Alpine tectono-metamorphic history of the continental units from Vardar Zone: the Kopaonik Metamorphic Complex (Dinaric-Hellenic belt, Serbia)

Abstract

The easternmost zone of the Dinaric-Hellenic belt is represented by the Vardar Zone, in which the Kopaonik Metamorphic Complex is regarded as the lowermost unit. This complex is topped by the unmetamorphosed Brzece unit and is intruded by the Oligocene Kopaonik Intrusive Complex. The Kopaonik Metamorphic Complex is characterized by a stratigraphy that includes metapelites and meta-carbonates of Late Triassic age, associated with metabasites. It is characterized by a complex deformation history that comprises four phases: D1 to D4. The D1 phase structures occur only as relict structures, whereas the D2 phase structures are represented by isoclinal F2 folds, associated with a well developed S2 foliation. The estimated P-T conditions for the D1 and D2 metamorphism are consistent with the upper greenschist facies. The D3 phase is characterized by west-verging thrusts associated with upright folds. In contrast, the D4 phase is characterized by open folds (F4) associated with low-angle normal faults. The D1 and D2 deformation phases developed during the shortening related to continental collision, whereas the subsequent D3 and D4 phases can be related to the progressive exhumation of the Kopaonik Metamorphic Complex. The D4 phase probably developed during extensional tectonics during and after emplacement of the Kopaonik Intrusive Complex. The data show that the continental units belonging to the Vardar Zone had a long-lived deformation history that was more complex that previously thought