Passive Continental Margin

A **passive margin** is the boundary between the lithosphere of an ocean and a continent characterized by tectonic inactivity. The continental crust is primarily composed of granite, whereas the oceanic crust consists of basalt; although both are igneous rocks, they differ in composition. Submarine canyons are distinctive features of continental slopes, appearing as steep, V-shaped valleys that can reach depths of several thousand feet. These canyons sometimes extend to the outer edge of the continental shelf. Influenced by these structures, turbidity currents, consisting of water and sediment, are created from major rivers entering the ocean. Upon reaching the ocean floor, these currents slow, depositing sediment in a fanlike formation. The base of the continental slope is covered by a thick layer of gently spread sediment originating from land, known as terrestrial deposits, which form a transitional zone between the ocean basin and the continental slope.