African Plate
From Wikipedia, the free encyclopedia
The African Plate is a tectonic plate covering the continent of Africa and extending westward to the Mid-Atlantic Ridge.
The westerly side is a divergent boundary with the North American Plate to the north and the South American Plate to the south forming the central and southern part of the Mid-Atlantic Ridge. The African plate is bounded on the northeast by the Arabian Plate, the southeast by the Indo-Australian Plate, the north by the Eurasian Plate, and the south by the Antarctic Plate. All of these boundaries are divergent or spreading boundaries with the exception of the northern boundary with the Eurasian Plate.
The African Plate comprises several continental blocks or cratons, stable continental blocks of old rocks, which came together to form the African continent during the assembly of the supercontinent Gondwana around 550 million years ago. These cratons are, from south to north, the Kalahari, Congo, Sahara and West African craton. Each of these cratons can further be subdivided into even smaller blocks or terranes, sutured along pre-Gondwanan orogenic belts.
The African Plate is rifting in the eastern interior along the tectonically and volcanically active Afar Triangle and Great Rift Valley. This rift zone separates the Nubian subplate to the west from the Somalian subplate to the east. A mantle plume is proposed to exist beneath the Afar region.
The African Plate's speed is estimated at around 2.15 centimeters per year. At this rate the continent of Africa should touch the southern tip of Spain in about 650,000 years, closing the Mediterranean Sea.
