Figure 6. Cartoon of processes leading to construction and maintenance of a hemipelagic drift deposit along the Antarctic Peninsula margin (from Rebesco et al, in press), showing a section through a shelf progradational lobe and adjacent continental rise during a glacial maximum when an ice sheet grounded to the shelf edge is transporting unsorted basal till to the upper slope. Small scale slumps on the uppermost slope become debris flows. Farther downslope, these become turbidity currents which flow via tributaries on the uppermost rise into the main channel running between the drifts towards the abyssal plain. Suspended fines are entrained in ambient bottom currents and deposited down-current. Subsequent turbidity-current flow in the channels, and slope instability on the steeper drift slopes sweep those recent deposits away, leaving a permanent sediment increment only on the gentle slope of the drifts.

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