Unconsolidated marine sediments in Baffin Bay

ABSTRACT Sediment in Baffin Bay is predominantly mud, with minor amounts of sand and gravel. Median grain sizes are generally related to bottom topography, being coarsest over topographic highs and finer in the central basin. Slight variations in median grain size of mud deposits in the central basin occur in a pattern that coincides with the boundary of the Baffin Land Current, which suggests that this current is capable of transporting courser sediment than adjacent water masses. Scattered pebbles and grains of coarse sand reflect the continuous influence of ice-rafting in the area. Sediment texture is generally slightly coarser with depth below the bottom, indicating a decrease in current competence with time. Such a decrease is in accord with the idea of a post-glacial general rise in relative sea level in the Arctic which is indicated from other lines of evidence. Beds of sandy sediment occur in several cores taken from the deepest part of Baffin Bay. Some of this sand is terrigenous, and is arkosic in composition. It was transported to its present deep-sea sites by downslope- moving bottom currents or suspended-flow phenomena. Much of the sand is composed of mud aggregates, however, and it appears on the basis of sedimentary structures that the beds containing these features were deposited as "fluxoturbidites" or submarine slumps.