CRUSTAL UPLIFT AND CENOZOIC EXTENSIONAL TECTONICS OF PELAGONIA IN NORTHERN GREECE

In this study we have investigated the crustal uplift and exhumation of Pelagonia, a NNW–trending ribbon continent with Gondwana affinity in west-central Greece. The Pelagonian microcontinent constitutes the westernmost segment of the Internal Hellenide mountain belt, and its crystalline basement consists mainly of granites, gneisses, and metavolcanic rocks that range in age from late Proterozoic to Permo–Carboniferous. Triassic–Jurassic platform carbonates with hemipelagic sedimentary rocks and alkaline lavas–dikes rest on these basement rocks and represent passive continental margin units. Pelagonia was tectonically buried by ~165 Ma Tethyan ophiolites in the late Jurassic, and experienced ~ENE–WSW shortening as a result of ophiolite emplacement and its subsequent collision with Apulia in the late Paleocene–early Eocene. These major shortening events resulted in crustal thickening and regional metamorphism of the Pelagonian crust. Pelagonia and its orogenically–thickened crust began collapsing via ~E–W-directed extensional ductile deformation, faulting, and rapid erosion in the Oligo-Miocene, reminiscent of metamorphic core complexes. The Mesohellenic sedimentary basin west of Pelagonia includes Campanian (~80 Ma) through late Miocene (~6 Ma) clastic rocks with their erosional source in Pelagonia, displaying a complete record of its burial & exhumation history. Tectonic thinning, unroofing, and exhumation of Pelagonia continued into the Miocene & Plio–Pleistocene along high–angle normal faults and NNW–trending, transtensional oblique faults. This extensional deformation has been responsible for the formation of the Neogene sedimentary basins within the Pelagonian crust. We present the structural and geochronological data showing the mode and nature of the punctuated Cenozoic exhumation and uplift history of Pelagonia.