Divergent Plate Boundaries - cont-cont

What forms at continental - continental boundaries?

Rift valleys.

When are rift valleys formed?

When lithosphere stretches, causing it to fracture into sets of parallel faults.

What happens once parallel faults form?

The land between faults collapses into deep, wide valleys that are separated by upright blocks of land called horsts.

What is interesting about the Great African Rift Valley?

It may eventually mark the formation of a new ocean as eastern Africa splits away from the rest of its continent.

How big is the Great Rift Valley of East Africa?

Up to 120km wide and 1,500m deep.

What causes a region to be uplifted?

The rising of magma.

What does rising of magma create?

It creates weaknesses in the crust, through which low viscosity basalts emerged and flooded the area.

What is a similarity it has with oceanic ridges?

It experiences a partial collapse of the crust and the development of a deep, steep-sided rift valley.

What are the 2 sides doing in the East Africa rift valley?

They are slowly moving apart, and it is believed it will eventually flood with sea water and become a new ocean separating Africa into 2 parts.

What hazards occur at rift valleys?

Volcanic activity such as lava flows, ash fall and dangerous gases, high magnitude shallow earthquakes and ground fissures and landslides.