important reference for the genesis research of deposit in Erlianhaote-East Wuzhumuqinqi belt.

关 键 词：花岗岩 锆石SHRIMP U-PB定年 宝格达乌拉 内蒙古 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学]