What are rift valleys?

Rift valleys are geological formations that occur at divergent boundaries on land, where tectonic plates are moving apart. This process allows for the crust to thin and fracture, leading to the formation of long, narrow depressions in the Earth's surface. As the plates pull away from each other, the land between them sinks, creating a valley. This is a characteristic feature of continental rifting, which can eventually lead to the formation of new ocean basins if the rifting continues over geological time.

The formation of rift valleys is commonly associated with volcanic activity, as magma can rise to fill the gaps created by the diverging plates. Therefore, while rift valleys can experience volcanic activity, their defining characteristic is the divergent boundary itself, rather than simply high volcanic activity or other processes associated with different boundary types.