Record details

Title
    Vestige of an Early Cambrian incipient oceanic crust incorporated in the Variscan orogen: Letovice Complex, Bohemian Massif
Author
    Janoušek, Vojtěch
    Košler, Jan
    Machek, Matěj
    Soejono, Igor
    Žáčková, Eliška
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Journal of the Geological Society London
Vol./nr.
    Roč. 167, č. 6
Pages
    18
Year
    2010
Thesaurus term
    Early-Cambrian rifting, Structural geology, Geochemistry, U-Pb dating, Gondwana margin, Variscan orogen, Bohemian Massif
Keyword
    Bohemian
    Cambrian
    Complex
    Crust
    Early
    Incipient
    Incorporated
    Letovice
    Massif
    Oceanic
    Orogen
    Variscan
    Vestige
Abstract (in english)
   The Letovice Complex, composed of E-MORB metabasalts with trondhjemite sheets, gabbroic and ultrabasic bodies, is exposed within an important Variscan suture separating the Moldanubian Domain (W) from the Brunovistulicum (E). Its polyphase tectonic evolution was connected with underthrusting and subsequent exhumation of the former oceanic realm, which resulted into three deformation phases (D1-D3). New U-Pb LA ICP-MS dating of magmatic Zrn from amphibolite and trondhjemite yielded statistically identical concordia ages of 530 ? 6 Ma and 529 ? 7 Ma, respectively. These are interpreted as dating intrusions of the Early Cambrian protoliths of the studied rocks. Based on this age as well as whole-rock geochemical and Nd isotopic data, the Letovice Complex is interpreted as a vestige of an incipient oceanic basin developing on attenuated crust. The most likely geotectonic setting was a post-Cadomian extensional regime at the northern margin of Gondwana that marked the onset of its breakup.
Contributor
    Česká geologická služba
Contributor code
    ČGS (RIV)
Source format
    R
Import date
    15. 10. 2014