Upper slope sediment waves in the Cilician Basin, northeastern Mediterranean

Abstract

Large sediment waves have been observed within the upper slope deposits of the Cilician Basin (northeastern Mediterranean), at the interfluve between two submarine canyons present offshore of the Mersin Shelf. There are several generations of sediment waves stacked within the sedimentary sequence, with the most recent bedforms found on the seabed in an area consisting of fine-grained sediments. The surficial sediment wave field, estimated to cover an area of ∼55 km2, is found at water depths between 250 and 310 m. The buried sediment wave fields have similar dimensions, but they are located further downslope. Wave dimensions increase with water depth and depth in the sedimentary sequence. The largest bedforms reach 40 m in height and 1.8 km in length. Most waves appear to have been migrating upslope, i.e. towards the north/northeast, and this migration direction is mostly consistent throughout the sedimentary sequence. This consistency indicates similar mechanisms of formation and maintenance over a considerable time interval. The morphology and migration pattern of the observed bedforms suggests that sedimentation in the Cilician Basin during wave formation has been controlled by near-bed flows resembling those generated by the present Asia Minor Current, although these flows may have been stronger in the past than they are at present.