Unique geomorphologic features in ocean basins
Abyssal plains
- Lie beneath 3.5-5 km of water
- Nearly level, often featureless plains
- Abyssal hills rise <1 km above abyssal plains
- Seamounts rise >1 km above abyssal plains
- Sea floor sedimentary rocks are distinct from those found near continents
- Basement is basalts or gabbros