The great heaps of unconsolidated sediment at the base of the continental slope are known as continental rise.

Here's a breakdown:

* Continental slope: The relatively steep slope that descends from the continental shelf to the deep ocean floor.

* Continental rise: A gently sloping apron of sediment accumulated at the base of the continental slope. This sediment is transported by turbidity currents, which are dense flows of sediment-laden water.

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