SEDIMENT DEPOSITION IN AN ICEBERG-DOMINATED GLACIMARINE ENVIRONMENT, EAST GREENLAND - BASIN FILL IMPLICATIONS

Kangerdlugssuaq Fjord, east Greenland (68 degrees N), is an iceberg do minated fjord, receiving in excess of 15 km(3)/a in iceberg volume, re presenting about a thousand fairly-large icebergs each year. In contra st, the estimated combined flux of subglacial and supraglacially deriv ed meltwaters is of the order of 4 km(3)/a. Iceberg melt within the fj ord accounts for half of the freshwater delivered to the fjord from al l sources. Icebergs appear to lose their subglacial debris during thei r lengthy residence time (2 year) within the sikussaks pinned to the i ce margins. Once icebergs escape the confines of the sikussaks, they t ransit the fjord in about 68 days, melting at rates between 0.05 and 0 .1 m/d and releasing englacial sediment to a mid-water, iceberg melt z one. Sedimentation beneath this plume is predicted to range from 2.4 c m/a, near the head of the fjord, to 0.6 cm/a at the most distal (50 km ) part of the fjord basin. Much of the sediment that initially accumul ates on the steep sidewall margins becomes remobilized and redeposited on the distal basin floor via turbidity currents. Predicted accumulat ion rates agree with long-term (1400 year) rates obtained from dated c ores collected in Kangerdlugssuaq Fjord.