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Contourites |
Lamont-Doherty Geological Observatory of Columbia University in the City of New York, Palisades, New York 10964, USA
Samples of three piston cores and one gravity core from the Nova Scotia continental rise (depths 42104925 m) have been examined to differentiate parallel-to-slope and downslope depositional processes in Quaternary deposits from a region presently influenced by a strong contour current. Measurement of anisotropy of magnetic susceptibility of samples of a red-brown, silt-laminated lutite contourite facies shows grain alignments which are consistent with both parallel-to-slope (contour current) flow and downslope (turbidity current) flow. We believe that these results provide support for the hypothesis that geologically significant contour currents have influenced continental rise deposition during the Pleistocene. However, our observation that both alongslope and downslope alignments are present in lithologically similar units clearly demonstrates the need for studies on the relationship between lithofacies and process in this geological setting.