Reconstruction of the mid-Devonian HP-HT metamorphic event in the Bohemian Massif(European Variscan belt)  

作　　者：Stephen Collett Karel Schulmann Piérig Deiller PavlaŠtípská Vít Peresty Marc Ulrich Yingde Jiang Luc de Hoÿm de Marien Jitka Míková 

机构地区：[1]Centre for Lithospheric Research,Czech Geological Survey,Klárov 3,11821 Praha 1,Czech Republic [2]Institut Terre et Environnement de Strasbourg,UMR 7063 Universitéde Strasbourg—CNRS,1 Rue Blessig,67084 Strasbourg,Cedex,France [3]Institute of Petrology and Structural Geology,Charles University,Albertov 6,Praha 212843,Czech Republic [4]State Key Laboratory of Isotope Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China [5]Laboratories of the Czech Geological Survey,Geologická6,15200 Praha 5,Czech Republic

出　　处：《Geoscience Frontiers》2022年第3期177-195,共19页地学前缘（英文版）

基　　金：funded by the Grant Agency of the Czech Republic(GACR)project 19-25035S to P.Štípskáand the International Partnership Program of CAS 773(132744KYSB20190039)to Y.Jiang;Institutional supports of the Research Project no.310760(Strategic Research Plan of the Czech Geological Survey-DKRVO/CGS 2018-2022);Centre for Geosphere Dynamics(UNCE/SCI/006)of Faculty of Sciences,Charles University

摘　　要：Mid-Devonian high-pressure(HP)and high-temperature(HT)metamorphism represents an enigmatic early phase in the evolution of the Variscan Orogeny.Within the Bohemian Massif this metamorphism is recorded mostly in allochthonous complexes with uncertain relationship to the major tectonic units.In this regard,the MariánskéLázně Complex(MLC)is unique in its position at the base of its original upper plate(Teplá-Barrandian Zone).The MLC is composed of diverse,but predominantly mafic,magmatic-metamorphic rocks with late Ediacaran to mid-Devonian protolith ages.Mid-Devonian HP eclogite-facies metamorphism was swiftly followed by a HT granulite-facies overprint contemporaneous with the emplacement of magmatic rocks with apparent supra-subduction affinity.New Hf in zircon isotopic measurements combined with a review of whole-rock isotopic and geochemical data reveals that the magmatic protoliths of the MLC,as well as in the upper plate Teplá-Barrandian Zone,developed above a relatively unaltered Neoproterozoic lithospheric mantle.They remained coupled with this lithospheric mantle throughout a geological timeframe that encompasses separate Ediacaran and Cambrian age arc magmatism,protracted early Paleozoic rifting,and the earliest phases of the Variscan Orogeny.These results are presented in the context of reconstructing the original architecture of the Variscan terranes up to and including the mid-Devonian HP-HT event.

关 键 词：Variscan Orogeny Avalonian-Cadomian Orogeny ECLOGITE Geochemistry Zircon Lu-Hf geochronology 

分 类 号：P534.44[天文地球—古生物学与地层学] P588.3[天文地球—地质学]