Sediment transport mechanisms from the slopes and canyons to the deep basins south of Crete Island (southeast Mediterranean)
Sediment transport processes from the slopes to the deep basins were studied in the southern Cretan margin (Eastern Mediterranean) by means of swath bathymetry, seismic reflection (airgun) profiling, and gravity coring. Mud/silt turbidites, developed in structureless or laminated patterns, appear to dominate the continental slope and the 2700–3600-m deep depressions of Samaria, Messara, and Gortys. These deposits are the result of successive mass transport events and turbidity currents. Over-steepening caused by strike–slip shearing associated with extensional tectonic activity in the shallow crustal levels, shaking due to significant seismic activity, and the presence of weak sediment layers are responsible for frequent triggering of slope failures and the subsequent formation of turbidity currents on the Gavdos slope. On the Cretan slope, sediments channeled as turbidity currents through canyons proved to be the major delivery mechanism, together with debris flows. Subordinate contributions of hemipelagic sediments occur only in the Messara basin. Moreover, steep non-incised slope areas and slope-confined canyons of the Gavdos slope were found to provide comparable sediment contribution with the fluvially connected canyons of the Cretan slope.
The bathymetric and seismic-reflection data as well as the sediment cores presented in this paper were acquired in the context of the HERMES Project (GOCE-CT-2005-511234-1). We greatly appreciate the constructive reviews of Dr. Flemming and Dr. Delafontaine for reviewing an earlier version of this manuscript. Moreover, the authors acknowledge the constructive reviews provided by Dr. Á. Puga-Bernabéu and an anonymous reviewer, as well as the valuable contribution of the editor Prof. Andrew Green in the finalizing of the manuscript.
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Conflict of interest
The authors declare that they have no conflict of interest.
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