收稿日期:2022-10-18;修订日期:2023-02-13作者简介:钟炽涛(1998—),男,硕士研究生,专业方向:地质学。基金项目:大兴安岭成矿带南段地质矿产调查项目(1212011120718);环境重点实验室开放基金项目(NRE1403)。第41卷第1期2023年2月江西科学JIANGXISCIENCEVol.41No.1Feb.2023doi:10.13990/j.issn1001-3679.2023.01.024华北克拉通乌拉山地区古元古代含磁铁矿伟晶岩脉年代学特征及地质意义钟炽涛(东华理工大学地球科学学院,330013,南昌)摘要:华北克拉通北缘构造活动频繁,特别是从太古宙到印支期,伴随着山前大断裂的多次活动,形成了多期次的岩浆侵入体或岩脉。以内蒙古乌拉山地区含磁铁矿伟晶岩脉为研究对象,通过LA-ICP-MS锆石U-Pb测年技术,精确测定了含磁铁矿伟晶岩形成时代为(1817±18)Ma,为古元古代鄂尔多斯陆块与阴山陆块碰撞的背景下,孔兹岩系发生深熔作用形成的产物,其形成、演化与“吕梁运动”密切相关,代表了华北克拉通北缘1.85―1.7Ga的裂解事件。关键词:含磁铁矿伟晶岩脉;锆石U-Pb定年;古元古代;乌拉山地区中图分类号:P618.510.5文献标识码:A文章编号:1001-3679(2023)01-140-05ChronologicalCharacteristicsandGeologicalSignificanceofPaleoproterozoicMagnetite-BearingPegmatiteDykesintheWulaMountainsoftheNorthChinaCratonZHONGChitao(SchoolofEarthSciences,EastChinaUniversityofTechnology,330013,Nanchang,PRC)Abstract:IntheNorthChinacratonnorthernmargintectonicactivitiesarefrequent,especiallyfromtheArcheantotheIndochineseperiod,accompaniedbythemultipleactivitiesofthepre-mountainfault,theformationofmultiplestagesofmagmaticintrusionordike.Takingthemagnetite-bearingpegmatitesintheUlaMountainsareaofInnerMongoliaastheresearchobject,thispaperaccuratelydeterminedtheformationageofmagnetite-bearingpegmatitesas(1817±18)MabyLA-ICP-MSZirconU-Pbdatingtechnology,whichistheproductofdeepmeltingintheKunzirocksystemunderthebackgroundofthecollisionbetweenthePaleoproterozoicOrdoslandmassandtheYinMountainlandmassif,anditsformationandevolutionarecloselyrelatedtothe“Lüliangmovement”,representingthecrackingeventof1.85―1.7GainthenorthernmarginoftheNorthChinacraton.Keywords:magnetite-bearingpegmatitedikes;Zircon...