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| Titel |
Evidence for hyper - extension in the Pre-Caledonian continental margin of Baltica |
| VerfasserIn |
T. B. Andersen, F. Corfu, L. Labrousse, P. T. Osmundsen |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060060
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| Zusammenfassung |
| Solitary mantle peridotite, associated detrital serpentinites, minor metabasalts and gabbros as
well as deep basin sediments are inter-layered and imbricated with allochthonous
coarse-grained siliclastic metasediments and slivers of Proterozoic basement below the large
Middle Allochthon crystalline nappes in the southwest Scandinavian Caledonides. The
siliclastic sediments have provenance in Proterozoic rocks similar to those found in the
large crystalline nappes and in the autochthonous basement of Baltica. We suggest
that this mantle-peridotite bearing mélange unit, which has been mapped for more
than 400 km in southern Norway, represents vestiges of deep basin(s) formed by
hyper-extension of Baltica during the inception of the Caledonian Wilson cycle. Regional
maps show that the mélange continues into the central Scandinavian Caledonides
and that this basin assemblage therefore may have had a much large geographical
distribution. We suggest that this unit represents an ancient Palaeozoic analogue
similar to the hyper-extended Tethyan margin complexes recently described from the
Alps, the Pyrenees and from several segments of the present-day passive ocean
margins. The new model suggests that major re-interpretation of the Lower and Middle
Allochthons of the tectono-stratigraphy in the Scandinavian Caledonides is required. |
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