华北北部古生代-中生代多期变质作用及其大地构造意义——“华北地区古生代变质作用和动力学”研究进展与展望  

Multiple phases of metamorphism during Paleozoic-Mesozoic and the implication for the tectonic evolution of northern North China:Research progresses and Prospects of"The Paleozoic metamorphism and tectonic dynamics in North China"

作　　者：初航[1,4] 张晋瑞 魏春景 王惠初[1,4] 康健丽[1,4] CHU Hang;ZHANG Jin-Rui;WEI Chun-Jing;WANG Hui-chu;KANG Jian-li(Tianjin Institute of Geology and Mineral Resources,Tianjin 300170,China;College of Earth Sciences,Jilin University,Changchun 130061,China;School of Earth and Space Sciences,Peking University,Beijing 100871,China;North China Center for Geoscience Innovation,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,300170 [2]吉林大学地球科学学院,长春130061 [3]北京大学地球与空间科学学院,北京100871 [4]中国地质调查局华北地质科技创新中心,天津300170

出　　处：《地质调查与研究》2020年第2期186-197,共12页Geological Survey and Research

基　　金：中国地质调查局项目(1212011121077,DD20190075);国家自然科学基金(青年基金编号:41702049,面上项目编号:41572046)。

摘　　要：“华北地区古生代变质作用和动力学”是2011—2013年中国地质调查局地质调查工作项目,旨在通过变质作用研究,揭示古生代区域大地构造体制与演化过程。通过对河北赤城地区红旗营子杂岩、内蒙古中部温都尔庙群、宝音图群、锡林郭勒杂岩、林西地区的双井片岩等开展了重点研究,表明华北北部地区古生代以来经历了4期不同性质的变质作用,对应不同的构造背景:志留纪的高压低温型(454~426 Ma),指示洋壳的俯冲过程;早泥盆纪的中压型(~400 Ma),指示与地壳加厚有关的造山过程;石炭纪的低压高温型(345~309 Ma),指示造山后的陆内伸展过程,以及早三叠纪(~240 Ma)的中-低压低温型,指示与有限海盆闭合有关的陆内造山过程。结合区域的岩浆、沉积以及构造等方面的地质特征,认为华北北部地区古生代以来经历了复合造山的构造演化过程:早古生代期间的古亚洲洋俯冲;早泥盆纪与古亚洲洋闭合有关的碰撞造山;中-晚泥盆纪-二叠纪陆内伸展,形成陆相盆地-陆表海-有限海盆;以及早三叠纪的有限洋盆被动闭合等过程。这为阐明华北地区古生代地球动力学和成矿背景提供了坚实的变质岩石学基础。‘The Paleozoic metamorphism and tectonic dynamics in North China’is the 2011—2013 Geological survey work project of China Geological Survey,which aimed to reveal the tectonic regime and evolutional history of the northern part of North China through the study of metamorphism.Comprehensive investigations were carried out on the metamorphic evolution including the Hongqiyingzi Complex at the Chicheng area,Hebei province,and the Ondor Sum Group,Baoyintu Group,Xilingol Cmplex as well as the Shuangjing Schist from the central Inner Mongolia.Four phases of metamorphism can be identified,including:(i)the Silurian(454~426 Ma)high P/T metamorphism;(ii)the Early Devonian(~400 Ma)medium P/T metamorphism;(iii)the Carboniferous(345~309 Ma)high temperature-low pressure metamorphism;and(iv)the Early Triassic(~240 Ma)low temperature and medium-low pressure metamorphism.Associated with previous studies on other geological issues,the tectonic evolution since the Paleozoic in the northern part of North China involves:(i)the Early Paleozoic Paleo-Asia Ocean subduction;(ⅱ)the Early Devonian collisional orogeny due to closure of the Paleo-Asian-Ocean;(ⅲ)the within-plate extension from late Devonian to Permian resulting in the development of continental,epicontinental sea and limited sea basins;and(ⅳ)the passive closure of limited sea basins after Early Triassic.These results have provided a robust basis for settling the Paleozoic geodynamics and metallogenic background in North China.

关 键 词：多期变质作用 古生代-中生代 大地构造 兴蒙造山带 华北北部 

分 类 号：P534.4[天文地球—古生物学与地层学] P588.34[天文地球—地质学]