The surface sediments, i.e. the predominant sediment type of the upper ~ 50 cm of the seabed, form the uppermost part of a sediment sequence covering the rocks of the Barents Sea. This sediment sequence varying in thickness from a few to several hundred meters and was mainly deposited during the Quaternary (the last 2.6 million years), a time period where glaciations took place repeatedly.
Mud (clay and silt) – soft bottom sedimentsDuring the last deglaciation (15 000-10 000 years ago), meltwater rivers carried large amounts of clay and silt to the ocean. Some of this was preserved in the deeper troughs on the continental shelf. However, subsequent lowering of sea level and strong bottom currents resulted in winnowing of finer grain-sizes (clay and silt) from the bank areas, and deposition of these sediments in the deeper parts. This characterizes much of the Bjørnøyrenna, Storfjordrenna and the deeper basins in the north and east of the Barents Sea.