The Congo Craton outcrops in Cameroon,Gabon and in the Republic of Congo where it is dominantly comprised of ArchaeanTonalite-Trondhjemite-Granodiorite (TTG) gneisses ranging ~3100–2800Ma. The northern portion is known as the NtemComplex, in Cameroon, and the southern portion as the East GabonianBlock comprised of a northern North Gabon Massif and a southern ChailluMassif. These two geological entities are separated by the PaleaoproterozoicFrancevillianSupergroup.
Greenstone belts comprised of Banded Iron Formations (BIF), metasedimentsand metavolcanicsare incorporated within the Archaean basement gneisses and are thought to have deposited between 2870 and 2750 Ma in Gabon.
