冀北镇宁堡—赤城一带红旗营子杂岩变基性岩及其围岩锆石U-Pb年代学研究  

Zircon U-Pb chronology of meta-basic rock and its surrounding rock of Hongqiyingzi complex,Zhenningpu-Chicheng area,the north Hebei province

作　　者：孔旭 密文天 马莹莹 辛杰 卢嵩 邢佳怡 李诗佳 王晟宁 KONG Xu;MI Wentian;MA Yingying;XIN Jie;LU Song;XING Jiayi;LI Shijia;WANG Shengning(Department of Geology, Northwest University, Xi’an 710069, China;School of Mines, Inner Mongolia University of Technology, Hohhot 010051, China)

机构地区：[1]西北大学地质学系,西安710069 [2]内蒙古工业大学矿业学院,呼和浩特010051

出　　处：《地质找矿论丛》2021年第3期297-307,共11页Contributions to Geology and Mineral Resources Research

基　　金：内蒙古自然科学基金项目(编号:2019LH04002,2020MS04009);内蒙古工业大学教材建设项目(编号:JC201712);内蒙古自治区研究生教育教学改革研究与实践项目(编号:YJG20181012810)联合资助。

摘　　要：红旗营子杂岩主要块体包括太古代火成岩(斜长角闪片麻岩、石英闪长岩英云闪长岩花岗闪长岩),晚古元古代或古生代变基性岩(退变榴辉岩和斜长角闪岩),晚古生代变表壳岩(石榴角闪黑云斜长片麻岩和蛇纹石化大理岩)。本次研究的变基性岩(石榴斜长角闪岩)角闪岩相变质作用发生的时间为322.0 Ma—317.3 Ma,其围岩变表壳岩(石榴角闪黑云斜长片麻岩)沉积作用发生的时限可能为357 Ma—350.9 Ma,发生角闪岩相变质作用的时间为350.9 Ma—343.5 Ma。对红旗营子杂岩已报道的变质年龄进行汇总研究表明,存在显著的3个变质年龄区间:晚太古代2494 Ma—2448 Ma;晚古元古代1900 Ma—1734 Ma(峰期为1824.6 Ma)和显生宙495 Ma—234 Ma(峰期为323.7 Ma)。其中,晚古元古代变质年龄和显生宙变质年龄的峰值最为显著,晚古元古代变质事件可能与华北克拉通东西陆块的相互碰撞及哥伦比亚超大陆的形成有关;显生宙变质事件,可能与古亚洲洋的开裂、俯冲、关闭及造山后的伸展有关。Hongqiyingzi complex is mainly composed of Archean igneous rock(Plagioclase gneiss quartz diorite,quartz mica diorite and granodiorite),Late paleo-Proterozoic or Paleozoic meta basic rock(retrograde eclogite and Plagioclase hornblendite),and Late Paleozoic supracrustal rock(garnet hornblende biotite plagioclase gneiss and serpentinized marble).Metamorphic age of amphibolitic facies of the metabasic rock(garnet Plagioclase hornblendite)dealt with in this paper is 322.0 Ma-317.3 Ma;sedimentation age of the surrounding rock of meta-supracrustal rock(garnet hornblende biotite plagioclase gneiss)may be 357 Ma-350.9 Ma and its metamorphic age of the amphibolitic facies is 350.9 Ma-343.5 Ma.Summary of the reported metamorphic age data of the Hongqiyingzi complex show that Late Archean metamorphic age data is 2494 Ma-2448 Ma,Late paleo-proterozoic 1900 Ma-1734 Ma(peak value 1824.6 Ma)and Phanerozoic 495 Ma-234 Ma(peak value 323.7 Ma).The former metamorphic event may be related to the collision of the east and west blocks of the North China craton and the formation of the Columbia supercontinent;the latter may related to the opening,subduction,closure and post orogenic extension of the Paleo-Asian Ocean.

关 键 词：锆石U-PB年代学 石榴斜长角闪岩 (石榴角闪)黑云斜长片麻岩 红旗营子杂岩 镇宁堡—赤城地区 冀北 

分 类 号：P597.1[天文地球—地球化学]