SEISMIC DATA ON THE STRUCTURE OF THE SEDIMENTARY COVER IN THE CRETAN TROUGH

Abstract

The southern, deep-water part of the Aegean Sea includes the Cretan Trough, which is bounded in the north by the South Aegean volcanic belt (with the well known Santorin volcano) and in the south by the Hellenic Island Arc associated with the Hellenic Trough still further to the south. One characteristic feature of the arc is the seismofocal Benioff layer that dips to the north and under the Cretan Trough at an angle of 30°C, away from the Hellenic Trench. Data on the plutonic structure of the crust and the deep-water drilling data from the Cretan Trench, in conjunction with CSP results, suggest the following explanation of the plate tectonics of the area. The Cretan Trough seems to have originated and evolved by emplacement during pre-Miocene times as a consequence of a splitting of the continental crust and the onset of crustal extension. During the Early Miocene, rift structures were formed and evaporite deposits accumulated within them. Subsidence began at the end of the Miocene and in the Early Pliocene, with the through stabilizing to a state similar to that observed now by the beginning of the Quaternary. After this, the sediments of the Quaternary complex were deposited.