Effects of bottom currents and fish on sedimentation in a deep- water, lacustrine environment.

Sands and muds accumulating under the influence of apparently strong bottom currents in a deep-water environment of Lake Superior were studied. Reveals lineations subparallel to the direction of bottom-current flow that are interpreted in different areas to be sand ribbons, slight depressions, or depositional furrows. The sediments range from silty sand in the scoured trough to sandy clays further offshore. The sediments are postglacial rather than relic glacial-lacustrine sediments. Grain size distributions are affected by bottom currents and a nearby source of sand. Biological activity appears to erase traces of intermittent currents. -from Authors