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Climate-induced fluvial dynamics in tropical Africa around the last glacial maximum?

Published online by Cambridge University Press:  20 January 2017

Mark Sangen*
Affiliation:
Institute of Physical Geography, Goethe-University, Campus Riedberg, Altenhoefer Allee 1, 60438 Frankfurt am Main, Germany
Katharina Neumann
Affiliation:
Institute of Archaeological Sciences, Department of Pre- and Protohistory, Goethe-University, Grueneburgplatz 1, 60323 Frankfurt am Main, Germany
Joachim Eisenberg
Affiliation:
Institute of Physical Geography, Goethe-University, Campus Riedberg, Altenhoefer Allee 1, 60438 Frankfurt am Main, Germany
*
Corresponding author. Fax: + 49 69 798 40169. E-mail addresses:[email protected] (M. Sangen), [email protected](M. Sangen), [email protected] (K. Neumann), [email protected] (J. Eisenberg).

Abstract

The alluvia of the Ntem, Nyong and Sanaga fluvial systems in southern Cameroon recorded repeated fluvial activity fluctuations during the Late Pleistocene, including the last glacial maximum (LGM), the beginning of the African Humid Period and the northern hemispheric Bølling-Allerød. We applied a multi-proxy approach on alluvial stratigraphies dated between 22.4 and 13.0 cal ka BP, including remote sensing, sedimentological and morphogenetic methods, phytoliths, sponge spicules, 14C and δ13C data. A distinct NE–SW gradient of landscape and fluvial dynamics around the LGM can be drawn, with evidence for the persistence of extended fluvial rainforest refuges only in the Ntem catchment. The Sanaga and Nyong catchment areas were characterized by frequent channel migrations, floodplain reorganization and unstable vegetation subject to fire, including grasslands, woodlands, and gallery forests with bamboo thickets. In spite of increasing rainfall after 16.4 cal ka BP, persisting landscape instability played the major role for fluvial system dynamics, floodplain transformations and vegetation development until 13.0 cal ka BP, before a general landscape stabilization and rainforest expansion set in at the beginning of the Holocene.

Type
Research Article
Copyright
University of Washington

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Footnotes

1 Fax: + 49 69 798 32104.
2 Fax: + 49 69 798 40169.

References

Adegbie, A.T., Schneider, R.R., Röhl, U., and Wefer, G. Glacial millennial-scale fluctuations in central African precipitation recorded in terrigenous sediment supply and freshwater signals offshore Cameroon. Palaeogeography, Palaeoclimatology, Palaeoecology 197, (2003). 323333.CrossRefGoogle Scholar
Albert, R.M., and Weiner, S. Study of phytoliths in prehistoric ash layers using a quantitative approach. Meunier, J.D., and Colin, F. Phytoliths: Applications in Earth Sciences and Human History. (2001). Balkema Publishers, Lisse, Netherlands. 251266.Google Scholar
Albert, R.M., Bamford, M.K., and Cabanes, D. Taphonomy of phytoliths and macroplants in different soils from Olduvai Gorge (Tanzania) and the application to Plio-Pleistocene palaeoanthropological samples. Quaternary International 148, (2006). 7894.CrossRefGoogle Scholar
Alexandre, A., Meunier, J.-D., Lézine, A.-M., Vincens, A., and Schwartz, D. Phytoliths: indicators of grassland dynamics during the late Holocene in intertropical Africa. Palaeogeography, Palaeoclimatology, Palaeoecology 136, (1997). 213229.CrossRefGoogle Scholar
Alexandre, A., Meunier, J.-D., Mariotti, A., and Soubies, F. Late Holocene phytolith and carbon-isotope record from a latosol at Salitre, South-Central Brazil. Quaternary Research 51, (1999). 187194.CrossRefGoogle Scholar
Anhuf, D., Ledru, M.-P., Behling, H., Da Cruz, F.W., Cordeiro, R.C., Van der Hammen, T., Karmann, I., Marengo, J.A., De Oliveita, P.E., Pessenda, L., Siffedine, A., Albuquerque, A.L., and Da Silva Dias, P.L. Paleo-environmental change in Amazonian and African rainforest during the LGM. Palaeogeography, Palaeoclimatology, Palaeoecology 239, (2006). 510527.CrossRefGoogle Scholar
Barboni, D., Bonnefille, R., Alexandre, A., and Meunier, J.D. Phytoliths as palaeoenvironmental indicators, West Side Middle Awash Valley, Ethiopia. Palaeogeography, Palaeoclimatology, Palaeoecology 152, (1999). 87100.CrossRefGoogle Scholar
Barboni, D., Bremond, L., and Bonnefille, R. Comparative study of modern phytolith assemblages from inter-tropical Africa. Palaeogeography, Palaeoclimatology, Palaeoecology 246, (2007). 454470.CrossRefGoogle Scholar
Bremond, L., Alexandre, A., Hély, C., and Guiot, J. A phytolith index as a proxy of tree cover density in tropical areas: calibration with Leaf Area Index along a forest–savanna transect in southeastern Cameroon. Global and Planetary Change 45, (2005). 277293.CrossRefGoogle Scholar
Bremond, L., Alexandre, A., Wooller, M.J., Hely, C., Williamson, D., Schäfer, P.A., Majule, A., and Guiot, J. Phytolith indices as proxies of grass subfamilies on East African tropical mountains. Global and Planetary Change 61, 3–4 (2008). 209224.CrossRefGoogle Scholar
Broccoli, A.J., Dahl, K.A., and Stouffer, R.J. Response of the ITCZ to Northern hemisphere cooling. Geophysical Research Letters 33, (2006). L01702 doi:http://dx.doi.org/10.1029/2005GL024546CrossRefGoogle Scholar
Burke, K. The African Plate. South African Journal of Geology 99, (1996). 341409.Google Scholar
Chauvel, A., Walker, I., and Lucas, Y. Sedimentation and pedogenesis in a Central Amazonian Black water basin. Biogeochemistry 33, (1996). 7795.CrossRefGoogle Scholar
Chiang, J.C.H., Biasutti, M., and Battisti, D.S. Sensitivity of the Atlantic Intertropical Convergence Zone to last glacial maximum boundary conditions. Palaeoceanography 18, (2003). 1094 http://dx.doi.org/10.1029/2003PA000916CrossRefGoogle Scholar
Clarke, J. The occurrence and significance of biogenic opal in the regolith. Earth-Science Reviews 60, (2003). 175194.CrossRefGoogle Scholar
De Ploey, J. Cartographie geomorphologique et morphogenese aux environs du Stanley-Pool (Congo). Acta Geographica Lovaniensia 3, (1964). 431441.Google Scholar
De Ploey, J. Position géomorphologique, génèse et chronologie de certains dépots superficiels du Congo occidental. Quaternaria 7, (1965). 131154.Google Scholar
DeMenocal, P., Ortiz, J., Guilderson, T., Adkins, J., Sarnthein, M., Baker, L., and Yarusinsky, M. Abrupt onset and termination of the African Humid Period: rapid climate responses to gradual insolation forcing. Quaternary Science Reviews 19, (2000). 347361.CrossRefGoogle Scholar
Dumont, J.F. Identification par télédétection de l'accident de la Sanaga (Cameroun). Sa position dans le contexte des grands accidents d'Afrique centrale et de la limite nord du craton congolais. Géodynamique 1, 1 (1986). 1319.Google Scholar
Dupont, L.M., Jahns, S., Marret, F., and Ning, S. Vegetation changes in equatorial West Africa: time slices for the last 150 ka. Palaeogeography, Palaeoclimatology, Palaeoecology 155, (2000). 95122.CrossRefGoogle Scholar
Eisenberg, J. A palaeoecological approach to neotectonics: the geomorphic evolution of the Ntem River in and below its interior delta, SW Cameroon. Palaeoecology of Africa 28, (2008). 259271.Google Scholar
Eisenberg, J.1, (2009). Morphogenese der Flusseinzugsgebiete von Nyong und Ntem in Süd-Kamerun unter Berücksichtigung neotektonischer Vorgänge. PhD-thesis, J.W.Goethe-University Frankfurt, 1219.Google Scholar
Elenga, H., Schwartz, D., Vincens, A., Bertaux, J., de Namur, C., Martin, L., Wirrmann, D., and Servant, M. Diagramme pollinique holocène du Lac Kitina (Congo): mise en évidence de changements paléobotaniques et paléoclimatiques dans le massif forestier du Mayombe. Comptes Rendus de l'Academie des Sciences 323, Series IIA (1996). 403410.Google Scholar
Elenga, H., Maley, J., Vincens, A., and Farrera, I. Palaeoenvironments, palaeoclimates and landscape development in Atlantic equatorial Africa: a review of key sites covering the last 25 ka. Battarbee, R.W., Gasse, F., and Stickley, C.E. Past Climate Variability Through Europe and Africa. (2004). Springer, 181198.Google Scholar
Fredlund, G.G., and Tieszen, L.T. Modern phytolith assemblages from the North American Great Plains. Journal of Biogeography 21, (1994). 321335.CrossRefGoogle Scholar
Gasse, F. Hydrological changes in the African tropics since the Last Glacial Maximum. Quaternary Science Reviews 19, (2000). 189211.CrossRefGoogle Scholar
Gasse, F., Chalié, F., Vincens, A., Williams, M.A.J., and Williamson, D. Climatic patterns in equatorial and southern Africa from 30,000 to 10,000 years ago reconstructed from terrestrial and near-shore proxy data. Quaternary Science Reviews 27, (2008). 23162340.CrossRefGoogle Scholar
Hamilton, A. The significance of patterns of distribution shown by forest plants and animals in tropical Africa for the reconstruction of upper Pleistocene palaeoenvironments: a review. Palaeoecology of Africa 9, (1976). 6397.Google Scholar
Hamilton, A.C. Environmental history of East Africa - A study of the Quaternary. (1982). Academic Press, New York, London. 1328.Google Scholar
Harrison, F.W. Methods in Quaternary Ecology #4. Freshwater sponges. Geosciences Canada 15, 3 (1988). 193198.Google Scholar
Hughen, K., Southon, J., Lehman, S., Bertrand, C., and Turnbull, J. Marine-derived 14C calibration and activity record for the past 50,000 years updated from the Cariaco Basin. Quaternary Science Reviews 25, (2006). 32163227.CrossRefGoogle Scholar
ICPN Working Group Madella, M., Alexandre, A., and Ball, T. International code for phytolith nomenclature 1.0. Annals of Botany 96, (2005). 253260.CrossRefGoogle ScholarPubMed
Jahns, S. Vegetation history and climate changes in West Equatorial Africa during the Late Pleistocene and Holocene, based on a marine pollen diagram from the Congo fan. Vegetation History and Archaeobotany 5, (1996). 207213.CrossRefGoogle Scholar
Kadomura, H. Palaeoecological and palaeohydrological changes in the humid tropics during the last 20.000 years, with reference to Equatorial Africa. Gregory, K.J., and Starkel, L.V. Global Continental Palaeohydrology. (1995). Wiley, 177202.Google Scholar
Kuete, M., (1990). Géomorphologie du plateau sud-Camerounais à l'ouest du 13°E. PhD-thesis, Université de Yaoundé 1, .Google Scholar
L’Hôte, Y., Mahé, G., (1996). Afrique de l'Ouest et Centrale, Précipitations moyennes annuelles (période 1951-1989). Echelle 1/6 000 000 ème. Collection des cartes ORSTOM, ORSTOM Ed., Paris.Google Scholar
Ledru, M.-P., Bertaux, J., Sifeddine, A., and Suguio, K. Absence of last glacial maximum records in lowland tropical forests. Quaternary Research 49, (1998). 233237.CrossRefGoogle Scholar
Lejju, J.B., Taylor, D., and Robertshaw, P. Late-Holocene environmental variability at Munsa archaeological site, Uganda: a multicore, multiproxy approach. The Holocene 15, 7 (2005). 10441061.CrossRefGoogle Scholar
Lespez, L., Le Drezen, Y., Garnier, A., Rasse, M., Eichhorn, B., Ballouche, A., Neumann, K., and Huysecom, E. High-resolution fluvial records of Holocene environmental changes in the Sahel: the Yamé River at Ounjougou (Mali, West Africa). Quaternary Science Reviews 30, (2011). 737756.CrossRefGoogle Scholar
Lézine, A.-M., and Cazet, J.P. High-resolution pollen record from core KW31, Gulf of Guinea, documents the history of the lowland forests of West Equatorial Africa since 40,000 yr ago. Quaternary Research 64, (2005). 432443.CrossRefGoogle Scholar
Lézine, A.-M., Duplessy, J.C., and Cazet, J.P. West African monsoon variability during the last deglaciation and the Holocene: evidence from fresh water algae, pollen and isotope data from core KW31, Gulf of Guinea. Palaeogeography, Palaeoclimatology, Palaeoecology 219, (2005). 225237.CrossRefGoogle Scholar
Macklin, M.G., and Lewin, J. Alluvial responses to changing Earth system. Earth Surface Processes and Landforms 33, (2008). 13741395.CrossRefGoogle Scholar
Makaske, B. Anastomosing rivers. Forms, Processes and Sediments. Nederlandse Geografische Studies 249, (1998). Faculteit Ruimtelijke Wetenschappen, University Utrecht, Google Scholar
Makaske, B. Anastomosing rivers: a review of their classification, origin and sedimentary products. Earth-Science Reviews 53, (2001). 149196.Google Scholar
Maley, J. Late Quaternary climatic changes in the African rain forest: forest refugia and the major role of sea surface temperature variation. Leinen, M., and Sarnthein, M. Paleoclimatology and Paleometeorology: Modern and Past Patterns of Global Atmospheric Transport. NATO ASI Series, Series C: Mathematical and Physical Sciences 282, (1989). 585616.Google Scholar
Maley, J. The impact of arid phases on the African rain forest through geological history. Weber, W., White, L., Vedder, A., and Naughton-Treves, L. African Rain Forest Ecology and Conservation. (2001). Yale University Press, 6887.Google Scholar
Maley, J., and Brenac, P. Vegetation dynamics, paleoenvironments and climatic changes in the forests of western Cameroon during the last 28,000 years B.P.. Review of Palaeobotany and Palynology 99, (1998). 157187.CrossRefGoogle Scholar
Manconi, R., and Pronzato, R. Atlas of African freshwater sponges. Studies in Afrotropical Zoology 295, (2009). Royal Museum for Central Africa, Tervuren.Google Scholar
Marret, F., Scourse, J.D., Jansen, F.J.H., and Schneider, R. Changements climatiques et paléocéanographiques en Afrique centrale atlantique au cours de la dernière déglaciation: contribution palynologique. Comptes rendus de l'Académie des Sciences Serie II Fasc. A—Sciences de la Terre et des Planètes 329, (1999). 721726.Google Scholar
Marret, F., Scourse, J.D., Versteegh, G., Jansen, F.J.H., and Schneider, R. Integrated marine and terrestrial evidence for abrupt Congo River palaeodischarge fluctuations during the last deglaciation. Journal of Quaternary Science 16, (2001). 761766.CrossRefGoogle Scholar
Marret, F., Maley, J., and Scourse, J. Climatic instability in west equatorial Africa during the Mid- and Late Holocene. Quaternary International 150, (2006). 7181.CrossRefGoogle Scholar
Maurizot, P., (2000). Carte géologique du sud-ouest Cameroun. Échelle 1:500 000. BRGM, Orléans Cedex 2.Google Scholar
Mercader, J., Runge, F., Vrydaghs, L., Doutrelepont, H., Ewango, C.E.N., and Juan-Tresseras, J. Phytoliths from archaeological sites in the tropical forest of Ituri, Democratic Republic of Congo. Quaternary Research 54, (2000). 102112.CrossRefGoogle Scholar
Mercader, J., Astudillo, F., Barkworth, M., Bennett, T., Esselmont, C., Kinyanjui, R., Grossman, D.L., Simpson, S., and Walde, D. Poaceae phytoliths from the Nyassa Rift, Mozambique. Journal of Archaeological Science 37, (2010). 19531967.CrossRefGoogle Scholar
Mworia-Maitima, J. Prehistoric fires and land-cover change in western Kenya: evidences from pollen, charcoal, grass cuticles and grass phytoliths. The Holocene 7, 4 (1997). 409417.CrossRefGoogle Scholar
Nangue, M.J. The seismicity of Cameroon. Sciences et Developpement 5, (2007). 2425.Google Scholar
Nanson, G.C., and Croke, J.C. A genetic classification of floodplains. Geomorphology 4, (1992). 459486.CrossRefGoogle Scholar
Neumann, K., Fahmy, A., Lespez, L., Ballouche, A., and Huysecom, E. The early Holocene palaeoenvironment of Ounjougou (Mali): phytoliths in a multiproxy context. Palaeogeography, Palaeoclimatology, Palaeoecology 276, (2009). 87106.CrossRefGoogle Scholar
Nfomou, N., Tongwa, A.F., Ubangoh, R., Bekoa, A., Metuk, N.J., and Victor, H.J. The July 2002 earthquake in the Kribi region: geological context and a preliminary evaluation of seismic risk in southwestern Cameroon. Journal of African Earth Sciences 40, (2004). 163172.CrossRefGoogle Scholar
Ngako, V. Carte de Géologie, ressources minières. Yahmed, D.B. Atlas du Cameroun. (2006). Les Éditions J.A., Paris. 6061.Google Scholar
Ngako, V., Affaton, P., Nnange, J.M., and Njanko, Th. Pan-African tectonic evolution in central and southern Cameroon: transpression and transtension during sinistral shear movements. Journal of African Earth Sciences 36, (2003). 207214.CrossRefGoogle Scholar
Ngomanda, A., Neumann, K., Schweizer, A., and Maley, J. Seasonality change and the third millennium BP rainforest crisis in Central Africa: a high resolution pollen profile from Nyabessan, southern Cameroon. Quaternary Research 71, (2009). 307318.CrossRefGoogle Scholar
Olivry, J.C. Fleuves et rivières du Cameroun. (1986). ORSTOM, Paris. 1733.Google Scholar
Parr, J.F. Effect of fire on phytolith coloration. Geoarchaeology 21, 2 (2006). 171185.CrossRefGoogle Scholar
Pastouret, L., Chamley, H., Delibrias, G., Duplessy, J.C., and Theide, J. Late Quaternary climatic changes in Western Tropical Africa deduced from deep-sea sedimentation off the Niger Delta. Oceanologica Acta 1, (1978). 217232.Google Scholar
Penney, J.T., and Racek, A.A. Comprehensive revision of a worldwide collection of freshwater sponges (Porifera: Spongillidae). U.S. National Museum Bulletin 272, (1968). Smithsonian Institution, Washington D.C..Google Scholar
Piperno, D. Phytolith Analysis: An Archaeological and Geological Perspective. (1988). Academic Press, San Diego.Google Scholar
Piperno, D. Phytoliths: A Comprehensive Guide for Archaeologists and Paleogeologists. (2006). Altamira Press, New York.Google Scholar
Piperno, D., and Becker, P. Vegetational history of a site in the Central Amazon Basin derived from phytolith and charcoal records from natural soils. Quaternary Research 45, (1996). 202209.CrossRefGoogle Scholar
Preuss, J. Jungpleistozäne Klimaänderungen im Kongo-Zaire-Becken. Geowissenschaften in Unserer Zeit 4, (1986). 177187.Google Scholar
Raunet, M. Les bas-fonds en Afrique et à Madagascar. Zeitschrift für Geomorphologie N.F., Supplementband 52, (1985). 2562.Google Scholar
Robert, Ch. Clay mineral associations and structural evolution of the South Atlantic. Proceedings of the 24th International Geology Congress Montreal 7, (1987). 316323.Google Scholar
Runge, F. Opalphytolithe in Pflanzen aus dem humiden und semi-ariden Osten Afrikas und ihre Bedeutung für die Klima- und Vegetationsgeschichte. Botanische Jahrbücher für Systematik 118, (1996). 303363.Google Scholar
Runge, F. The opal phytolith inventory of soils in central Africa—quantities, shapes, classification and spectra. Review of Palaeobotany and Palynology 107, (1999). 2353.CrossRefGoogle Scholar
Runge, F. Opal-Phytolithe in den Tropen Afrikas und ihre Verwendung bei der Rekonstruktion paläoökologischer Umweltverhältnisse. (2000). Books on Demand, Paderborn, Germany.Google Scholar
Runge, J., Eisenberg, J., and Sangen, M. Geomorphic evolution of the Ntem alluvial basin and physiogeographic evidence for Holocene environmental changes in the rain forest of SW Cameroon (Central Africa)—preliminary results. Zeitschrift für Geomorphologie N.F., Supplementband 145, (2006). 6379.Google Scholar
Sangen, M. New evidence on palaeoenvironmental conditions in SW Cameroon since the Late Pleistocene derived from alluvial sediments of the Ntem River. Palaeoecology of Africa 28, (2008). 79101.Google Scholar
Sangen, M., (2009). Physiogeographische Untersuchungen zur pleistozänen und holozänen Umweltgeschichte an Alluvionen des Ntem-Binnendeltas und alluvialer Sedimente der Flüsse Boumba, Ngoko, Nyong und Sanaga in Süd-Kamerun. PhD-thesis, J.W. Goethe-University Frankfurt, 1343.Google Scholar
Sangen, M. New results on palaeoenvironmental conditions in equatorial Africa derived from alluvial sediments of Cameroonian rivers. Proceedings of the Geologists' Association 122, (2011). 212223.CrossRefGoogle Scholar
Sangen, M., Eisenberg, J., Kankeu, B., Runge, J., and Tchindjang, M. New findings from geological, geomorphological and sedimentological studies on the palaeoenvironmental conditions in southern Cameroon. Palaeoecology of Africa 30, (2010). 165188.Google Scholar
Schefuß, E., Schouten, S., and Schneider, R.R. Climatic controls on central African hydrology during the past 20,000 years. Nature 437, (2005). 10031006.CrossRefGoogle ScholarPubMed
Schneider, R.R., Price, B., Müller, P.J., Kroon, D., and Alexander, I. Monsoon related variations in Zaire (Congo) sediment load and influence of fluvial silicate supply on marine productivity in the east equatorial Atlantic during the last 200,000 years. Paleoceanography 12, (1997). 463481.CrossRefGoogle Scholar
Schwandes, L.P., and Collins, M.E. Distribution and significance of freshwater sponge spicules in selected Florida soils. Transactions of the American Microscopical Society 113, 3 (1994). 242257.CrossRefGoogle Scholar
Scott, L. Grassland development under glacial and interglacial conditions in southern Africa: review of pollen, phytolith and isotope evidence. Palaeogeography, Palaeoclimatology, Palaeoecology 177, (2002). 4757.CrossRefGoogle Scholar
Ségalen, P. Les sols et géomorphologie du Cameroun. Cahiers ORSTOM 1, (1967). 137187.Google Scholar
Shanahan, T.M., Overpeck, J.T., Wheeler, C.W., Beck, J.W., Pigati, J.S., Talbot, M.R., Scholz, C.A., Peck, J., and King, J.W. Paleoclimatic variations in West Africa from a record of Late Pleistocene and Holocene lake level stands of Lake Bosumtwi, Ghana. Palaeogeography, Palaeoclimatology, Palaeoecology 242, (2006). 287302.CrossRefGoogle Scholar
Strömberg, C.A.E. Using phytolith assemblages to reconstruct the origin and spread of grass-dominated habitats in the Great Plains during the late Eocene to early Miocene. Palaeogeography, Palaeoclimatology, Palaeoecology 207, 3–4 (2004). 239275.CrossRefGoogle Scholar
Strömberg, C.A.E. Methodological concerns for analysis of phytolith assemblages: does count size matter?. Quaternary International 193, (2009). 124140.CrossRefGoogle Scholar
Tchouto, M.G.P., (2004). Plant diversity in a tropical rain forest. Implications for biodiversity and conservation in Cameroon. PhD-thesis, University of Wageningen, .Google Scholar
Thomas, M.F. Late Quaternary environmental changes and the alluvial record in humid tropical environments. Quaternary International 72, (2000). 2336.CrossRefGoogle Scholar
Thomas, M.F. Understanding the impacts of Late Quaternary climate change in the tropical and sub-tropical regions. Geomorphology 101, (2008). 146158.CrossRefGoogle Scholar
Thomas, M.F., and Thorp, M.B. Geomorphic response to rapid climatic and hydrologic change during the late Pleistocene and early Holocene in the humid and sub-humid tropics. Quaternary Science Reviews 14, (1995). 193207.CrossRefGoogle Scholar
Thomas, M.F., and Thorp, M.B. Palaeohydrological reconstruction for tropical Africa since the Last Glacial Maximum—evidence and problems. Benito, G., and Gregory, K.J. Palaeohydrology: Understanding Global Change. (2003). Wiley, Chichester. 167192.Google Scholar
Toteu, S.F., Penaye, J., and Poudjoum Djomeni, Y. Geodynamic evolution of the Pan-African belt in central Africa with special reference to Cameroon. Canadian Journal of Earth Sciences 41, (2004). 7385.CrossRefGoogle Scholar
TREES Tropical Ecosystem Environment Observation by Satellites (TREES). Vegetation Map of Central Africa. (1997). World Resources Institute, Ispra. http://www.global-forestwatch.org/english/datawarehouse/index.asp# Google Scholar
Vandenberghe, J. Climate forcing of fluvial system development: an evolution of ideas. Quaternary Science Reviews 22, (2003). 20532060.CrossRefGoogle Scholar
Villiers, J.F. La végétation. Santoir, C., and Bopta, A. Atlas régional Sud-Cameroun. (1995). Éditions ORSTOM, Paris. 1011.Google Scholar
Weldeab, S., Lea, D.W., Schneider, R.R., and Andersen, N. 155,000 years of West African monsoon ocean thermal evolution. Science 316, (2007). 13031307.CrossRefGoogle Scholar
Zabel, M., Schneider, R., Wagner, T., Adegbie, A.T., De Vries, U., and Kolonic, S. Late Quaternary climate changes in Central Africa as inferred from terrigenous input in the Niger Fan. Quaternary Research 56, (2001). 207217.CrossRefGoogle Scholar
Zucol, A.F., Brea, M., and Scopel, A. First record of fossil wood and phytolith assemblages of the late Pleistocene in El-Palmer National Park (Argentina). Journal of South American Earth Sciences 20, (2005). 3343.CrossRefGoogle Scholar