Editing Africa (section)

=== Geological History ===

The vast African continental platform, composed of archaic, crystalline rock, dates back to the Precambrian period, the same geological epoch in which the Brazilian plateau in South America was formed. It extends south from the Atlas Mountains to the Cape of Good Hope; to the east it reappears in the Arabian Peninsula and Madagascar, which separated from Africa during the Cenozoic (Tertiary) period. Within these ancient rocks, however, covered over vast areas by various sedimentary formations, the very first traces of life on Earth have been brought to light: fossil microorganisms dating back 3.2 billion years. Geologically, the Atlas Mountains (in northwestern Africa) are part of the foldings of the Mediterranean area, that is, the ancient Tethys basin. They originated from the same movements that formed the Alpine chain and other "young" mountain ranges of Europe.

The tectonic forces that separated Africa from South America during the breakup of the supercontinent Gondwana, about 150 million years ago, continued to act in more recent times, creating the Rift Valley during the Tertiary period and causing the eruptions that led to the formation of the volcanic cones of Mount Kenya and Kilimanjaro in East Africa.