哈勒盖图地区白音高老组流纹岩岩石地球化学特征及其地质意义  

Geological significance and geochemical characteristics of rhyolites in Baiyingaolao Formation at Halegaitu of Xiwuqi,Inner-Mongolia

作　　者：程天赦[1,2] 杨文静[2] 王登红[3] 肖盈[4] 张全[2] 

机构地区：[1]中国地质大学地球科学与资源学院,北京100083 [2]天津市地质调查研究院,天津300191 [3]中国地质科学院资源所,北京100083 [4]中原油田普光分公司采气厂,四川达州636156

出　　处：《辽宁工程技术大学学报（自然科学版）》2012年第4期489-493,共5页Journal of Liaoning Technical University (Natural Science)

基　　金：中国地质调查局内蒙古1:5万区域地质调查资助项目([2010]矿评01-19-01号)

摘　　要：在样品采集和分析基础上,探讨内蒙古西乌旗哈勒盖图地区早白垩世白音高老组流纹岩的岩石地球化学特征及其地质意义.主量元素分析结果显示其具有高硅、富碱、高铝、低MgO、CaO、TiO2、MnO的特征,稀土元素与微量元素地球化学特征显示其类似于A型花岗岩特征;低Ti/Y、Nb/Y与Ti/Zr比值、高Rb/Nb与Rb/Y比值以及Sr、Eu强烈亏损,表明其为上地壳物质部分熔融成因,形成于早白垩世非造山板内伸展环境.研究结论揭示了该时期大兴安岭地区构造-岩浆的重要作用,对该地区今后的找矿工作具有重要的指导意义.This paper will discuss the geological significance and geochemical characteristics of rhyolites in Baiyingaolao Formation at Halegaitu of Xiwuqi on the basis of sample collection and analysis.Major element analysis results demonstrate that the rhyolites is characterized by high SiO2,rich in total alkaline,high Al2O3,low MgO,low CaO,low TiO2,and low MnO.The geochemical characteristics of REE and trace elements are similar to the A-type granite.The characteristics of low Ti/Y,low Nb/Y,low Ti/Zr,high Rb/Nb,high Rb/Y,and strong depletion in Sr and Eu indicate that the rhyolitic magma was originated from the partial melting of basaltic upper crustal materials.Combining with the regional results,it suggests that the rhyolites were formed in an intra-plate anorogenic extensional setting.The study finds that the period structure-magma plays an important role in Daxinganling region,which is of significance in guiding the future prospecting work in the region.

关 键 词：钙-碱性流纹岩 A型花岗岩 地球化学 白音高老组 西乌旗 构造背景 岩石学特征 岩石成因 

分 类 号：P58[天文地球—岩石学]