Sedimentary processes in the Carnot Formation (Central African Republic) related to the palaeogeographic framework of Central Africa

Sedimentology and depositional environments of the Red Sandstone Group, Rukwa Rift Basin, southwestern Tanzania: New insight into Cretaceous and Paleogene terrestrial ecosystems and tectonics in sub-equatorial Africa

“…In contrast, detailed sedimentological studies by Mountney et al (1998Mountney et al ( , 1999 and others have obtained important paleoenvironmental and paleoclimatic data on the earliest Cretaceous depositional systems in the Huab Basin of Namibia, but no body fossils have yet been recovered from these deposits, hampering terrestrial ecosystem reconstruction. The majority of studies on Early Cretaceous continental deposits in Zimbabwe, Zambia, Mozambique, Malawi, Tanzania, Democratic Republic of Congo (DRC), Angola, Central African Republic and Gabon were conducted by colonial geological surveys (e.g., Dixey, 1928;Cahen, 1954;Spence, 1954;Spurr, 1954;Harkin and Harpum, 1957;Grantham et al, 1958), along with limited recent studies primarily focused on regional tectonics and hydrocarbon potential (Barber, 1987;Censier and Lang, 1999;Hancox et al, 2002;Mounguengui et al, 2003). Significantly, these early sedimentological and paleontological reports on Cretaceous-Paleogene age deposits in Central Africa provide an excellent regional stratigraphic framework and have resulted in a series of isolated fossil discoveries, dominated by microfossil assemblages, fish remains and scattered terrestrial vertebrate finds, including dinosaurs.…”

Overview of Diamond Resources in Africa

“…The other, in the eastcentral region around the upper Kotto drainage, is associated with the Mouka-Oudda sandstone. Both these sandstone units are Cretaceous in age (Censier and Lang, 1999) and initial studies have suggested that their lower units are diamond-bearing. Hence, it is believed that the Mouka-Oudda and Carnot sandstones are secondary host rocks.…”

“…Given that the tributaries incise Proterozoic basement, the meta-conglomerates are considered to be diamondiferous and this is now being investigated by C&K Mining. However, it is also possible that the diamonds may be erosional residues of the Cretaceous Carnot Formation that extended from the Central African Republic (CAR) into eastern Cameroon (Censier and Lang, 1999).…”

Alluvial diamond resource potential and production capacity assessment of the Central African Republic

“…Subsequent analysis supports the assigning of the glacial Devonian-Carboniferous Mambéré Formation and the Precambrian schist and quartzite rocks as the source of the detrital materials that have been reworked and cemented into the Carnot Sandstone. The underlying Precambrian granitic-gneissic complex of rocks formed the landscape for Carnot deposition (Censier and Lang, 1999). The paleogeography and paleotopography show that this landscape was a general peneplain with monadnocks.…”

“…Deposition of the reworked material occurred from the Albian to the Maastrichtian in north-northwest-flowing riverine braided channels flowing into the Doba Trough (Chad) and into the Touboro Basin (Cameroon) (Censier and Lang, 1999). Subsequent uplift and faulting during the Cenozoic reversed the direction of flow and erosion of the Carnot from north-northwest to south-southeast and emplaced the current fluvial drainage system.…”