集宁地区古元古代基性麻粒岩两期变质事件的地质意义  

Geological significance of two-phase isotopic ages of Paleoproterozoic mafic granulites in Jining area

作　　者：常青松 施建荣 张家辉 王惠初 任云伟 CHANG Qing-song;SHI Jian-rong;ZHANG Jia-hui;WANG Hui-chu;REN Yun-wei(Tianjin Centre,China Geological Survey,Tianjin 300170,China;Pre-Cambrain Geological Research Centre,China Geological Survey,Tianjin 300170,China)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]中国地质调查局前寒武纪地质研究中心,天津300170

出　　处：《华北地质》2022年第2期68-75,共8页North China Geology

基　　金：中国地质调查局项目:“华北地区区域基础地质调查(DD20221631)”;“河北怀安-内蒙凉城地区区域地质调查(DD20190035)”;“燕山-太行成矿带丰宁和天镇地区地质矿产调查(DD20160042)”。

摘　　要：古元古代基性麻粒岩一直是华北克拉通构造演化的研究热点之一。近些年来,笔者参与的1/5万地质调查工作显示:集宁地区古元古代基性麻粒岩存在两期年龄信息,早期1.96 Ga~1.91Ga记录了基性岩浆侵位-超高温麻粒岩相变质-麻粒岩相变质的演化过程,与孔兹岩系超高温变质及重熔花岗岩的形成关系密切,该期岩浆事件与区域上~1.95 Ga高压麻粒岩相变质年龄一同记录了造山碰撞-局部伸展-碰撞后伸展的演化过程;晚期记录了1.85 Ga~1.80 Ga的变质事件,该期事件影响广泛,可能为挤压造山事件。Paleoproterozoic mafic granulites have been one of the research hotspots in tectonic revolution of North China Craton.Recent 1/50000 regional geological survey in which the author has participated has shown that there are two phases of age information for the Paleoproterozoic mafic granulites in Jining area.The early phase is 1.96 Ga~1.91 Ga,which records the evolution of emplacement of the protoliths of the mafic granulites,the ultra-high temperature metamorphic of the khondalites and origin of the remelted granites and the simultaneously granulite-high amphibolite facies metamorphism.This phase of magmatic event,together with the regional~1.95 Ga high-pressure granulite metamorphic ages,records the evolution of the orogenic collision-postcollisional extension.The later phase is the 1.85 Ga~1.80 Ga metamorphic age,possibly indicating the widespread influence of the~1.85 Ga extrusive orogenic event.

关 键 词：高压基性麻粒岩 基性岩墙 华北克拉通 古元古代 

分 类 号：P588.3[天文地球—岩石学]