1. Rift valleys
A rift valley is a linear-shaped lowland between several highlands or mountain ranges created by the action of a geologic rift or fault.

2. Formation of rift valleys
A rift valley is formed on a divergent plate boundary, The surface spreads apart, and central section between plates is subsequently further deepened by the forces of erosion. When the tensional forces were strong enough to cause the plate to split apart, a center block dropped down between the two blocks at its flanks, forming a graben. This drop of the center creates the nearly parallel steeply dipping walls of rift valley when it is new. This feature is the beginning of the rift valley, but as the process continues, the valley widens, until it becomes a large basin, that fills with sediment from the rift walls and the surrounding area. One of the most well known examples of this process is the East African Rift

3. A rift valley is formed by the forces of a geological rift, or fault, when the tension of the tectonic plates causes a central block of land to sink lower than the two sides, which is then further eroded by the weather.