Abstract
Terra Nova, 23, 270–279, 2011 Abstract The Ammarnäs Complex is a tectonic unit in the Middle Allochthon of the central Scandinavian Caledonides and consists of several hundred metres of thick uniform meta-greywacke successions of greenschist metamorphic grade containing kilometre-scale lenses of pre-Caledonian crystalline basement rocks. Meta-greywacke samples were analysed for major and trace elements and U-Pb isotopes. Lithoclasts and geochemical data indicate that the greywackes were derived from granitic–granodioritic rocks. Detrital zircon dating yielded 7% Neoproterozoic, 52% Mesoproterozoic and 41% Palaeoproterozoic 207Pb/206Pb ages with two prominent age peaks at 1.64 and 1.5 Ga and a broad distribution of Sveconorwegian (1140–900 Ma) and ‘pre-Sveconorwegian’ (1340–1140 Ma) ages. We interpret the Ammarnäs Complex as a former Neoproterozoic basin in the foreland of the Sveconorwegian orogen, which escaped major pre-Caledonian magmatism–metamorphism and which was most likely deposited between c. 920 and 630 Ma. Terra Nova, 00, 1–10, 2011
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
