Spatial variation of soil weathering processes in the tropical high reliefs of Cameroon (Central Africa)

Year 2020, Volume: 9 Issue: 2, 92 - 104, 01.04.2020

Désiré Tsozué Simon Djakba Basga Aubin Nzeugang Nzeukou

https://doi.org/10.18393/ejss.659830

Cited By: 1

Abstract

The objective of the present work was to characterize the morphological, geochemical and mineralogical features of soil with regard to weathering processes as a function of topography and spatial variation of climate in tropical high reliefs of Cameroon. Field investigations permit to select three study sites Mbalam, Meleta and Secande respectively in the humid tropical zone, pseudotropical mountainous zone and in the tropical dry climate. Macroscopically, the studied soils are thick in Mbalam, medium thick in Meleta and relatively less thick in Secande. Globally, saprolite, a loose loamy clayey horizon and humiferous horizon were observed from the bottom to the top of the profiles. These profiles differ by their thickness, the differentiation of the saprolite horizons and the presence of humiferous horizons. They are characterized microscopically by in situ replacement of primary minerals by kaolinite/halloysite, gibbsite and iron oxides. Theses minerals are associated to anatase in Mbalam and to montmorilonite and calcite in Secande. Geochemical processes involving in the spatial differentiation of soils are monosiallitisation and allitisation in the humid tropical zone, monosiallitisation and high allitisation in the pseudotropical mountainous zone with Al2O3 content reaching 41% in the saprolite, and monosiallitisation associated to bisiallitisation in the tropical dry climate of Cameroon. The development of these geochemical processes is conditioned by topography, elevation, rainfall and temperature, which appear as the main factors responsible of the spatial variation of soil weathering processes in the tropical high reliefs of Cameroon.

Keywords

Spatial variation, weathering processes, tropical high reliefs, soil, Cameroon

References

• Aleva, G.J.J., 1994. Laterites. Concepts, geology, morphology and chemistry. International Soil Reference and Information Center, Wageningen, The Netherlands. 169p.
• Amouric, M., Olives. J., 1998. Transformation mechanisms and interstratifications in conversion of smectite to kaolinite: an HRTEM study. Clays and Clay Minerals 46(5): 521-527.
• Aristizábal, E., Roser, B., Yokota, S., 2005. Tropical chemical weathering of hillslope deposits and bedrock source in the Aburra Valley, northern Colombian Andes. Engineering Geology 81(4): 389-406.
• Beauvais, A., 1991. Paléoclimats et dynamique d’un paysage cuirassé de Centrafrique. Morphologie, pétrologie et géochimie. Thèse Doctorat, Université Poitiers, 297p. [in French]
• Beauvais, A., 2009. Ferricrete biochemical degradation on the rainforest–savannas boundary of Central African Republic. Geoderma 150(3-4): 379-388.
• Beauvais, A., Colin., F., 1993. Formation and transformation processes of iron duricrust systems in tropical humid environment. Chemical Geology 106(1-2): 77-151.
• Beauvais, A., Roquin., C., 1996. Petrological differentiation and geomorphic distribution of ferricretes in Central Africa. Geoderma 73(1-2): 63-82.
• Bétard, F., 2012. Spatial variations of soil weathering processes in a tropical mountain environment: The Baturité massif and its piedmont (Ceará, NE Brazil). Catena 93: 18-28.
• Blake, G.R., Hartge, K.H., 1986. Bulk density. In: Methods of Soil Analysis Part 1 Physical and Mineralogical Methods. 2nd Edition, Klute, A., (Ed). American Society of Agronomy,-Soil Science Society of America. Madison, Wisconsin, USA. pp. 363-375.
• Boeglin, J.L., Probst., J.L., 1998. Physical and chemical weathering rates and CO2 consumption in a tropical lateritic environment: the upper Niger basin. Chemical Geology 148(3-4): 137-156.
• Bourgeon, G., 2001. A survey of soil and weathering patterns through land system mapping in the Western Ghats region. In: Sahyadri, the great escarpment of the Indian subcontinent. Patterns of landscape development in the Western Ghats. Gunnell, Y., Radhakrishna, B.P., (Eds.). Geological Society of India, Gavipuram, India. pp 855-904.
• Bourgeon, G., Pédro, G., 1992. Rôle majeur du drainage climatique dans la différenciation altéritique et pédologique des sols des régions chaudes. Exemple du passage sols fersiallitiques-sols ferrallitiques au Sud du Karnataka (Inde). Comptes Rendus de l'Académie des Sciences. Série 2, Mécanique, Physique, Chimie, Sciences de l'Univers, Sciences de la Terre 314: 717-725. [in French]
• Braun, J.J., Ngeoupayou, J.R.N., Viers, J., Dupré, B., Bedimo, J.P., Boeglin, J.L., Robain, H., Nyeck, B., Freydier, R., Nkamdjou, L.S., Rouiller, J., Muller., J.P., 2005. Present weathering rates in a humid tropical watershed: Nsimi, South Cameroon. Geochimica et Cosmochimica Acta 69(2): 357-387.
• Colin, F., Minko, E., Nahon, D., 1989. L'or particulaire résiduel dans les profils latéritiques : altération géochimique et dispersion superficielle en conditions équatoriales. Comptes Rendus de l'Académie des Sciences 309: 553-560. [in French]
• Colin, F., Veillard, P., Ambrosi, J.P., 1993. Quantitative approach to physical and chemical gold mobility in equatorial rainforest lateritic environment. Earth and Planetary Science Letters 114(2-3): 269-285.
• Delvigne, J., 1965. Pédogenèse en zone tropicale. La formation des minéraux secondaires en milieu ferrallitique. Mém. ORSTOM, Paris, 13. 177p. [in French]
• Dumort, J.C., Peronne, Y., 1966. Notice Explicative sur la Feuille Maroua. 1 Carte géologique de Reconnaissance au1/500000. Direction des Mines et de la Géologie, Yaoundé, Cameroun. [in French]
• Dzemua, G.L., Mees, F., Stoops, G., Van Ranst E., 2011. Micromorphology, mineralogy and geochemistry of lateritic weathering over serpentinite in south-east Cameroon. Journal of African Earth Sciences 60(1-2): 38-48.
• Ehlen, J., 2005. Above the weathering front: contrasting approaches to the study and classification of weathering mantle. Geomorphology 67(1-2): 7-21.
• Gabler, R.E., ‎Petersen, J.F., ‎ Trapasso, L.M., Sack, D., 2008. Physical Geography. Ninth Edition, Brooks/Cole, Cengage learning, Belmonth, USA. 672p.
• Gardner, L.R., 1972. Conditions for direct formation of gibbsite from K-Feldspar—further discussion. American Mineralogist 57(1-2): 294-300.
• Gountié Dedzo, M., Njonfang, E., Nono, A., Kamgang, P., Zangmo Tefogoum, G., Kagou Dongmo, A., Nkouathio, D.G., 2012. Dynamic and evolution of the Mounts Bamboutos and Bamenda calderas by study of ignimbritic deposits (West-Cameroon, Cameroon Line). Syllabus Review 3: 11-23.
• Gracheva, R., 2011. Formation of soil diversity in themountainous tropics and subtropics: rocks, time and erosion. Geomorphology 135: 224-231.
• Guitián, O.F., Carballas, T., 1976. Técnicas de análisis de Suelos (Techniques of Soil Analysis). Pico Sacro: Santiago de Compostela, Spain. 288p. [in French]
• Herrmann, L., Anongrak, N., Zarei, M., Schuler, U., Spohrer, K., 2007. Factors and processes of gibbsite formation in Northern Thailand. Catena 71(2): 279-291.
• Irfan, T.Y., 1996. Mineralogy, fabric properties and classification of weathered granites in Hong Kong. Quaterly Journal of Engineering Geology and Hydrogeology 29(1): 5-35.
• Lageat, Y., Gunnell, Y., 2001. Landscape development in tropical shield environments. In: Basement regions. Godard, A., Lagasquie, J.J., Lageat, Y. (Eds.). Springer, Berlin, pp. 173-197.
• Lambe, P., 1996. Residual soils. Landslides: investigation and mitigation. In: Investigation and Mitigation. Turner, K., Schuster, R., (Eds.). Landslides Special Report, Transportation Research Board, National Research Council, pp 507-524.
• Lasserre, M., 1975. Etude de Géologique et prospection générale orientée du complexe volcano-sédimentaire Tcholliré-Bibemi-Maroua. In Mesures géochronologiques sur les formations du Nord Cameroun par les méthodes au rubidium/strontium et au potassium/argon sur minéraux et roches totales. Direction des Mines et de la Géologie Yaoundé, Cameroun. 37p. [in French]
• Letouzey, R., 1985. Notice explicative de la carte phytogéographique du Cameroun à l’échelle de 1/500 000. Institut de la Carte Internationale de la Végétation, Toulouse, France. 240p. [in French]
• Martin, D., 1966. Etudes pédologiques dans le centre Cameroun, Nanga-Eboko à Bertoua. Mém. ORSTOM, Paris, 19, 92 p.
• Martin, D., Chatelin, Y., Colllnet, J., Guichard, E., Sala, G., 1981. Les sols du Gabon. Pédogenèse, répartition et aptitudes. Notice explicative de la carte pédologique à 1:200 000. ORSTOM (éd), Paris, 92, 65p. [in French]
• Marzoli, A., Renne, P.R., Piccirillo, E.M., Francesca, C., Bellieni, G., Melfi, A.J., Nyobe, J.B., N’ni., J., 1999. Silicic magmas from the continental Cameroon Volcanic Line (Oku, Bambouto and Ngaoundere): 40Ar-39Ar dates, petrology, Sr-Nd-O isotopes and their petrogenetic significance. Contributions to Mineralogy and Petrology 135(2-3): 133-150.
• Meunier, A., 2003. Les argiles. Collection Géosciences, GB Science Publisher, 433p. [in French]
• Middelburg, J.J., Van Der Weijden, C.H., Woittiez, J.R.W., 1988. Chemical proccesses affecting the mobility of major, minor and trace elements during weathering of granitic rocks. Chemical Geology 68(3-4): 253-273.
• Morin, S., 1988. Les dissymétries fondamentales des Hautes Terres de l’Ouest-Cameroun et leurs conséquences sur l’occupation humaine. Exemple des Monts Bambouto. In: L’homme et la montagne tropicale. Bordeaux, pp 49-51.
• Muller, D., Bocquier, G., Nahon, D., Paque, H., 1981. Analyses des différenciations minéralogiques et structurales d’un sol ferrallitique à horizons nodulaires du Congo. Cah ORSTOM. Sér. Pédol. 17 : 87-109. [in French]
• Muller, J.P., 1987. Analyse pétrologique d’une formation latéritique meuble du Cameroun. Essai de traçage d’une différenciation supergène par les paragenèses secondaires. Thèse Doctorat ès Science, Université de Paris VII. 188p. [in French]
• Muller, J.P., Bocquier, G., 1986. Dissolution of kaolinites and accumulation of iron oxides in lateritic-ferruginous nodules: Mineralogical and microstructural transformations. Geoderma 37(2): 113-136.
• Nahon, D., 1991. Introduction to the Petrology of Soils and Chemical Weathering. John Wiley, New York. USA. 313p.
• Nahon, D., 2003. Weathering in tropical zone. Significance through ancient and still active mechanisms. Comptes Rendus Géoscience 335(16): 1109-1119.
• Nesbitt, H.W., Young, G.M., 1982. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites. Nature 279: 715-717.
• Ngounou Ngatcha, B., Mudry, J., Sigha Nkamdjou, L., Njitchoua, R., Naah, E., 2005. Climate variability and impacts on an alluvial aquifer in a semi-arid climate, the Logone-Chari plain (South of Lake Chad). International Association of Hydrological Sciences 295: 94-100.
• Nguetnkam, J.P., Kamga, R., Villiéras, F., Ekodeck, G.E., Yvon, J., 2008. Variable weathering response of granite in tropical zones. Example of two sequences studied in Cameroon (Central Africa). Comptes Rendus Geoscience 340(7): 451-461.
• Nono, A., Njonfang, E., Kagou Dongmo, A., Nkouathio, D.G., Tchoua, F.M., 2004. Pyroclastic deposits of the Bambouto Volcano (Cameroon Line, Central Africa): Evidence of a strombolian initial phase. Journal of African Earth Sciences 39(3-5) : 409-414.
• Novikoff, A., 1974. L'altération des roches dans le massif du Chaillu (République populaire du Congo). Formation et évolution des argiles en zone ferrallitique. Thèse Doctorat ès Science, Université Strasbourg. 298p. [in French]
• Olivry, J.C., 1986. Fleuves et rivières du Cameroun. Monographies Hydrologiques ORSTOM n°9. Ed. MESRES-ORSTOM. 733p. [in French]
• Ozaytekin, H.H., Uzum., C., 2012. Comparison of weathering rates of the soils classified in Alfisol and Entisol order developed on limestone in the Taurus Mountains at East Mediterranean region. Carpathian journal of Earth and Environmental Sciences 7(1): 109-120.
• Paquet, H., Clauer, N., 1997. Soils and sediments, Mineralogy and geochemistry. Springer-Verlag, Berlin, Heidelberg. 369p.
• Pédro, G., 1966. Essai sur la caractérisation géochimique des différents processus zonaux résultant de l’altération des roches superficielles (cycle alumino-silicique). Comptes Rendus de l'Académie des Sciences 262: 1828-1831. [in French]
• Pédro, G., 1968. Distribution des principaux types d'altération chimique à la surface du globe. Revue de Géographie Physique et de Géologie Dynamique 10: 457-470. [in French]
• Scarciglia, F., Le Pera, E., Critelli, S., 2005. Weathering and pedogenesis in the Sila Grande Massif (Calabria, South Italy): from field scale to micromorphology. Catena 61(1): 1-29.
• Sindelar, M., 2015. Soils and climate. Soil Science Society of America, international year of soils. Available at [Access date : 06.12.2018]: https://www.soils.org/files/sssa/iys/november-soils-overview.pdf
• Stoops, G., 2003. Guidelines for analysis and description of soil and regolith thin sections. Soil Science Society of America, Madison, USA., 184p.
• Suchel, J.-B., 1987. Les climats du Cameroun. Thesis, Université de Bordeaux III, France. 1186 p. [in French]
• Tardy, Y., 1993. Pétrologie des latérites et des sols tropicaux. Masson, Paris, 459p. [in French]
• Tardy, Y., Bocquier, G., Paquet, H., Millot G., 1973. Formation of clay from granite and its distribution in relation to climate and topography. Geoderma 10(4): 271-284.
• Théveniaut, H., Freyssinet, Ph., 1999. Paleomagnetism applied to lateritic profiles to assess saprolite and duricrust formation processes: the example of Mont Baduel profile (French Guiana). Palaeogeography, Palaeoclimatology, Palaeoecology 148(4): 209-231.
• Thomas, M.F., 1994. Geomorphology in the tropics. A study of weathering and denudation in low latitudes. J. Wiley & Sons, Chichester, 460p.
• Tricart, J., 1961. Les caractéristiques fondamentales du système morpho-génétique des pays tropicaux humides. L’information géographique 25: 155-169. [in French]
• USDA. 2004. Soil survey laboratory methods manual. Soil survey investigation report no. 42, Version 4.0. USDA-NCRS, Lincoln, NE, 700p.
• Velde, B., 1995. Origin and mineralogy of clays. Clays and the environment. Springer-Verlag, New York, 334p.
• Vicat, J.-P., 1998. Esquisse géologique du Cameroun. In : Géosciences au Cameroun. Vicat, J.P.,Bilong, P. (Eds.). Collect. Géocam. Press. Univ. de Yaoundé, pp 1-11. [in French]
• Voicu, G., Bardoux, M., 2002. Geochemical behavior under tropical weathering of the Barama–Mazaruni greenstone belt at Omai gold mine, Guiana Shield. Applied Geochemistry 17(3): 321-336.