GEOLOGY

Detailed explanation-1: -Many rift valleys are part of “triple junctions, ” a type of divergent boundary where three tectonic plates meet at about 120° angles. Two arms of the triple junction can split to form an entire ocean. The third, “failed rift” or aulacogen, may become a rift valley.

Detailed explanation-2: -Divergent plate boundaries, which are associated with the formation of rift valleys, occur when plates move away from one another. Convergent plate boundaries move toward one another, pushing into one another and are likely to create mountain ranges.

Detailed explanation-3: -Divergent plate boundaries are characterized by shallow earthquakes, volcanic eruptions, a high topographic ridge, and very young lithosphere. [Left] Schematic of a divergent plate boundary. [Right] Iceland, where the Mid-Atlantic Ridge rises above sea level.