华北克拉通南缘下地壳麻粒岩地体的形成与演化  

Formation and evolution of lower crustal granulite terranein the southern North China Craton

作　　者：王景丽 张宏福 WANG JingLi;ZHANG HongFu(School of Petroleum Engineering and Environmental Engineering,Yan an University,Yan an 716000,China;School of Earth Sciences,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]延安大学石油工程与环境工程学院,延安716000 [2]浙江大学地球科学学院,杭州310058

出　　处：《岩石学报》2022年第12期3819-3834,共16页Acta Petrologica Sinica

基　　金：国家自然科学青年基金项目(41803035);延安大学博士科研启动项目联合资助.

摘　　要：研究前寒武纪地体的构造-岩浆事件和变质作用过程是揭示早期陆壳的生长与演化等热点问题的重要途径。目前,尽管已经开展了大量的相关研究,但关于华北克拉通南缘前寒武纪变质地体的成因、构造背景仍存在争议,限定了我们对于华北克拉通南缘前寒武纪形成和演化的认识。本文根据前人研究成果,包括华北南缘太华杂岩的岩相学、地球化学、年代学以及变质P-T-t轨迹等,结合对鲁山地区太华杂岩的全岩主微量、长石矿物原位Pb同位素组成特征以及基性麻粒岩的年代学等研究成果,系统梳理并探讨了太华杂岩代表的新太古代-古元古代下地壳物质组成、岩石成因以及多阶段构造-岩浆事件。结果显示华北南缘记录了2.92~2.71Ga和2.53~2.45Ga两期重要的地壳生长事件,2.35~2.30Ga和2.19~2.06Ga的陆壳再造,以及1.96~1.84Ga古元古代的变质事件。再结合华北克拉通中部造山带中、北部的变质程度、变质P-T轨迹和变质年龄,我们认为华北南缘前寒武纪基底与中部造山带的中、北部相似,构造归属于中部造山带,发生了一个较长的俯冲碰撞造山过程(1.96~1.86Ga)。Studies focused on the tectono-magmatic events and subsequent metamorphism for the Precambrian terranes are crucial for revealing the growth and evolution of early continental crust.Although many studies have been conducted,the petrogenesis and the corresponding tectonic settings for the Precambrian metamorphic rocks in the southern margin of North China Craton(NCC)are still debated,which has limited our understanding on the formation and evolution of the NCC.In this contribution,data from our published and forthcoming research results on the whole rock trace element,in-situ zircon Pb isotope and geochronology analyses of the Taihua complex in Lushan area were synthetically analyzed,combined with previous studies including the petrography,geochemistry,geochronology and metamorphic P-T-t path,with the aim to elaborate the composition,petrogenesis and multi-stage tectono-thermal events for the Neoarchean and Paleoproterozoic crust in the southern margin of NCC.The results reveal two important crustal growth events at 2.92~2.71Ga and 2.53~2.45Ga,juvenile crustal reworking and recycling at 2.35~2.30Ga and 2.19~2.06Ga,and Paleoproterozoic metamorphism at 1.96~1.84Ga.Together with reported P-T path and metamorphic geochronology in the central and northern part of Trans-North China Orogen,we inferred that the Paleoproterozoic collision between the Eastern Block and Western Block of the NCC started as early as~1.96Ga and lasted until 1.86Ga,corresponding to a long-lived tectono-metamorphic event.

关 键 词：构造-岩浆事件 太华杂岩 麻粒岩地体 大陆下地壳 华北克拉通南缘 

分 类 号：P542[天文地球—构造地质学] P588.3[天文地球—地质学]