"Seafloor spreading" is a process that produces basalt, a rock that makes up the ocean's crust. Seafloor spreading takes place at mid-ocean ridges. Two examples of such ridges are the Mid-Atlantic Rise and the East Pacific Rise.
Several major characteristics of the seafloor are produced by seafloor spreading. The further away from the mid-ocean ridges, the older the age of the seafloor. Greater distance from the mid-ocean ridges is also characteristic of lower elevation of the seafloor. The oldest parts of the seafloor are more likely to have accumulated more sediment over time. In addition to mid-ocean ridges, seafloor spreading produces transform faults and fracture zones.