CAS ES 142 Lecture Notes - Lecture 10: Plate Tectonics, Submarine Canyon, Mantle Plume
22 Feb 2017
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High rainfall rates - receives 10m of precipitation per year. Considering a single mantle plume, the doming and rifting process produces a three-arm tear in the lithosphere. As the mantle plume spreads laterally beneath the lithosphere, two of the rift valleys widen and deepen, while the third arm of the rift becomes inactive. The third arm fails because the pressure of the mantle plume is relieved by the continued spreading of the other two arms of the rift. The failed third arm is a low-lying valley, portions of which are below sea level, extends into the african continent. Wide shelf --> submarine canyon is further from shoreline. Narrow shelf --> submarine canyon is closer to shoreline. The east coast is an amero-trailing edge, it faces a spreading zone (opposite side of the continent is a collision coast). Drainage areas are surrounded by drainage divides (mountains).
