Gravel fraction on the Spitsbergen Bank, NW Barents Shelf.

Abstract

The gravel fraction of the bottom sediment on the Spitsbergen Bank, located south of Svalbard in the NW Barents Sea, is composed predominantly of clastic sedimentary rocks, especially sandstone and shale. Betwwen sampling stations the proportion of eight lithologic types is markedly different, ruling out the possibility of large-scale transport of the gravel by ice-rafting. Striated pebbles occur in small numbers: a few are exotic in composition, but most are similar to a non-striated rock-type at a given station. This suggests that the gravel was formed by reworking of previously glacial material, which tends to be locally derived. The sandstone pebbles in the gravel include a variety of petrographic types, most of which are identical or similar to sandstones of known stratigraphic position on Svalbard. Obervations on Mesozoic rocks of Bjørnøya, Hopen and northern Spitsbergen, and on the distribution of pebbles as described heren, suggest that the Spitsbergen Bank is underlain by nearly flat-lying Mesozoic sedimentary rocks similar to those known on Svalbard. The overall strucutre is a gentle syncline; a southward continuation of the dominant regional structure of Spitsbergen.