Evidence For Topography- And Current-Controlled Deposition On The Reykjanes Ridge Between 59 Degrees N And 60 Degrees N

Sediment patterns derived from sediment sampling and acoustic subbottom profiling were mapped on the Reykjanes Ridge (North Atlantic) between 59 degrees N and 60 degrees N. Five discrete sediment echo patterns were distinguished and mapped on a regional scale. The prolonged and layered echo facies, which mainly reflect sediment filled basins on the ridge flanks, indicate deposition of predominantly fine-grained sediments deposited by the Iceland-Scotland Overflow Water. A combination of westward flowing currents spilling over the ridge crest due to the Coriolis force together with the existing morphology probably caused the NS trending facies distribution pattern on the northwest flank.Furthermore, the modem surface sediment distribution is controlled by biological productivity, which is closely related to the mixing zone of cold subpolar surface water masses and the warm North Atlantic Current, and bottom water transport processes. The effect of bottom current transport is reflected in the pattern of settling velocity and sediment grain size. The clay mineral composition indicates that most of the fine-grained material is supplied predominantly from the Icelandic province by the Iceland-Scotland Overflow Water. Erosional processes are concentrated on narrow zones on top of the axial ridges and on the steep flanks of the Catalonia Seamount. Well-sorted foraminiferal sands on these exposed regions are assumed to represent residual sediments. Copyright (C) 1996 Elsevier Science Ltd