Journal of Geosciences and Geomatics
ISSN (Print): 2373-6690 ISSN (Online): 2373-6704 Website: http://www.sciepub.com/journal/jgg Editor-in-chief: Maria TSAKIRI
Open Access
Journal Browser
Go
Journal of Geosciences and Geomatics. 2019, 7(5), 221-236
DOI: 10.12691/jgg-7-5-2
Open AccessArticle

Petrography and Geochemistry of the Somie-Ntem Granitoids (Western Cameroon-Domain): Implication on the Pan-African Evolution of the Central African Fold Belt

Mero Yannah1, 2, , Juliana Amboh Tifang2, Eric Martial Fozing1, Yaya Fodoué3, Armand Dongmo Kagou1 and Samuel Ndonyui Ayonghe4

1Department of Earth Sciences, University of Dschang, Dschang, Cameroon

2Remote Sensing Unit, Institute of Geological and Mining Research, Yaounde, Cameroon

3Research Center for Geology and Mining, Institute of Geological and Mining Research, Garoua, Cameroon

4Central Unit for Internal Control and Evaluation, University of Buea, Buea, Cameroon

Pub. Date: November 24, 2019

Cite this paper:
Mero Yannah, Juliana Amboh Tifang, Eric Martial Fozing, Yaya Fodoué, Armand Dongmo Kagou and Samuel Ndonyui Ayonghe. Petrography and Geochemistry of the Somie-Ntem Granitoids (Western Cameroon-Domain): Implication on the Pan-African Evolution of the Central African Fold Belt. Journal of Geosciences and Geomatics. 2019; 7(5):221-236. doi: 10.12691/jgg-7-5-2

Abstract

Somie-Ntem area within the Tikar plain form part of the Western Cameroon Domain (WCD) that belong to the Central African Pan-African Fold Belt (CAPFB). Petrography and whole rock geochemistry characterize the granitoids of this area into granites (Gr), granodiorites (GD) and tonalite (Tn) forming group I granitoids. These rocks displaying high-calc-alkaline to shoshonite affinity and strongly metaluminous I-type. They also show strong enrichment in Ba-Sr and no pronounced Euanomaly, belongs to syn-to post collisional tectonic setting. Group II rocks consist of AGr show strange characteristics with high K-calc-alkaline affinity, metaluminous and peraluminous of I-type, and also very poor in Ba-Sr, strong negative Eu anomaly typical of post orogenic. Both groups depleted in Nb, Th, Ti with Pb and Dy enrichment. However, the Al2O3/TiO2vs TiO2Harker plot show that the group I granitoids originated from a common melt and got differentiated through fractional crystallization during syn-to-post tectonic regime at subduction environment induced by a crustal thickening tectonic regime. Group II granitoids are post orogenic, emplaced following tectonic extension at subduction leading to the injection of strongly evolved magma from partial melting of new material at the lower crust.

Keywords:
granitoids petrography geochemistry somie-ntem tikar plain pan-african cameroon

Creative CommonsThis work is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

References:

[1]  KouankapNono G. D., 1, Nzenti J. P. and Suh C. E. and Ganno S. (2010). Geochemistry of Ferriferous, High-K Calc-Alkaline Granitoids from the Banefo-MvoutsahaMassif (NE Bafoussam), Central Domain of the Pan-African Fold Belt, Cameroon. The Open Geological Journal, 4: 15-28.
 
[2]  Ngako V., Jegouzo P. and Nzenti J. P. (1991). Le Cisaillement Centre Camerounais. Roˆ le structural et géodynamique dans l’orogenèse pan-africaine. Comptesrendus De l’Académie des Sciences Paris, 315: 457-463.
 
[3]  Bella Nké B. E., Njanko T., Mamtani M. A., Njonfang E. and Rochette P. (2018). Kinematic evolution of the Mbakop Pan-African granitoids (western Cameroon domain): An integrated AMS and EBSD approach. Journal of Structural Geology, 111: 42-63.
 
[4]  Toteu S. F., Van Schmus W. R., Penaye J. and Michard A. (2001). New U–Pb and Sm–Nd data from north-central Cameroon and the pre-Pan African history of central Africa. Precambrian Research, 108: 45-73.
 
[5]  Njonfang E., Tchoneng G. T., Cozzupoli D. and Lucci F: (2013). Petrogenesis of the Sabongari alkaline complex, Cameroon line (central Africa): Preliminary petrological geochemical constraints. Journal of African Earth Sciences, 83: 25-50.
 
[6]  Lasserre M. (1967). Données géochronologiques nouvelles acquises au 1er janvier 1967 par la méthode au strontium appliquée aux formations cristallines et cristallophylliennes au Cameroun. Ann Faculté de Science Université Clermont-Ferrand Géologie et Minéral, 36: 109-144.
 
[7]  Tchameni R., Sun F., Dawaï D., Danra G. Tékoum L. NomoNegue E., Vanderhaeghe O. and Nzolang C. (2016). NguihdamaDagwaï-Zircon dating and mineralogy of the Mokong Pan-African magmatic epidote-bearing granite (North Cameroon). International Journal of Earth Sciences (GeolRundsch), 105: 1811-1830.
 
[8]  Lasserre M., Tempier P. and Soba D. (1981). Petrographie et geochronologie Rb/Sr des granites cambriens de Goutchoumi et d’Anloa (Cameroun). Bulletin de SociétéGéologique de la France 23: 511-514.
 
[9]  Soba D., Michard A., Toteu S. F., Norman D. I., Penaye J., Ngako V., Nzenti J. P. and Dautel, D. (1991). Données géochronologiques nouvelles (Rb-Sr, U-Pb et Sm- Nd) sur la zone mobile panafricaine de l’Est-Cameroun: âge Protérozoïque supérieur de la série de Lom. ComptesRendusAcadémie Sciences Paris, 312: 1453-1458.
 
[10]  Tchouankoue J. P. (1992). La syénite de Bangangté: un complexe panafricain à caractères in termediaires. Pétrologie-Géochimie. Thèse Doctorat 3è cycle, Université de Yaoundé I. p 160.
 
[11]  Nguiessi T. C., Nzenti J. P., Nsifa E. N., Tempier P., Tchoua F.M. (1997). Les granitoïdes calco-alcalins, syncisaillement de Bandja dans la chaîne panafricaine nord-équatoriale au Cameroun. C. R. Academic of Sciences Paris, 325: 95-101.
 
[12]  Tagne-Kamga G. (2003). Petrogenesis of the Neoproterozoic Ngondo plutonic complex (Cameroon, west central Africa): a case of late-collisional ferro-potassicmagmatism. Journal of African Earth Sciences, 36: 149-171.
 
[13]  Nzolang C., Kagami H., Nzenti J. P., Holtz F. (2003). Geochemistry and preliminary Sr-Nd isotopic data on the Neoproterozoic granitoids from the Bantoum area, West Cameroon: evidence for a derivation from a Paleoproterozoic Archean crust. Polar Geosciences, 16: 196-226.
 
[14]  Tetsopgang S. (2003). Petrology, geochemistry and geochronology of Pan-African granitoids in the Nkambé area, Northwestern Cameroon, Africa. PhD Thesis, Nagoya University, Japan.
 
[15]  Djouka-Fonkwé M. L., Schulz B., Schüssler U., Tchouankoué J. P. and Nzolang C. (2008). Geochemistry of the Bafoussam Pan-African I and S- type granitoids in western Cameroon. Journal of African Earth Sciences, 50: 148-167.
 
[16]  Nzina A. C., Nzenti1 J. P., Njiosseu. E. L. T., Ganno S. and Ngnotue T. (2010). Synkinematicferro-potassicmagmatism from the Mekwene-NjimafofireFoumban Massif, along the Foumban-Banyo shear zone in central domain of Cameroon Pan-African fold belt. Journal of Geology and Mining Research. 2: 142-158.
 
[17]  Njonfang E. and Moreau M. (2000). The mafic mineralogy of the Pandé massif, Tikar plain, Cameroon: Implications for a peralkaline affinity and emplacement from highly evolved alkaline magma. Mineralogical Magazine, 64: 525-537.
 
[18]  Castaing C, Feybesse J. L., Thiéblemont D., Triboulet C. and Chèvremont P. (1994). Palaeogeographical reconstructions of the Pan-African/Brasilianoorogen: closure of an oceanic domain or intracontinental convergence between major blocks? Precambian Research, 69: 327-344.
 
[19]  Toteu S. F., Penaye J. and PoudjomDjomani Y. (2004). Geodynamic evolution of the Pan-African belt in central Africa with special reference to Cameroon. Canadian Journal of Earth Sciences, 41: 73-85.
 
[20]  Tchameni R., Pouclet A., Penaye J., Ganwa A. A. and Toteu S. F. (2006). Petrography and geochemistry of the Ngaoundéré Pan-African granitoids in Central North Cameroon: Implications for their sources and geological setting. Journal of African Earth Sciences, 44: 543-560.
 
[21]  Djouka-Fonkwe´ M. L. (2005). Association of S-type and I-type granitoids in the Neoproterozoic Cameroon orogenic belt, Bafoussam area, west Cameroon: geology, geochemistry and petrogenesis. Unpublished PhD Thesis, University of Wu¨rzburg, Germany, p197.
 
[22]  Abdelsalam M. G., Liégeois J. P. and Stern R. J. (2002). The Saharan meta-craton. Journal of African Earth Sciences, 34: 119-136.
 
[23]  Affaton P. (1990). Le bassin des Volta (Afrique de l’Ouest) : une marge passive d’âge protérozoïque supérieur, tectonisée au panafricain (600 ± 50 Ma). Etudes etThèses ORSTOM, Paris, France.
 
[24]  Caby R. and Boessé J. M. (2001). Pan-African nappe system in southwest Nigeria: the Ife-Ilesha schist belt. Journal of African Earth Sciences, 33: 211-225.
 
[25]  Nguiessi-Tchankam C. and Vialette, Y. (1994). Donne´esge´ochronologiques (Rb-Sr, Pb-Pb, U-Pb) sur le complexe plutonique de Bandja (Centre Ouest Cameroun). ComptesRendus de l’Acade´mie des Sciences Paris, 319: 317-324.
 
[26]  Jacquemin H., Sheppard S. M. F. and Vidal P. (1982). Isotopic geochemistry (O, Sr, Pb) of the Golda Zuelva and Mboutouanorogenic complexes, North Cameroon: mantle origin with evidence of crustal contamination. Earth and Planetary Science Letters, 61: 97-111.
 
[27]  Parsons I., Brown W. L. and Jacquemin H. (1986). Mineral chemistry and crystallization conditions of the Mboutou layered gabbro-syenite-granite complex, North Cameroon. Journal of Petrology, 27: 1305-1329.
 
[28]  Ngounouno I., Moreau C., Déruelle B., Demaiffe D. and Montigny R. (2001). Pétrologie du complexe alcalin sous-saturé de Kokoumi (Cameroun). Bulletin de la SociétéGéologique de France 172: 675-686.
 
[29]  Bella Nké B. E., Njanko T., Kwékam M., Njonfang E., Naba S., Tcheumenak K. J., Gountié M., Rochette P. and Nédélec A. (2014). Structural study of the Foréké-Dschang trachytic dome (Mount Bambouto, West Cameroon): An anisotropy of magnetic susceptibility (AMS) approach. Journal of African Earth Sciences, 95: 63-76.
 
[30]  Njonfang E., Nono A., Kamgang P., Ngako v. and Tchoua F. M. (2011). Cameroon line alkaline magmatism (Central Afirca): A reappraisal. The geological Society of America, 478: 173-191.
 
[31]  Njonfang E., Moreau C. and Tchoua F. M. (1998). La bande mylonitique Foumban - Bankim, Ouest Cameroun. Une zone de cisaillement de haute température. C. R. Academic Science. Paris327: 735-741.
 
[32]  Njonfang E., Ngako V., Kwékam M. and Affaton P. (2006). Les orthogneisscalco-alcalins de Foumban-Bankim: témoins d’une zone interne de marge active panafricaine en cisaillement. C. R. Geosciences. 338: 606-616.
 
[33]  De La Roche H., Leterrier J., Grandclaude P. and Marchal, M. (1980). A classification of volcanic and plutonic rocks using R1R2-diagram and major element analyses, its relationships with current nomenclature. Chemical Geology 29, 183-210.
 
[34]  McDonough W. F. and Sun S. S. (1995). The composition of the Earth. Chemical Geology, 120: 223-253.
 
[35]  Sun S. S. and McDonough W. F. (1989): Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders, A. D., M.. J.(Eds.), Magmatism in ocean basins, vol. 42. Geological Society of London Special Publication, p 429-448
 
[36]  Frost B. R., Barnes C. G., Collins W. J., Arculus R. J., Ellis D. J. and Frost C. D. (2001). A geochemical classification for granitic rocks. Journal of Petrology. 42: 2033-2048.
 
[37]  Peccerillo A. and Taylor, S. R. (1976). Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, Northern Turkey. Contributions to Mineralogy and Petrology, 58: 63-81.
 
[38]  Le Marechal A. (1975). Carte géologique de l’Ouest du Cameroun et de l’Adamaoua. Office de la Recherche Scientifique et Technique Outre-Mer (ORSTOM), Service Central de documentation, 70-74, Route d’Aulnay-93 Bondy France.
 
[39]  Imeokparia E. G. (1981). Ba/Rb and Rb/Sr ratios as indicators of magmatic fractionation, postmagmatic alteration and mineralization Afu Younger Granite Complex, Northern Nigeria. Geochemical Journal, 15: 209-219.
 
[40]  Hassanen M. A., Egnisr S. A. and Mohamed F. H. (1996). Geocheinistry and petrogenesis of Pan-African I-type granitoids at GabalIglaAhmar, Eastern Desert, Egypt. Journal of African Earth Sciences, 22: 29-42.
 
[41]  Kwékam M., Hartmann G., Njanko T., Tcheumenak K. J., Fozing E. M., Njonfang E. (2015). Geochemical and Isotope Sr-Nd Character of Dschang Biotite Granite: Implications for the Pan-African Continental Crust Evolution in West-Cameroon (Central Africa). Earth Science Research; 4: 88-102.
 
[42]  Martin H. (1987): Petrogenesis of Archaeantrondhjemites, tonalites, and granodiorites from eastern Finland: major and trace element geochemistry. Journal of Petrology, 28: 921-953.
 
[43]  Sun S. S. and Nesbitt R. W. (1978): Geochemical irregularities and genetic significance of ophiolitic basalts. Geology, 6: 689-693.
 
[44]  Wilson, M., (1989): Igneous Petrogenesis. Unwin Hyman, London.
 
[45]  Hanson G. N. (1978): The application of trace elements to the petrogenesis of igneous rocks of granitic composition. Earth and Planetary Science Letters, 38: 26-43.
 
[46]  Nascimento R. S. C., Mcreath I. and Galindo A, C. (2010). Relationships between Shearing and Granitic Magma Emplacement: the Remígio-Pocinhos Shear Zone in the São José do Campestre Massif, NE Brazil. Geologia USP-SerieCientifica, 3: 3-18.
 
[47]  Janoušek V. Bowes D. R., Rogers G., Farrow C. M and Jelinek E. (2000): Modelling diverse processes in the petrogenesis of a composite batholith: the Central Bohemian Pluton, Central European Hercynides. Journal of Petrology, 41: 511-543.
 
[48]  Motoki A., Sichel S. E., Vargas T., Melo D. P. and Motoki K. F. (2015): Geochemical behaviour of trace elements during fractional crystallization and crustal assimilation of the felsic alkaline magmas of the state of Rio de Janeiro, Brazil. Anais da Academia Brasileira de Ciências, 87: 1959-1979.
 
[49]  Rollinson H. R. (1993). Using geochemical data: evaluation, presentation, interpretation: Longman Group, p352.
 
[50]  Roberts M. P. and Clemens J. D. (1993). “Origin of high-potassium, calcalkaline, I-type granitoids”. Geology, 21: 825-828.
 
[51]  Térakado Y. and Masuda A. (1988). Trace element variations in acidic rocks from the inner zone of southwest Japan. Chemical Geology, 67: 227-241.
 
[52]  El-Afandy A. H., AlrahmanEmbaby A. B. D. and. El Harairey M. A. (2015). Geology, geochemistry and radioactivity of granitoid rocks of Abu Marw area, South Eastern Desert, Egypt. Nuclear Sciences Scientific Journal, 4: 61-83.
 
[53]  Liégeois J. P., Navez J., Hertogen J. and Black R. (1998). Contrasting origin of post-collisional high-K calc-alkaline and shoshonitic versus alkaline and peralkaline granitoids: the use of sliding normalization. Lithos, 45: 1-28.
 
[54]  KouankapNono G. D., Wotchoko P., Magha A., Ganno S., Njoya N., Ngambu A. A., Jean Paul Nzenti J. P. and Kabeyene V. K. (2018). Contrasting Ba-Sr Granitoids from Bamenda Area, NW Cameroon: Sources Characteristics and Implications for the Evolution of the Pan African Fold Belt. Journal of Geosciences and Geomatics, 6: 65-76.
 
[55]  Pearce J. A., Harris N. B. W., and Tindle A.G. (1984). “Trace elements discrimination diagrams for the geotectonic interpretation of granite rocks”. Journal of Petrology, 25: 956-983.
 
[56]  El Baghdadi M., El Boukhari A., Jouider A., Benyoucef A. and Nadem S. (2003). Calc-alkaline Arc I-type Granitoid Associated with S-type Granite in the Pan-African Belt of Eastern Anti-Atlas (Saghro and Ougnat, South Morocco). Gondwana Research, 6: 557-572.
 
[57]  Asran M. A. and Ezzat M. R. (2012). The Pan-African calc-alkaline granitoids and the associated mafic microgranular enclaves (MME) around the Wadi Abu Zawal North Eastern Desert, Egypt: Geology, Geochemistry and Pretrogenesis. Journal of Biology and Earth Sciences, 2: 1-16.
 
[58]  Harlov D. E. and Austrheim H. (2013). Metasomatism and the Chemical Transformation of Rock: Rock-Mineral-Fluid Interaction in Terrestrial and Extraterrestrial Environments, Earth System Sciences, p16.
 
[59]  Batchelor R. A. and Bowden P. (1985). Petrogenetic interpretation of granitoid rocks series using multicationic parameters. Chemical Geology 48: 43-55.
 
[60]  Nabelek P. I. and Liu M. (2004). Petrologic and thermal constraints on the origin of leucogranites in collisional orogens. Earth and Environmental Science and environment Transactions of the Royal Society of Edinburgh, 95: 73-85.
 
[61]  Karimpour M. H. and Bowes W. W. (1983): Application of trace elemnts and isotopes for discriminatig between porphyry molybdenum, copper, and tin systems and the implications for predicting the grade: Global Tectonics and Metallogeny, 2: 29-36.
 
[62]  Barker S. D. (2007). Compositions of granophyre, myrmekite and graphic granite: Geological Society of America Bulletin, 81: 3339-3350.
 
[63]  Fozing E. M., Kwékam M., Njanko T., Njonfang E., Séta N., Yakeu S. A. F. and Sawadogo S. (2014): Structural evolution of the Pan-African Misajé pluton (Northwestern Cameroon). Syllabus Review, 5: 12-26.
 
[64]  Blevin P. (2003). Metallogeny of granitic rocks. In: Magmas to mineralization. Blevin P. et al. (eds). The Ishihara symposium: p1-4.
 
[65]  Chebeu C., Nlend C. D. N., Nzenti J. P. and Ganno S. (2011). Neoproterozoic high-K Calc-alkaline Granitoids from Bapa-Batié, North Equatorial Fold Belt, Central Cameroon: Petrogenesis and Geodynamic Significance. The Open Geology Journal, 5: 1-20.
 
[66]  Harrisson T. M., Grove M., McKeegan K. D., Coath C. D., Lovera O. M and Le Fort P. (1999). “Origin and episodic emplacement of the Manaslu intrusive complex, central Himalaya”, Journal of. Petrology, 40: 3-19.
 
[67]  El-Mettwaly A. A., Zalata A. A. and Abu El-Enen M. M. (1992). The evolution of the Pan-African granitoid rocks: geochemical evidences from SW Sinai massif, Egypt. Journal of African Earth Sciences(and the Middle East), 14: 111-119.
 
[68]  Eby N. (2014). A-type granites: characteristics, petrogenesis and their contribution to the growth of the continental crust. University of Massachusetts, Lowell, MA 01854, USA.
 
[69]  Toteu S. F., Macaudière J., Bertrand J. M., Dautel D. (1999). Metamorphic zircon from North Cameroon; implications for the Pan-African evolution of central Africa. GeologischeRundschau, 79: 777-788.
 
[70]  Gehad M. S. (2000). Pan-African Younger Granitoids of the Southern Eastern Desert, Egypt: Geology, Geochemical Constraints, and Mineralization. International Geology Review, 48: 360-381.
 
[71]  Toteu S. F. (1990): Geochemical characterization of the main petrographycal and structural units of northern Cameroon: implications for Pan-African evolution. Journal of African Earth Sciiences, 10: 615-624.
 
[72]  Ngako V., Affaton P., Nnange J. M. &Njanko T. H. (2003). Pan-African tectonic evolution in the central and southern Cameroon: trans-pression and trans-tension during sinistral shear movements. Journal of African Earth Sciences, 36: 207-214.
 
[73]  TchaptchetTchato D., Nzenti J. P., Njiosseu E. L., Ngnotue, T. and Ganno S. (2009). (Neoproterozoic metamorphic events in the Kekem area Central Domain of the Cameroon north equatorial fold belt): P-T data. Journal of the Cameroon Academy of Sciences, 8: 91-106.
 
[74]  Chappell B.W. and White A. J. R. (1992). I and S-type granites in the Lachlan Fold Belt. Transactions of the Royal Society of Edinburgh: Earth Sciences 83: 1-26.
 
[75]  Noble D. C., Haffty J. and Hedge C. E. (1969). Strontium and magnesium contents of some natural peralkaline silicic glasses and their petrogenetic significance. American Journal of Science, 267: 598-608.
 
[76]  Rogers J. J. W. and Greengerg J. K. (1990): Late-orogenic, post-orogenic and anorogenic granites: Distinction by major element and trace element chemistry and possible origin. Jornal of Geology, 98: 291-309.