Volume 4, Issue 6, December 2015, Page: 266-274
Petrographic and Geochemical Characterization of Basalts in Bangangte Area (West Cameroon): Implications on Their Source
Pierre Wotchoko, Department of Geology, Higher Teacher Training College, University of Bamenda, Bambili, Bamenda, Cameroon
Joëlle Flore Tene Djoukam, Department of Earth Sciences, Faculty of Sciences, University of Yaoundé 1, Yaoundé, Cameroon
Gus Djibril Kouankap Nono, Department of Geology, Higher Teacher Training College, University of Bamenda, Bambili, Bamenda, Cameroon
Patrice Arnaud Kouske, Institute of Technology, University of Douala, Douala, Cameroon
David Guymollaire Nkouathio, Department of Earth Sciences, Faculty of Sciences, University of Dschang, Dschang, Cameroon
Solange Atenkia Fonkem, Department of Geology, Higher Teacher Training College, University of Bamenda, Bambili, Bamenda, Cameroon
Received: Oct. 25, 2015;       Accepted: Nov. 6, 2015;       Published: Dec. 7, 2015
DOI: 10.11648/j.earth.20150406.18      View  3590      Downloads  86
Abstract
The Bangangte area belongs to the Cameroon Volcanic Line. The volcanic rocks exposure in the area consist of fine microlitic porphiritic Basalts which still poorly surveyed. Petrographically, the studied rocks are made up of minerals like plagioclase, clinopyroxene, olivine phenocrysts and a lot of opaque minerals within a very fine grained matrice. The Bangangte basalts are quartz normative free and are olivine, Diopside, Hypersthene normative. Alkaline (Na2O + K2O) contents vary from 2.247% to 5.46%. These rocks are low-Mg basalts with the Mg# values vary from 42.86 to 45.95 which are characteristic of primitive mantle source. The studied rocks are alkali to transitional basalts with Nb/Y ratio>1.5. Chondrite normalized spider diagram pattern of REE shows uniform patterns with enrichment in LREE and a relative depletion in HREE. While MORB normalized spider diagram pattern of multi elements reveals a negative anomaly with K2O, with enrichement in LILE and depletion in HREE. The Eu anomalies are positive to nulle and are typical of alkali basalts. The Bangangté transitional alkali basalts were formed in intraplate setting of continental part of the CVL. They are the products of partial melting of about 13% of an asthenosphere made up of garnet peridotite. Geochemically, the studied basalts are similar to alkali basalts from Mount Bamenda.
Keywords
Bangangte, CVL, Alkali to Transitional Basalts, Asthenosphere, Garnet Peridotite
To cite this article
Pierre Wotchoko, Joëlle Flore Tene Djoukam, Gus Djibril Kouankap Nono, Patrice Arnaud Kouske, David Guymollaire Nkouathio, Solange Atenkia Fonkem, Petrographic and Geochemical Characterization of Basalts in Bangangte Area (West Cameroon): Implications on Their Source, Earth Sciences. Vol. 4, No. 6, 2015, pp. 266-274. doi: 10.11648/j.earth.20150406.18
Copyright
Copyright © 2015 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Reference
[1]
Gountie D. M., Nono A., Njonfang E., Kamgang P., Zangmo T. G., Kagou D. A., Nkouathio D. G., 2009. Le volcanisme ignimbritique des monts Bambouto et Bamenda (Ligne du Cameroun, Afrique Centrale): Signification dans la formation des caldeiras. Bulletin de l’institut scientifique. 2011, n°33, P. 1-15.
[2]
Fitton J.G., 1983 “Active versus Rifting: Evidence from the west Africa,’’Tectonophysics, Vol.94, No.1-4, pp.473-481.
[3]
Njonfang E., 1998, “Contribution à L’étude de la Relation entre la ‘Ligne du Cameroun’ et la Direction de l’Adamawa: 1- Pétrologie, Géochimie et Structure des Granitoid africains de la Zone de Cisaillement Foumban- (Ouest-Cameroun et Adamawa). 2-Pétrologie et Géo- chimie des Formations Magmatiques Tertiaires Associées,” Thèse de Doctorat d’Etat, Université of Yaoundé I, Yaoundé, p. 379.
[4]
Moreau C., Regnoult J.M., Déruelle B., Robineau B., 1987. A new tectonic model for the Cameroon Line, Central Africa. Tectonophysics 139, 317–334.
[5]
Guiraud R. M., Binks C. S, Fairhe Szabo J. D., Fairhead and Wilson M., 1992 “Chronology and Geodynamic Set- ting of Cretaceous-Cenozoic Rifting in West and Central Africa,” Tectonophysics, Vol. 213, No. 1-2, pp.234.
[6]
Moundi A., 2004. Les basaltes des plateaux du plateau Bamoun: Pétrologie-géochimie et géochronologie. Implications sur les sources des magmas, contexte et évolution géodynamiques. The`se de Doctorat d’Etat, Université´ de Yaounde´ I, Cameroun, 208p.
[7]
Kuepouo, G., 2004. Geology, Petrology and Geochemistry of the Tertiary Bana Volcano–Plutonic Complex, Cameroon Line, Central Africa. Ph.D. Thesis, Kobe University, Japan, 301p.
[8]
Fosso J., Me´nard J.J., Bardinzeff J.M., Wandji P., Tchoua F.M., Bellon H., 2005. Les laves du mont Bangou: une première manifestation volcanique Eocène a affinité´ transitionnelle de la ligne de Cameroun. Comptes Rendus des Geosciences 337, 315–325.
[9]
Kamgang P., Chazot G., Njonfang E., Tchoua, F., 2008. Geochemistry and Geochronology of mafic rocks from Bamenda Mountains (Cameroon): Source composition and crustal contamination along the Camroon line. Comptes rendus Geoscience.
[10]
Ngounouno I., Deruelle B., Guiraud R., and Vicat J. P., 2001. Magmatismes tholéiitique et alcalin des demi-grabens crétacés de Mayo Oulo-Léré et de Babouri-Figuil (Nord du Cameroon-Sud du chad) en domaine d’extension continentale. Comptes rendus Academie des Sciences de Paris. 333 (2001) 201-207.
[11]
Kuepouo G., Tchouankoue JP., Nagao T., Sato H., 2006. Transitional tholeiitic basalts in the Tertiary Bana volcano-plutonic complex, Cameroon Line. J African Earth Science: 45: 318-32.
[12]
Best M.G., 2003. Igneous and Metamorphic Petrology. Blackwell Publishing. 2nd Edition. PP. 35-36.
[13]
Fitton J.G., 1987. The Cameroon Line, Africa: a comparison between Oceanic and continental alkaline volcanism. In: Fitton, J.G., Upton, B.G.J. (Eds.), Alkaline Igneous Rocks, Special Publication, vol. 30. Geological Society, London, pp. 273–291.
[14]
Lee D.C., Halliday A.N., Fitton J.C., Poli G., 1994. Isotopic variations with distance and time in the volcanic islands of the Cameroon line: evidence for the plume origin. Earth and Planetary Sciences Letters 123, 119–138.
[15]
Déruelle B., Moreau C., Nkoumbou C., Kambou R., Lissom J., Njonfang E., Nono A., 1991. The Cameroon Line: A Review. In: Kampunzu, A.B., Lubala, R.T. (Eds.), Magmatism in Extensional Tectonic Structural Settings. Springer, Berlin, pp. 274–327.
[16]
Déruelle B., Ngounouno I., and Demaiffe D., 2007. “The Cameroon Hot Line (CHL): A Unique Example of Active Alkaline Intraplate Structure in both Oceanic and Continental Lithospheres,” Comptes Rendus Geosciences 339, No. 9, pp. 589-600.
[17]
Moundi, A., Wandji, P., Bardintzeff, J.-M., Ménard, J.-J., Okomo Atouba, L.C., Mouncherou, O.F., Reusser, E., Bellon, H., Tchoua, F.M., 2007. Les basaltes éocènes à affinité transitionnelle du plateau Bamoun, témoins d’un réservoir mantellique enrichi sous la ligne volcanique du Cameroun. C.R. Geoscience 339, 396–406.
[18]
Suh C. E., Sparks R. S. J., Fitton J. G., Ayonghe S. N., Annen C., Nana R and Luckman A., 2003 “The 1999 and 2000 Eruptions of Mount Cameroon. Bulletin of Volcano. No. 4, pp. 267-281.
[19]
Lasserre M., 1978. Mise au point sur les granitoïdes dits ‘‘ultimes’’ du Cameroun. Gisement, petrographie et geochronologie. Bulletin du Bureau de Recherches Geologiques et Miniere 2, 145–159.
[20]
Njonfang E., Kamgang P., Ghogomu T.R., Tchoua F.M., 1992. The geochemical characteristics of some plutonic-volcanic complexes along the southern part of the Cameroon Line. Journal of African Earth Sciences 14, 255–266.
[21]
Nana J.M., 1988. Le complexe volcano-plutonique de Bana (Ouest Cameroun). Geologie et petrologie. These de Doctorat. Universite de Paris XI, France.
[22]
Ghogomu R.T., Moreau C., Brown W.L., Rocci G., 1989. The Ntumbaw complex, NW Cameroon: an atypical anorogenic ring complex of intermediate composition. Journal of African Earth Sciences 8, 1–9.
[23]
Halliday A.N., Dickin, Fallick A.P., Fitton J.G., 1988. Mantle dynamics: a Nd, Sr, Pb and O isotopic study of the Cameroon Line volcanic Chain. Journal of Petrology 29, 181–211.
[24]
Sato H., Aramaki S., Kusakabe M., Hirabayashi J.-I., Sano Y., Nojiri Y., Tchoua F., 1990. Geochemical difference of basalts between polygenetic and monogenetic volcanoes in the central part of the Cameroon volcanic line, Geochem. J. 24, 357–370.
[25]
Marzoli A., Renne P.R., Piccirillo E.M., Francesca C., Bellieni G., Melfi A.J., Nyobe J.B., N’ni J., 2000. The Cameroon Volcanic Line Revisited: Petrogenesis of continental basaltic magmas from lithospheric and asthenospheric mantle sources. Journal of Petrology 41, 87–109.
[26]
Fairhead J.D., Okereke C.S., 1987. A regional study of the West African Rift system in Nigeria and Cameroon and its tectonic interpretation. Tetctonophysics 143, 141–159.
[27]
Plomerova, J., Babuska, V., Dorbath, C., Dorbath, L., Lillie, R.J., 1993. Deep lithospheric structure across the Central African shear zone in Cameroon. Geophysical Journal International 115, 381–390.
[28]
Poudjom D.Y.H., Diament M., Wilson M., 1997. Lithospheric structure across the Adamawa plateau (Cameroon) from gravity studies. Tectonophysics 273, 317–327.
[29]
Ngako, V., Njonfang, E., Aka, F.T., Affaton, P., Nnange, J.M., 2006. The North-South paleozoic to Quaternary trend of alkaline magmatism from Niger-Nigeria to Cameroon: Complex interaction between hotspots and Precambrian faults. Journal of African Earth Sciences 45, 241-256.
[30]
Gountié D. M., Nédélec A., Nono A., Njanko T., Font E., Kamgang P., Njonfang E., Launeau P., 2011. Magnetic fabrics of the Miocene ignimbrites from West-Cameroon: Implications for pyroclastic flow source and sedimentation. Journal of Volcanology and Geothermal research 203 (2011) 113–132.
[31]
Cox K.G., Bell J. D., & Pankhurst R. J., 1979. The Interpretation of Igneous Rocks. George Allen & Unwin.
[32]
Middlemost E.A.K., 1975. The basalt clan, Earth Sci. Rev. 11 337–364.
[33]
Evensen N.M., Hamilton M.J., and Nions R.J.O., 1978. “Rare Earth Abundances in Chondritic Meteorites geochemica et Cosmochemica Acta, Vol. 42, pp. 1199- 1212.
[34]
Bevins R.E., Kokelaar B.P. and Dunkley P.N., 1984. Petrology and Geochemistry of lower to middle Ordovician Igneous rocks in Wales: a volcanic arc to marginal basin transition. Proc. Geol. Ass., 95, 337-347.
[35]
Xu H., Chen J., Lu Z., 2014. Geological and Geochemical characteristics of Basalts from Hardat Togoi mine, Inner Mongolia, China. Chinese Journal of Geochemistry, Springer Journals. 33 pp 145-154.
[36]
Thompson R.N and Morrison M.A., 1988. Asthenospheric and lower-lithospheric mantle contributions to continental extensional magmatism: an example from the British Tertiary Province: Chemical Geology. Volume 68, issues 1-2, 1988, pages 1-15.
[37]
Bogaard P.J.F., Wörner G, 2003. Petrogenesis of basanitic to tholeiiticvolcanic rocks from the Miocene Vogelsberg, Central Germany, J. Petrol.44. 569–602.
[38]
Déruelle B., Bardintzeff J.M., Cheminée J.L., Ngounouno I., Lissom J., Nkoumbou C., Etamé J., Hell J.V., Tanyileke G., N’ni J., Bekoa A., Ntepe N., Nono A., Wandji P., Fosso J., Nkouathio D.G. 2000. Éruptions simultanées de basalte alcalin et de hawaiite au mont Cameroun (28 mars–17 avril 1999), C. R.Acad. Sci.Paris, Ser. IIa 331. 525–531.
[39]
Yokoyama, T., Aka, F.T., Kusakabe, M., Nakamura, E., 2007. Plume–lithosphere interaction beneath Mt. Cameroon volcano, West Africa: constraints from 238U– 230Th–226Ra and Sr–Nd–Pb isotopic systematics. Geochimica et Cosmochimica Acta71, 1835–1854.
[40]
Pearce, J. A., Norry, M. J., 1979. Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks. Contributions to Mineralogy and Petrology69, pp. 33–47.
Browse journals by subject