Tertiary-Quaternary Deposits in External Hellenides; an Integrated Geophysical-Sedimentological Study in Diapontia Islands – N. Ionian Sea

The offshore area of north Corfu Island in NW Greece is lying to the external part of the Hellenides Fold and Thrust Belt, corresponding to a clastic piggy-back basin developed during the late Tertiary, due to the Ionian thrust activity. The purpose of this study is to examine the thickness, the lateral distribution, and the facies of the Tertiary-Quaternary deposits across the basin. Understanding the deposition of these sediments shedding light on the paleogeographic history and sediment facies distribution of the area.

A detailed sedimentological analysis on East-Erikoussa-1 well along with seismic interpretation on selected seismic lines, were the main tools which have been used.

The study confirmed that turbidites deposited during the Oligocene-Pliocene, due to the Ionian thrust activity. Seismic data revealed complex tectonism of the area with several thrust sheets forming the Ionian thrust, while elongated strike-slip faults, crosscut the piggy-back basin internally, forming local depocenters. Pleistocene shallow marine sedimentation is related with the subsidence of the sea and the gradual shallowing of the area. The total thickness of the Tertiary-Quaternary deposits reaches 3km locally, with favourable reservoir and sealing properties. Traps are also present, while recent studies suggest that these deposits could serve as potential source rocks.