Vincent Wicker

Transition from Aegean back-arc extension to Corinth rifting. Miocene to Pleistocene interacting extensional regimes of the Northern Peloponnese.

Vincent Wicker¹, Mary Ford¹, Robert Gawthorpe², Haralambos Kranis³, Emmanuel Skourtsos³, Pierre Bouilhol¹, Martin Muravchik², Natacha Fabregas², Kévin Beaufumé⁴, Hugo Beldame⁵

^{1 –} University of Lorraine, CRPG-CNRS, Nancy, France; ^{2 –} University of Bergen, Norway; ^{3 –} National and Kapodistrian University of Athens, Greece; ^{4 –} Perenco, UK; ^{5 –} ENSG Nancy, University of Lorraine, France

Continental extension is characterized by two end members: rifting and highly extended terrains. These two modes of extension usually develop under very different conditions and are rarely observed together. However, in the northern Peloponnese, metamorphic windows recording Miocene late orogenic to back arc extension of the Southern Hellenides on low angle detachments, lie directly south of the younger Pliocene-Pleistocene Corinth rift and appear to interact with its southern margin fault system. This work integrates data from a recent structural and stratigraphic field campaign from the Central Peloponnese to the Corinth rift southern margin with regional cross-sections to document the style of regional Miocene to Pliocene extensional tectonics and the transition from the wide extensional regime to the narrow Corinth rifting. It shows that the pre-rift Hellenides nappe stack was stretched by about 15-25 km by low angle extensional faults that root into the Cretan detachment that forms the main decoupling level in this area. These low-angle extensional faults contribute to the exhumation of the Quartzite-Phyllite metamorphic nappe and contribute to the continental unroofing of the Southern Hellenides. New field data in the northern Peloponnese indicate that  continental sedimentation controlled by these low angle normal faults underlies in apparent continuity the  Corinth syn-rift succession, which  is itself controlled by later high angle rift faults. We integrate in a regional structural model the transition from the pre-rift Aegean extensional tectonic regime to early-stage Corinth rifting recorded in newly mapped depocenters located in the south-eastern Corinth basin between Stymfalia and Nemea.