OJG  Vol.2 No.1 , January 2012
Multi-Scale Organization of the Doumbouo-Fokoué Bauxites Ore Deposits (West Cameroon): Implication to the Landscape Lowering
Abstract: Landscape distribution, macroscopic, microscopic, mineral and geochemical characterizations were conducted on the Doumbouo-Fokoué bauxite ore deposit in order to estimate bauxites potential and its implication to general lowering of the relief. Fourteen bauxitic plateaus covering a surface area of 5.7 km2 were identified. Bauxitic pedons show deep weathered profiles (10.0 - 12.0 m) with thick bauxitic mantle (4.0 - 8.0 m). Saprolite and pisolith bauxitic facies own high aluminium (47.5% - 49.5% Al2O3), relatively low iron (20.0% - 22.0% Fe2O3) and low silica contents (1.8% - 7.6% SiO2). Gibbsite is the dominant mineral (49% - 68% of minerals detected by X-ray); meanwhile hematite, goethite and kaolinite occur in small amounts. Bauxitization corresponds to intense allitization with abundant accumulation of gibbsite and development of lateritic iron bearing ortho-bauxites. Bauxite ores yielded bauxite reserves of 9.2 million tons. They occur as old and residual bauxitic mantles representing remnants of the Miocene residual lateritic deposits in West Cameroon referring to the African surface of Valeton [1]. Its mean altitude (1532 - 1590 m als) below the African surface reveals general lowering of the relief.
Cite this paper: M. Mathieu, T. Paul and Y. Martin, "Multi-Scale Organization of the Doumbouo-Fokoué Bauxites Ore Deposits (West Cameroon): Implication to the Landscape Lowering," Open Journal of Geology, Vol. 2 No. 1, 2012, pp. 14-24. doi: 10.4236/ojg.2012.21002.

[1]   I. Valeton, “Saprolite-Bauxite Facies of Ferralitic Duri- crusts on Palaeosurfaces of Former Pangaea,” In: M. Thiry and R. Simon-Coincon, Eds., Palaeoweathering, Palaeosurfaces and Related Continental Deposits, International Association of Sedimentology, Vol. 27, 1999, pp. 153- 188.

[2]   G. Bardossy, G. Aleva and G. J. J. Lateritic Bauxites, “Developments in Economic Geology,” Elsevier, Amsterdam, 1990, pp. 27, 624.

[3]   E. Lee Bray, “US Geological Survey, Mineral Commodity Summaries,” United States Government Printing Office, Washington, 2009.

[4]   B. Kobilseck, “Géochimie et Pétrographie des Bauxites Latéritiques d’Amazonie Brésilienne, Comparaison Avec l’Afrique, l’Inde et l’Australie,” Thèse Université Louis Pasteur, Strasbourg, 1990.

[5]   W. Edlinger, “Contribution to Geology and Petrography of the German Adamawa,” Ph.D. Thesis, Erlangen Uni- versity, Erlangen, 1908.

[6]   S. Passarge, “The Superficial Structure and Geology of Cameroon,” Annual Review of German Colonies, 1910, pp. 448-465.

[7]   G. Weeksteen, “Preliminary Report on the Fongo Tongo Bauxite ore Deposits,” Report of the Mine and Geology of the Cameroon State, 1957.

[8]   S. M. Eno Belinga, “L’Altération des Roches Basaltiques et le Processus de Bauxitisation dans l’Adamaoua (Cameroun),” Thèse Doctorat Etat, Université Paris VI, Paris, 1972, p. 571.

[9]   B. Hieronymus, “Study of the Weathering of Eruptive Rocks in the West Cameroon,” Earth Science Thesis, University of Paris VI, Paris, 1985, p. 85.

[10]   J. B. Nyobe, “A Geological and Geochemical Study of the Fongo-Tongo and Areally Related Bauxites Depo- sits,” Ph.D. Thesis, Western Highlands, Camroon, 1987.

[11]   M. Sojien, “Etude Pétrographique, Minéralogique et Géochimique des Formations Bauxitiques de Bangam dans les Hautes Terres de l’Ouest Cameroun,” Thèse MSc., Université Dschang, Dschang, 2007, p. 77.

[12]   P. Ntep, “Minerals Resources of the West Region Sub- Divisions,” The Thematic Ores Resources Map of the Cameroon, Yaoundé, 2009.

[13]   B. Deruelle, C. Moreau, R. Kambou, J. Lissom, E. Njonfang, R. T. Ghogomu and A. Nono, “The Cameroon Line: A Review,” In: A. B. Kampuzu and R. T. Lubal, Eds., Magmatism in Extensional Structural Settings, Springer-Verlag, Berlin, 1991, pp. 274-327.

[14]   M. Kwekam, J. P. Liégeois, E. Njonfang, P. Affaton and G. Hartmann, “Nature, Origin and Significance of the Fomopéa Pan-African High-K Calc-alkaline Plutonic Complex in the Central African Fold Belt (Cameroon),” Journal of African Earth Sciences, Vol. 57, 2010, pp. 79-95.

[15]   D. G. Nkouathio, D. A. Kagou, J. M. Bardintzeff, P. Wandji, H. Bellon and A. Pouclet, “Evolution of Volcanism in Graben and Horst Structures Along the Cenozoic Cameroon Line (Africa): Implications for Tectonic Evolution and Mantle Source Composition,” Mineralogy and Petrology, Vol. 94, 2008, pp. 287-303.

[16]   R. Maignien, “Manuel Pour la Description des Sols sur le Terrain,” Document ORSTOM, Paris, 1980, p. 112.

[17]   D. Njopwouo, “Minéralogie et Physicochimie des Argiles de Bomkoul et de Balengou (Cameroun). Utilisation dans la Polymérisation du Styrène et Dans le Renforcement du Caoutchouc Naturel,” Thèse Doctorat Etat, Université Yaoundé, Yaoundé, 1984, p. 300.

[18]   K. A. Rahn and R. J. Mc Cafrey, “Compositional Differences between Arctic Aerosol and Snow,” Nature, Vol. 280, 1979, pp. 479-480.

[19]   B. Boulange, A. Carvalho and A. J. Melfi, “Geochemical Characteristics of African and Brazilian Bauxites Deposits: SiO2-Al2O3-Fe2O3 System and Ti, Cr, V and Fe2O3 Relations,” Geochemistry Earth Surface and Mineral Formation Symposium, 2-8 July 1990, Aix-en-Provence, pp. 30-32.

[20]   G. Certini, M. J. Wilson, S. J. Hillier, A. R. Fraser and E. Delbos, “Mineral Weathering in Trachydacitic-Derived Soils and Saprolites Involving Formation of Embryonic Halloysite and Gibbsite at Mt Amiata, Central Italy,” Geoderma, Vol. 133, No. 3-4, 2006, pp. 173-190.

[21]   E. Aristizabal, B. Roser and S. Yokota, “Tropical Chemi- cal Weathering of Hillslope Deposits and Bedrock Source in the ABURRA Valley, Northern Colombian Andes,” Engineering Geology, Vol. 81, 2005, pp. 389-406.

[22]   M. K. D. Mutakyahwa, J. R. Ikingura and A. H. Mruma, “Geology and Geochemistry of Bauxite Deposits in Lushoto District, Usambara Mountains, Tanzania,” Jour- nal of African Earth Sciences, Vol. 6, 2003, pp. 357-369.

[23]   B. Boulange, “Les Formations Bauxitiques Latéritiques de C?te d’Ivoire, ” Travaux et Document ORSTOM, Vol. 175, 1984, p. 341.

[24]   J. Thorez, “Argilloscopy of Weathering and Sedimentation,” Bulletin Société Géologique, Vol. 98, No. 2, 1989, pp. 245-267.

[25]   J. C. Leprun, “Géochimie de Surface et Formes de Relief. IV. la Dégradation des Cuirasses Ferrugineuses. Etude et Importance du Phénomène Pédologique en Afrique de l’Ouest,” Science Géologique Bulletin, Vol. 30, No. 4, 1977, pp. 265-273.

[26]   Mazaltarim, “Géochimie des Cuirasses Bauxitiques de l’Afrique Occidentale et Centrale,” Thèse Université Louis Pasteur, Strasbourg, 1989, p. 263.

[27]   A. Bourdeau, “Les bauxites du Mali. Géochimie et Minéralogie,” Thèse Université Louis Pasteur, Strasbourg, 1991, p. 329.

[28]   A. Beauvais and Y. Tardy, “Degradation and Dismantling of Iron Crust under Climatic Changes in Central Africa,” Chemical Geology, Vol. 107, No. *, 1993, pp. 277-280.

[29]   Y. Tardy and D. Nahon, “Geochemistry of Laterites Stability of Al-Goethite, Al-Hematite and Fe-Kaolinite in Bauxites and Ferricretes: An Approach to the Mechanism of Concretion Formation,” American Journal Sciences, Vol. 285, No. 10, 1985, pp. 865-903.

[30]   Y. Tardy, A. J. Melfi and I. Valeton, “Climats et Paléo- climats Tropicaux Péri Atlantiques. R?le des Facteurs Climatiques et Thermodynamiques (Température et Activité de l’Eau) sur la Répartition et la Composition Minéra- logique des Bauxites et des Cuirasses Ferrugineuses au Brésil et en Afrique,” Compte Rendu Académie Science, Vol. 306, No. 2, 1988, pp. 289-295.

[31]   I. Valeton and A. J. Melfi, “Distribution Pattern of Bauxites in Cataguases Area (SE-Brazil) in Relation to Lower Tertiary Paleogeography and Younger Tectonics,” Sci- ence Géologie Bulletin, Vol. 41, No. 1, 1988, pp. 85-98.

[32]   Y. Boulvert, “Aplanissement en Centrafrique. Relation avec le Cuirassement, la Tectonique, le Bioclimat. Pro- Blèmes Posés. Progrès des Connaissances,” Bulletin Asso- ciation Géographes Fran?ais, Vol. 4, 1985, pp. 301-309.

[33]   G. J. Churchman, “The Alteration and Formation of Soil Minerals by Weathering. Handbook of Soil Science,” M. E. Sumner, Ed., Handbook of Soil Science, CRC Press, Boca Raton, 2000, pp. 3-76.

[34]   P. Tematio and K. R. Olson, “Characterization of Two Phases of Encrustment in a Sequence of Ferrallitic Soils in the South Cameroon and Its Effects on Landscape Evolution,” Soil Sciences, Vol. 162, No. 10, 1997, pp. 758-766.

[35]   E. Temgoua, D. Bitom, P. Bilong, Y. Lucas and H. R. Pfeifer, “Démantèlement des Paysages Cuirassés Anciens en Zones Forestières Tropicales d’Afrique Centrale: Formation des Accumulations Ferrugineuses Actuelles en Bas de Ver- sants,” Compte Rendu Géoscience, Vol. 334, No. 8, 2002, pp. 537-543.

[36]   D. Bitom, B. Volkoff and M. Abossolo-Angue, “Evolution and Alteration in Situ of Massive Iron Duricrusts in Central Africa,” Journal of African Earth Sciences, Vol. 37, 2003, pp. 89-101.

[37]   P. Bilong, S. M. Eno Belinga and B. Volkoff, “Séquence D’évolution des Paysages Cuirassés et des Sols Ferra- llitiques en Zones Forestières Tropicales d’Afrique Centrale. Place des Sols à Horizons d’Argile Tachetée,” Compte Rendu Académie Science, Vol. 314, No. 2, 1992, pp. 109-115.