Carbonate resources of Cameroon and potential applications. – C. M. Agyingi, J. Foba-Tendo, A. F. Epanty, F. A. Zisuh and A. Z. Ongbwa.
ABSTRACT
Carbonate deposits are known to occur in three geologic settings in Cameroon including sedimentary, igneous and metamorphic terrains. These carbonates include limestones, dolomitic limestones, marl, marble, travertine and carbonatites. Sedimentary carbonate deposits outcrop in the Douala basin in the Mungo valley, Kompina and Logbajeck; in the Mamfe basin along the banks of the Manyu River; in the Rio del Rey basin around the Moko River and in the Figuil basin around Figuil. Chemical analyses have revealed a CaCO3 content of 75-93% for the Mungo Valley deposits, 35-51% for Moko River, 50-92% for the Kompina, and 81-98% for Figuil. Igneous carbonate deposits (travertines) occur along the Cameroon Volcanic Line at Bongogo in Ndian Division, Etam close to Kumba and Manjo. These deposits are limited in extent and chemical analyses have shown a CaCO3 content of 98% for the three deposits. Other igneous carbonates are boulders and cobbles of carbonatites that have been observed scattered over an area of about 10 hectares in Likomba close to Tiko. Metamorphic carbonates (marble) occur in Bidzar, a village along the Garoua-Maroua road with a CaCO3 content of up to 95% and estimated reserves of 2.500.000tons. Those carbonates that are calcite-rich (>90% CaCO3) are suitable for the manufacture of portland cement. Deposits in this category include those at Figuil and Bidzar (which are already being exploited), Kompina and the Mungo Valley. The Kompina samples are dolomitic and can be used as aglime (agricultural lime). The calcite poor deposits from Moko can also be used for liming of soils and for the treatment of acidic industrial waste. Although the travertines are calcite rich, the quantities are very limited and hence cannot serve as viable raw materials for cement production. They can however be exploited for artisanal lime production.