Late Cenozoic deformation of the Gavrovo and Ionian zones in NW Peloponnesos (Western Greece)

Abstract

The structural deformation of Mesozoic-Tertiary sediments of the Ionian and Gavrovo zones in NW Peloponnesos is related to the propagation of a fold-thrust system during the Cenozoic. The sediments of the Gavrovo zone have been deformed by high angle reverse faulting generating an imbricate fan. Skolis mountain represents the Gavrovo thrust front. The detachment occurred in the underlying flysch of the Ionian zone. The Ionian zone has also been affected by shortening above a detachment horizon situated in the lower horizons of Triassic evaporites. The main compressional structure of the Ionian zone is a broad anticline revealed by a seismic survey west of Skolis mountain. The Gavrovo-sheet emplacement caused the downthrow and bending of the eastern part of the Ionian zone followed by halokinesis of Triassic evaporites to the west. Post-compressional normal faulting has predominated since the Pliocene, resulting in the formation of the Kato Achaia and Simopoulo basins in the peripheral area of Skolis mountain. Diapirs of Triassic evaporites occur in the mentioned basins that complicate the tectonic pattern in front of the Skolis thrust.