Mass movements in glaciomarine sediments on the Barents Sea continental slope

The Pliocene and Pleistocene sediments in the Bear Island Trough and continental slope of the western Barents Sea constitute a large depositional wedge. This wedge, believed to consist of glaciomarine sediments, is divided into two major sediment packages, separated by the upper regional unconformity (URU). On the shelf, this boundary is observed as a distinct angular unconformity between older, prograding sediments and an upper, horizontally layered unit. On the outer shelf and continental slope, the upper regional unconformity represents the transition between heavily disturbed sediments below, and less disturbed sediments above. We propose that almost all of the glaciomarine sediment units below the upper regional unconformity on the continental slope have been subject to various degrees of mass movements. These features occur as a complex of large sheet and rotational slope failures covering a total area of approximately 25,000 km(2). The mass movements occurred only over short distances and took place in at least five separate events. The distinct contrast in the seismic character below and above the upper regional unconformity is a result of a change in the amount of sediment input which may correlate with the frequency of glacial advances and their erosional capacity at different times.