Intracontinental wedging and post-orogenic collapse in the mesohellenic trough

The Mesohellenic Trough is a 130 km long and about 30 km wide subsiding area which contains a thick sequence of well exposed Late Cenozoic post-orogenic sediments. This intermontane basin, located at the contact between the Apulian and Pelagonian collided margins, provides a good example of the characteristics needed to study the chronology of late orogenic intracontinental structures.The Mesohellenic Trough was developed from the Middle Eocene to Middle Miocene as a piggy-back basin along the eastern flanks of a giant pop-up structure. This structure consists of west-verging, foreland-propagating thrusts within the Apulian plate and of east-verging backthrusts within the Pelagonian plate. As a result the eastern parts of the Apulian margin were thickened and uplifted, followed by post-orogenic collapse.Internal deformation of the sedimentary infill varies widely along the trough axis. At the northern and southern terminations of the trough, two small indentors induced a tectonic escape towards the central part of the basin until the Middle Miocene. During this process of convergent wrenching, reverse strike-slip faults and pure strike-slip faults formed. Towards the central part of the trough, convergent wrenching decreased gradually until it was replaced by a post-orogenic collapse with normal and oblique normal faults trending parallel and/or perpendicular to the trough axis.