DAMUTH, JOHN E., University of Texas at Arlington,Arlington,Texas; HILARY C. OLSON, University of Texas Institute for Geophysics,Austin,Texas; MARTYN S. STOKER, British Geological Survey, Edinburgh, UK

Abstract: Neogene-Quaternary Depositional Processes on the West Shetland Slope and Faeroe-Shetland Channel Revealed by High-Resolution Seismic Facies Analysis

The Neogene and Quaternary sediments of the Faeroe-Shetland Channel and West Shetland slope have been deposited and modified through complex interaction of a variety of downslope and parallel-to-slope depositional processes. Active industry exploration on the slope requires an understanding of these processes for hazards evaluation and engineering purposes.The upper slope is dominated by mass-transport deposits, which were apparently deposited during glacial cycles when ice sheets reached the shelf edge and supplied large amounts of terrigenous sediment to the slope. Thin, prograding clinoforms separate packages of debris flows and may represent glacial marine sedimentation during periods of ice retreat (e.g. interstades).The middle to lower slope has apparently been dominated by contour-current deposition since late Oligocene. Large migrating sediment waves or drifts indicate that strong contour currents have interacted with the downslope processes and redistributed sediments along the slope.A few submarine canyons occur on the upper slope and probably provide conduits to the basin for turbidity currents and related mass flows, which followed channel-like pathways along the troughs of the sediment waves to the basin.The basin floor has thin conformable sediments that appear to be predominantly glacial marine and hemipelagic with thin intervals of interbedded turbidites and debris flows. In addition, very thick (>100 m), regionally extensive mass-transport deposits also occur beneath the basin floor in the northeastern part of the area (e.g. Miller Slide).

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England