• Login
     
    View Item 
    •   ORFEO Home
    • Royal Museum for Central Africa
    • RMCA publications
    • View Item
    •   ORFEO Home
    • Royal Museum for Central Africa
    • RMCA publications
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    The Cambrian to Devonian odyssey of the Brabant Massif within Avalonia: A review with new zircon ages, geochemistry, Sm-Nd isotopes, stratigraphy and palaeogeography

    Thumbnail
    View/Open
    Published (5.600Mb)
    Authors
    Linnemann, U.
    Herbosch, A.
    Liégeois, J.P.
    Pin, C.
    Gärtner, A.
    Hofmann, M.
    Show allShow less
    Discipline
    Earth and related Environmental sciences
    Subject
    Geodynamics and mineral resources
    Audience
    Scientific
    Date
    2012
    Publisher
    Elsevier
    Metadata
    Show full item record
    Description
    This study provides an up-to-date and comprehensive review of the Early Palaeozoic evolution of the Brabant Massif belonging to the Anglo-Brabant Deformation Belt. Situated at the southeastern side of Avalonia microplate, it is the only well-known part of the northern passive margin of the Rheic Ocean. The Cambrian Silurian sedimentary pile is >13 km thick,with >9 km for the Cambrian only. The unraveling of this continuous registration re!ects the successive rifting and drifting of Avalonia from the Gondwana mainland, followed by soft-collisional processes with Baltica and "nally the formation of Laurussia. Based on recently established detailed stratigraphy, sedimentology and basin development, on U Pb LA-ICP-MS analyses of igneous and detrital zircon grains along with geochemical data including Sm Nd isotopes, a new geodynamic and palaeogeographic evolution is proposed. Brabant Megasequence 1 (lower Cambrian to lowermost Ordovician,>9 km thick) represents an embayment of the peri-Gondwanan rift from which the Rheic Ocean has evolved. Detrital zircon ages demonstrate that the Brabant is a typical peri-Gondwanan terrane with a major Pan-African (Neoproterozoic age) and a mixed West African and Amazonian source (Palaeoproterozoic, Archaean and some Mesoproterozoic age). The transition towards the Avalonia drifting is marked by an unconformity and a short volcanic episode. The northward drift of Avalonia towards Baltica is recorded by the Megasequence 2 (Middle to Upper Ordovician, 1.3 km thick). The source for Mesoproterozoic zircons vanished, as the result of the Rheic Ocean opening and the isolation from Amazonian sources. The transition to Megasequence 3 is marked by a drastic change in palaeobathymetry and an important (sub)volcanic episode during a tectonic instability period (460 430 Ma), re!ecting the Avalonia Baltica soft docking as also shown by the reappearance of Mesoproterozoic detrital zircons, typical of Baltica. Unradiogenic Nd isotope signature (epsNd −4/−5) and TDM model ages (1.3 1.7 Ga) for Brabant magmatic rocks indicate an old recycled component. Megasequence 3 (uppermost Ordovician to lowermost Devonian; >3.5 km thick) includes the onset of a Silurian foreland basin that re!ects the tectonic inversion of the core of the massif (Brabantian orogeny) in response to the Baltica Avalonia Laurentia collision. Finally, the comparison with the strikingly similar Cambrian successions of the Harlech Dome (Wales, Avalonia) and theMeguma terrane (Nova Scotia, peri-Gondwana) allows the construction of a new Early Cambrian palaeogeographic model for the whole Avalonia microplate, in which the Meguma terrane is included.
    Citation
    Linnemann, U.; Herbosch, A.; Liégeois, J.P.; Pin, C.; Gärtner, A.; Hofmann, M. (2012). The Cambrian to Devonian odyssey of the Brabant Massif within Avalonia: A review with new zircon ages, geochemistry, Sm-Nd isotopes, stratigraphy and palaeogeography. , Earth Science Reviews, Vol. 112, 126-154, Elsevier, DOI: http://dx.doi.org/10.1016/j.earscirev.2012.02.007.
    Identifiers
    uri: https://orfeo.belnet.be/handle/internal/1397
    doi: http://dx.doi.org/10.1016/j.earscirev.2012.02.007
    url: http://dx.doi.org/10.1016/j.earscirev.2012.02.007
    Type
    Article
    Peer-Review
    Yes
    Language
    eng
    Links
    NewsHelpdeskBELSPO OA Policy

    Browse

    All of ORFEOCommunities & CollectionsBy Issue DateAuthorsTitlesDisciplinesThis CollectionBy Issue DateAuthorsTitlesDisciplines
     

    DSpace software copyright © 2002-2016  DuraSpace
    Send Feedback | Cookie Information
    Theme by 
    Atmire NV