Publication Date:
2015-01-31
Description:
The Dinarides-Hellenides result from underthrusting of the Adriatic margin during Africa-Europe convergence. In Albania, they consist of (1) a Western zone of nappes derived from Adria; (2) a Central belt made up of the Mirdita ophiolites; and (3) an Eastern zone, the Korabi-Pelagonia zone, of Variscan basement overlain by Permian to Mesozoic rift deposits and carbonates. Some authors interpret the Korabi-Pelagonia zone as a micro-continent between the Mirdita–Pindos oceanic basin to the west and the eastern Vardar oceanic basin to the east, other regard the Korabi-Pelagonia zone as a tectonic window below a single ophiolitic nappe. This contribution argues for a far-travelled thrust sheet. The Mirdita ophiolites is 165-160 Ma. The metamorphic sole yielded 40 Ar/ 39 Ar ages of 171 to 162 Ma. The Korabi-Pelagonia zone is subdivided into the Korabi and Gjegjan subzones. The structural analysis of these rocks supports the rooting of the Mirdita ophiolites in the Western Vardar zone. The post-Variscan cover sequence of the Korabi subzone records two phases of deformation: D 1 is associated with a SE-dipping to flat-lying schistosity axial-planar to NW-verging folds and thrust faults, related to ophiolite obduction; D 2 is a post-obduction NNE-trending crenulation cleavage. Published zircon fission-tracks analyses yielded 150-125 Ma, suggesting that regional metamorphism is Early Cretaceous or older. K-Ar mica ages from correlative rocks of Macedonia cluster between 148 and 130 Ma, indicating that D 1 is Late Jurassic. A west-directed obduction is favoured, as is a rooting east of the Mirdita ophiolites because of the top-to-West structural polarity of obduction-related deformation.
Print ISSN:
0278-7407
Electronic ISSN:
1944-9194
Topics:
Geosciences
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