Tectonic evolution of the Hellenic Orogen. Geometry and kinematics of deformations

Abstract

The Hellenic orogen consists of three orogenic belts: 1) the Cimmerian orogenic belt, including Rhodopian, Serbomacedonian, Circum Rhodope, Axios and Pelagonian zones, is the internal belt which has been created in pre-Late Jurassic times as a result of the northward drift of Cimmerian contrinental fragments from Gondwana towards Eurasia. Ophiolites from small ocean basins were mainly emplaced onto the Cimmerian continental margins in Middle Jurassic. 2) the Alpine orogenic belt, including External Hellenides and Pindos-Subpelagonian ophiolites and oceanic sediments (Neo-Tethyan), which has been created in Cretaceous-Paleogene times after the subduction of the Neotethyan oceanic crust beneath the Cimmerian-Eurasian plate and the collision of the Apulian microplate to the later, 3) the Mesogean orogenic belt along the External Hellenic orogenic arc as a result of the Mesogean-African underplate beneath the unique Alpine-Cimmerian-Eurasian plate in Miocen- Pliocene times and the exhumation of the Cretan-Southern Peloponesus tectonic windows. Structural analysis and detailed studies of the geometry and kinematics suggest that during Alpine-Mesogean orogenic process a SW-ward migration of successive complessional and extensional tectonic events took place resulted of successive subductions. Thus, crustal thickening produced by compressional tectonics in each area was followed by an extensional exhumation of underplate rocks as tectonic windows.