* The African Plate: The majority of the Rift Valley is situated on the African Plate.

* The Somali Plate: This smaller plate is breaking away from the African Plate. This separation is what is driving the formation of the Rift Valley.

* The Arabian Plate: The northern part of the Rift Valley (specifically the Red Sea) is formed by the Arabian Plate moving away from the African Plate.

The Great Rift Valley is a divergent plate boundary, meaning that the plates are moving apart from each other. This movement creates tension in the Earth's crust, which leads to the formation of faults, volcanoes, and eventually, a rift valley.