Numerous mounds are found aligned in a SW-trending chain on the floor of the central Barents Sea and are interpreted as glacial rafts. Glacitectonic megablocks and rafts occur widely in glaciated lowlands, as shown by many terrestrial examples of flat-topped allogenic pieces of sedimentary rock or till (Ringberg et al. 1984; Ruszczyńska-Szenajch 1987; Aber 1988). In the Barents Sea, Cenozoic–Mesozoic subcropping sedimentary bedrock appears particularly susceptible to glacitectonic deformation and erosion, as shown by the occurrence of megablocks and rafts within Pleistocene glacial sediments (Sættem 1994; Andreassen et al. 2004). Terrestrial and marine examples both show that megablocks and rafts tend to be found within till rather than at its surface and such features are, therefore, rare as seafloor landforms.
Description
About 1300 flat-topped mounds are present on the seafloor in the Bear Island Trough in the central Barents Sea, at water depths of c. 350 m (Fig. 1). The most pronounced mounds, with heights up to 28 m above the surrounding seafloor, occur aligned in a chain extending for at least 50 km. Mounds tend to be elongate with their preferred orientation varying across the area. Overall, the chain of mounds trends NE–SW, roughly parallel to …
