Continental Rise


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continental rise

[¦känt·ən¦ent·əl ′rīz]
(geology)
A transitional part of the continental margin; a gentle slope with a generally smooth surface, built up by the shedding of sediments from the continental block, and located between the continental slope and the abyssal plain.

Continental Rise

 

one of the principal elements of the continental margin; it is located between the base of the continental slope and the outer boundary of the ocean floor. (Some investigators consider the continental rise to be part of the ocean floor, drawing the boundary of the continental margin along the base of the continental slope.)

In terms of geological structure the continental rise is a deep trough filled by a thick layer of sediment at the junction of the continental and oceanic crust. The oldest deposits in the continental rise are Jurassic deposits discovered by deep-water drilling, but it is not impossible that even more ancient sediments will be found. In a geomorphological sense the continental rise is usually a rolling, sloping, accumulative plain, which formed as a result of the accumulation of sedimentary material carried down from the continental slope. The debris cones of turbidity currents, which are usually confined to the mouths of submarine canyons, are very important in the structure of the continental rise. The surface of the continental rise has hilly relief in many areas (for example, south of the island of Newfoundland). A continental rise is not always found at the base of the continental slope. The continental rise has a poorer flora and fauna than does the continental slope; in this respect it is more like the ocean floor.

O. K. LEONT’EV

References in periodicals archive ?
We led ODP Leg 150 last summer and drilled four sites on the slope and another site several tens of kilometers out on the continental rise.
A divergent margin consists of a gently sloping continental shelf (generally less than 130 meters deep), a steep continental slope (from the shelf edge to depths of 4,000 to 5,000 meters) that is sometimes dissected by submarine canyons, and a continental rise (where the seafloor gradient drops to below 1 meter in 40).
Most modern deposition bypasses the continental shelf and slope to form a thick wedge on the continental rise.