Lithodynamic studies near the Northwest Atlantic Mid-ocean channel

In AMK-4474 marine sediment core, recovered from the northern part of the eastern (left) levee of the Northwest Atlantic Mid-Ocean Channel, two stratigraphic units were identified. The lower unit is represented by the Late Quaternary fine-grained sediments of the upper turbidite sequences. The presence of a 17–24 µm mode in grain-size distributions within the thin silt interlayers in the lower unit may reflect a sorting process of sedimentary material by the spillover of turbidity currents which is similar to the contour currents activity. This allows applying an indicator of the contour current speed — sortable silt (SS) content — to estimate the intensity of the spill-over current. The upper unit, formed during the last 26 ka, is represented by pelagic sediments. The presence of the fine-grained interlayer in the upper unit of AMK-4474 core is apparently due to a decrease in IRD supply to the study area.