marginal plateau[′mär·jən·əl pla′tō]
a relief element of the continental slope. It is a relatively flat step tilted in the direction of the ocean, with a width of up to several hundred kilometers (more frequently dozens of kilometers). It is assumed that the marginal plateaus were formed by the tectonic subsidence of sections of the continental shelf, because the geologic structure of the plateaus usually resembles the adjacent parts of the shelf. Examples of marginal plateaus are the Blake Plateau east of Florida and the Chukchi Plateau in the Arctic Ocean.