Figure 6. Schematic drawing of the processes active during glacial half-cycles, leading to the development of hemipelagic sediment drifts on the continental rise (adapted from Rebesco et al., 1997). The unstable component of unsorted upper-slope deposits forms first debris flows, then turbidity currents. The fine fraction is suspended and entrained in ambient bottom currents to be deposited downcurrent. Drifts are built above the level of the dendritic pattern of turbidity current channels because (in the case of the Antarctic Peninsula margin and perhaps elsewhere) subsequent turbidity currents erode the deposited sediment everywhere except upon the drifts and maintain the steeper drift slopes at the limit of stability.

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