Pan-African orogeny


The Pan-African orogeny was a series of major Neoproterozoic orogenic events which related to the formation of the supercontinents Gondwana and Pannotia about 600 million years ago. This orogeny is also known as the Pan-Gondwanan or Saldanian Orogeny. The Pan-African orogeny and the Grenville orogeny are the largest known systems of orogenies on Earth. The sum of the continental crust formed in the Pan-African orogeny and the Grenville orogeny makes the Neoproterozoic the period of Earth's history that has produced most continental crust.

History and terminology

The term Pan-African was coined by for a tectono-thermal event at about 500 Ma when a series of mobile belts in Africa formed between much older African cratons. At the time, other terms were used for similar orogenic events on other continents, i.e. Brasiliano in South America; Adelaidean in Australia; and Beardmore in Antarctica.
Later, when plate tectonics became generally accepted, the term Pan-African was extended to all of the supercontinent Gondwana. Because the formation of Gondwana encompassed several continents and extended from the Neoproterozoic to the early Palaeozoic, Pan-African could no longer be considered a single orogeny, but rather an orogenic cycle that included the opening and closing of several large oceans and the collisions of several continental blocks. Furthermore, the Pan-African events are contemporaneous with the Cadomian orogeny in Europe and the Baikalian orogeny in Asia, and crust from these areas were probably part of Pannotia during the Precambrian.
Attempts to correlate the African Pan-African belts with the South American Brasiliano belts on the other side of the Atlantic has in many cases been problematic.

Pan-African belts

Orogenic belts comprising the Pan-African system include: