The tectonic development of a Neogene basin at the leading edge of the active European margin: the Heraklion basin, Crete, Greece

Abstract

The Heraklion basin is located in central Crete between the Psiloritis and Dicti mountains as a graben structure, developed through Neogene and Quaternary times. Several differently oriented sub-basins, bounded by normal faults occur within the main basin. Climatic conditions and lack of vegetation expose well-preserved outcrops of the filling sediments and the fault planes, which were classified in three fault generations. Cross-cutting relationships between different faults, sub-basin’s succession, morphotectonic features and overprinting criteria between faults and sediments were used for this classification. The average-regional and local stress fields responsible for fault development were determined using slip indicators preserved on the fault planes. The tectonic and kinematic development of the Heraklion basin was governed by the relative plate behavior and the resultant geodynamic conditions at the European margin. The beginning, in the Middle/Late Miocene, of the southward roll-back of the African plate resulted in a N–S directed extension on the upper crust, that formed the first E–W trending basins of Crete. In the late Messinian, the activation of the North Anatolian fault and the associated southwestwards extrusion of the Anatolian plate accelerated an arc-parallel extension, which formed the N–S trending Heraklion, and smaller basins. Since the middle Pliocene, fault development resumed in two normal directions, NW–SE and NE–SW, as a result of a pure multi-directional extension, induced by the African plate subduction and roll-back that favors an arc-normal extension and the Anatolian extrusion, that supports an arc-parallel stretching. Active faulting in Crete supports this scenario for the present day tectonic situation.