Precambrian rocks underlie approximately 60% of the country. In the southern Central African Republic
occur Precambrian lithologies belonging to the Archean Congo Craton. Palaeoproterozoic greenstone belts
(Poidevin 1994) as well as high grade Pan-African granulites (Pin and Poidevin 1987) and other Pan-
African rock suites of the North Equatorial Fold Belt underlie the central and northern part of the country.
Neoproterozoic sedimentary sequences include the Bakouma Formation with tillites, fluvioglacial deposits
and widespread carbonates (Bigotte and Bonifas 1968).
Flat-lying Cretaceous sandstones overlie parts of western and central areas.
Limestones and dolomites of the Neoproterozoic are the main carbonates in the Central African Republic.
Fine-grained but very pure limestones at Fatima, 8 km southwest of the capital Bangui are used for the
local cement industry. The United Nations Development Programme (UNDP) undertook detailed
exploration on the `Calcaires de Fatima´ with a total of 4,168 m drilled to outline blocks of extractable
limestone for the cement industry (PNUD/UNDP 1974). Proven reserves are 8 million tonnes (Gwosdz
Apart from a few Proterozoic limestones and dolomites there are considerable resources of Cretaceous
ferruginous limestones near Bakouma (Gwosdz 1996).