Oceanography and submarine sediment distribution in the Marmaris – Ka region of southwest Turkey

We present new oceanographic and modern sediment distribution data for transects along Marmaris-Fethiye- Kalkan-Ka-Finike and Antalya Bays (southwestern Turkey). Water temperature, salinity and dissolved oxygen content were measured and mapped for this region. Furthermore, we made short-term current speed measurements at the surface, 20m depth and the sea floor and use this data to interpret sediment movement. Orange peel and other types of grabs were used for surface sediment sampling. Samples were processed with Standard Methods of grain size analysis. Our regional maps of sediment distribution reflect grain size on a 1:100.000 scale. We used correlations between all our grain size data in our maps. Sediment distribution in this region is affected by current systems, bathymetry and both submarine, and terrestrial topographic features of the region. Finer materials do not accumulate in regions with high wave and current energy. Thus we find mostly thin accumulations of coarse material in our study region. Either sediment does not accumulate at all along continental slopes exceeding 10 degrees or very little sediment accumulates there. Sediments in our study area consist of five types of basic sedimentary material: rock, gravel, sand, silt, clay and mud. Gravelly materials are gravel, sandy gravel and muddy sandy gravel. Sandy materials are sand, gravelly sand, gravelly muddy sand, muddy sand, silty sand and clayey sand. Silty material is composed of silt and sandy silt. Muddy materials consist of mud, gravelly mud and gravelly sandy mud. Deep parts of the area contain as well as mud which is high ratio clay. Generally, grain size distribution in this region is transitional from coarse to fine and trends parallel to the coastline. Generally, gravel and sandy gravel material are found in shallow areas and reach thickness of up to 5 meters. Blocks of limestone occur on the seafloor along coasts with steep seaward slopes. Gravel size materials are uncommon. Sandy materials accumulate at approximately 20-50-100-200 meters water depth. Silty materials are deposited at 200-500-750, 500-1200 meters depth at the sea floor. Muddy materials, however, are not found until 1200-2500 meters water depth and clayey materials spread further out to below 2500 meters depth.