Origins of Birimian (ca 2.2 Ga) mafic magmatism and the Paleoproterozoic 'greenstone belt' metallogeny: a review

The Birimian of the West African Craton is an important repository of Paleoproterozoic mafic magmatism, described by many workers as petrologically dominated by basaltic to andesitic rocks. In spite of extensive work done, opinions still differ on the origin and other salient features in these globally significant igneous rocks. Even less well understood is the relationship that may exist between the mafic rocks and prolific metalliferous deposits such as manganese and gold that are hosted in these rocks. This review suggests that the frequently observed association between mafic rocks and important mineral deposits may have far more genetic implications than previously envisaged.