Tectonics of the Oceans

Ocean Basins Part 3

Oceanic Plate Interiors

Abyssal Plains- These are vast areas of very flat ocean floor and are the deepest regions of the oceans away from the margins. Normal oceanic crust is covered by pelagic and turbidite sediments. See Figure Below.

Oceanic Plateaus- are broad elevated regions caused by inactive volcanic arcs, rocks of continental origin or further unknown reasons. Range from a few hundred to many thousands of km's in area. Approximately 1 to 4 km above the ocean floor. Thickness is closer to continental than oceanic.
Aseismic Ridges- are linear ridges of high elevation and anomalously thick (crustal thickness close to that of island arcs) with a lack of seismic activity. (ex. Hawaiian Islands- basaltic volcanoes) The lack of seismic activity and more limited dimensions set them apart from mid-ocean ridges. See Figure Below.

Next Section, Oceanic Transform Faults and Fracture Zones