The relief depends on the structure of the earth’s crust, which was formed for a long time. Under the influence of internal and external processes, the main tectonic structures of Africa emerged and deposits of various minerals were formed to the origin.
Covered 2-3 billion years ago, Africa’s high mountain systems under the influence of the Earth’s external forces collapsed. Thus, the ancient African-Arabian platform was formed, which now forms the basis of the continent. During a long geological history, individual sections of the platform were raised. Its foundation came to the surface, and shields arose. In other places, the sites of the ancient platform fell, its foundation was deeply submerged under a thick sedimentary cover, which led to the appearance of large depressions. These movements of the plates were accompanied by faults in the earth’s crust, volcanic eruptions, and earthquakes.
For a long time, Africa was part of the ancient continent of Gondwana. As an independent continent, Africa began to form in the middle of the Mesozoic era, about 180 million years ago, when Gondwana rolled.... Complete separation of Africa from South America and other parts of Gondwana occurred already at the beginning of the Cenozoic era about 65 million years ago.
At the same time, the African lithospheric plate was formed, in the center of which much of modern Africa is located. This is the reason for the relative seismic stability of the territory of most of the continent. Only the extreme north and north-western parts of the continent lie at the junction of neighboring lithospheric plates. Here are the most seismically active areas of the continent.
In the Cenozoic era, the African lithospheric plate in the east began to split by a system of deep faults into two parts. Currently, East Africa has one of the most ambitious geological formations on Earth – the East African Rift – fault zone, which continues to expand. Rift valley stretches from the Red Sea to the south along the line of African lakes. These ponds are deep faults of the earth’s crust, filled with water. Earthquakes and volcanic eruptions occur along the rift valley.