华北克拉通中北部麻粒岩带基础地质调查进展及相关问题讨论  

Geological survey of granulite belt in the north-central part of North China Craton:progress and discussion on related problems

作　　者：王惠初 张家辉 任云伟 施建荣 相振群[1,2] 常青松 王智 WANG Hui-chu;ZHANG Jia-hui;REN Yun-wei;SHI Jian-rong;XIANG Zhen-qun;CHANG Qing-song;WANG Zhi(Tianjin Center,China Geological Survey,Tianjin 300170,China;Precambrain Geological Research Centre,China Geological Survey,Tianjin 300170,China;International Mining Research Center,China Geological Survey,Beijing 100037,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 [3]中国地质调查局国际矿业研究中心,北京100037

出　　处：《华北地质》2022年第1期18-41,共24页North China Geology

基　　金：中国地质调查局项目:“燕山-太行成矿带丰宁和天镇地区地质矿产调查(DD20160042)”;“河北怀安-内蒙古凉城地区区域地质调查(DD20190035)”;国家青年科学基金项目(41902196)联合资助。

摘　　要：华北克拉通中北部麻粒岩带被认为是古元古代造山带,晋冀蒙相邻地区的高压麻粒岩和超高温变质岩吸引了国内外早前寒武纪地质学家的目光。本文以区域地质调查资料为基础,重新厘定了华北克拉通中北部的构造单元,自北向南依次划分为阴山新太古代岩浆弧(阴山地块)、乌拉山-大青山古元古代再造杂岩带(Pt_(1))、凉城深熔花岗岩带(Pt_(1))、天镇-怀安再造杂岩带(Pt_(1))和五台新太古代岛弧带。梳理了古元古代造山带三个构造单元的地层系统和主要构造热事件,认为乌拉山-大青山古元古代再造杂岩带和天镇-怀安再造杂岩带在物质组成和构造热事件记录上具有可比性。通过地质填图,将凉城深熔花岗岩划分为3期6种岩石类型,并发现了不含石榴石的紫苏花岗闪长岩(石英闪长岩),具有钙碱性系列I型花岗岩特征。根据钻孔资料结合航磁特征探讨了鄂尔多斯盆地变质基底的构造属性,认为古元古代造山带的构造线切割了鄂尔多斯盆地基底,鄂尔多斯基底不是一个太古宙地块。综合分析古元古代变质作用、岩浆作用和构造变形作用,认为古元古代造山带经历了大陆裂解、俯冲碰撞、板片拆沉-地幔上涌、挤压造山和造山后伸展抬升的复杂演化过程,反映了早期热板块构造的特殊性。The granulite belt in the north-central North China Craton is considered to be a Paleoproterozoic orogenic belt.The high-pressure granulite and ultra-high temperature metamorphic rocks in the adjacent areas of Shanxi,Hebei and Inner Mongolia have attracted the attention of Early Precambrian geologists around the world.Based on the regional geological survey data,this paper redefines the tectonic unit in the north central part of the North China Craton,which is divided into Yinshan Neoarchean magmatic arc(Yinshan block),Daqingshan-Wulashan Paleoproterozoic reworking complex belt(Pt_(1)),Liangcheng deep melt granite belt(Pt_(1)),Tianzhen-Huai'an reworking complex belt(Pt_(1))and Wutai Neoarchean island-arc belt from north to south.The stratigraphic system and main tectonic thermal events in the three tectonic units of the Paleoproterozoic orogen are redefined.It is considered that the Daqingshan-Wulashan Paleoproterozoic and Tianzhen-Huai'an reworking complex belt are comparable in material composition and records of tectonic thermal events.Through geological mapping,the anatexis granite was formed in three stages and divided into six kinds of rock types,and Opxbearing granodiorite(quartz-diorite)without garnet is found,which is characterized by calc alkaline series I-type granite.Based on borehole data and aeromagnetic characteristics,the structural properties of metamorphic basement of Ordos Basin are discussed.It is considered that the tectonic line of the Paleoproterozoic orogenic belt cuts the basement of the Ordos Basin,and the Ordos basement is not an Archean block.Based on the comprehensive analysis of Paleoproterozoic metamorphism,magmatism and tectonic deformation,it is considered that the Paleoproterozoic orogenic belt has experienced the complex evolution process of continental breakup,subduction collision,plate delamination,mantle upwelling,compression orogeny and post orogenic extension and uplift,which reflects the particularity of Early hot-plate tectonics.

关 键 词：华北克拉通 麻粒岩带 构造单元 深熔花岗岩 孔兹岩系 古元古代 

分 类 号：P588.3[天文地球—岩石学] P545[天文地球—地质学]