Geochemical Characterizations of the Hypovolcanic Formations of the Pan-African Basement and the Cretaceous Sedimentary Basins of Figuil (North Cameroon) and Léré (South-West Chad): Petrogenetic and Geodynamic Implication of the Pan-African Range of Central Africa (CPAC)
The study area located between Figuil (Northern Cameroon) and Léré (Southwest Chad) belongs to the northern domain of the Pan-African Range of Central Africa (CPAC). The aim of this work is to highlight the petrogenesis of the hypovolcanic formations affecting the Pan-African base and the Cretaceous sedimentary basins of the study area as well as their geodynamic context. Hypovolcanic formations have a strong affinity with rocks of the continental tholeiitic series. The tholeiitic character with alkaline affinity constitutes the transition between alkaline and tholeiitic magmatisms. The low Rb/Sr ratios (0.24 - 1.24) constitute proof that the dolerites studied do not come from the partial fusion of Pan-African granitoids (Rb/Sr: 2.54 - 7.64) but rather from a mantle source as shown by the similar ratios of Zr/Hf (37.56 - 43.08), Nb/Ta (15.16 - 19.60) of dolerites from the Pan-African basement (DSP) and Zr/Hf (34.34 - 46.48), Nb/Ta (14.34 - 19.3) from dolerites from the Cretaceous sedimentary basins (DBSC). The enrichment in LREE relative to the HREE of the dolerites studied associated with the ratios (Tb/Yb)N (1.95 - 2.56), Dy/Yb (2.33 - 2.85) characterizes a mantle source of lherzolite with garnet.
References
[1]
Srivastava, R.K. (2011) Dyke Swarms: Keys for Geodynamic Interpretation. Springer.
[2]
Halls, H.C. (1987) Introduction. In: Halls, H.C. and Fahrig, W.F., Eds., Mafic Dyke Swarms, Geological Association of Canada, 1-3.
[3]
Bouyo, H.M., Zhao, Y, Penaye, J., Zhang, S.H. and Njel, U.O. (2015) Roches métavolcaniques et métasédimentaires liées à la subduction néoprotérozoïque de la ceinture de roches vertes de Rey Bouba au centre-nord du Cameroun en Afrique Centrale, Precambrien Research. Elsevier.
[4]
Maurin, J.-C. and Guiraud, R. (1990) Relationships between Tectonics and Sedimentation in the Barremo-Aptian Intracontinental Basins of Northern Cameroon. Journal of African Earth Sciences (and the Middle East), 10, 331-340. https://doi.org/10.1016/0899-5362(90)90064-l
[5]
Maurin, J. and Guiraud, R. (1993) Basement Control in the Development of the Early Cretaceous West and Central African Rift System. Tectonophysics, 228, 81-95. https://doi.org/10.1016/0040-1951(93)90215-6
[6]
Bessoles, B. and Trompette, R. (1980) La chaîne panafricaine. Zone mobile d’Afrique Centrale (partie sud) et zone soudanaise. Mémoire du Bureau de Recherches Géologiques etMinières, 92, 394.
[7]
Oliveira, E.P., Toteu, S.F., Araújo, M.N.C., Carvalho, M.J., Nascimento, R.S., Bueno, J.F., et al. (2006) Geologic Correlation between the Neoproterozoic Sergipano Belt (NE Brazil) and the Yaoundé Belt (Cameroon, Africa). Journal of African Earth Sciences, 44, 470-478. https://doi.org/10.1016/j.jafrearsci.2005.11.014
[8]
van Schmus, W.R., Oliveira, E.P., da Silva Filho, A.F., Toteu, S.F., Penaye, J. and Guimarães, I.P. (2008) Proterozoic Links between the Borborema Province, NE Brazil, and the Central African Fold Belt. Geological Society, London, Special Publications, 294, 69-99. https://doi.org/10.1144/sp294.5
[9]
Fosso Menkem, E. (2018) Tectonic-Sedimentary Evolution and Paleo-Environments of the Cretaceous Babouri-Figuil and Mayo-Oulo-Léré basins (North Cameroon). University of Yaoundé.
[10]
Penaye, J., Kröner, A., Toteu, S.F., Van Schmus, W.R. and Doumnang, J. (2006) Evolution of the Mayo Kebbi Region as Revealed by Zircon Dating: An Early (Ca. 740Ma) Pan-African Magmatic Arc in Southwestern Chad. Journal of African Earth Sciences, 44, 530-542. https://doi.org/10.1016/j.jafrearsci.2005.11.018
[11]
Kasser, M.Y. (1995) Precambrian Evolution of the Mayo-Kebbi Region. A Segment of the Pan-African Channel. Thesis National Museum of Natural History of Paris.
[12]
Dejax, J. and Brunet, M. (1996) The Fossil Floras of the Hamakoussou Basin, Lower Cretaceous of Northern Cameroon: Biostratigraphic Correlations with the Benue Trench, Paleogeographical Implications. Bulletin des Centres de Recherches Exploration-Production Elf-Aquitaine, 16, 145-173.
[13]
Dawaï, D. (2014) The Guider and Bossoum-Pologozom plutons (Pan-African Range in Northern Cameroon): Petrographic, Structural, Magnetic and Geochronological Analysis and Geodynamic Implication. Doctoral Thesis, University of Toulouse.
[14]
Schwoerer, P. (1965) Geological Reconnaissance Map at the Scale of 1:500,000 and Explanatory Notice on the Garoua-Est Sheet.
[15]
Ndjeng, E. (1992) Geodynamic Evolution Model of Two Lower Cretaceous Basins of North Cameroon: Babouri-Figuil and Mayo Oulo-Léré. University of Yaoundé.
[16]
Frey, F.A., Green, D.H. And Roy, S.D. (1978) Integrated Models of Basalt Petrogenesis: A Study of Quartz Tholeiites to Olivine Melilitites from South Eastern Australia Utilizing Geochemical and Experimental Petrological Data. Journal of Petrology, 19, 463-513. https://doi.org/10.1093/petrology/19.3.463
[17]
Bas, M.J.L., Maitre, R.W.L., Streckeisen, A. And Zanettin, B. (1986) A Chemical Classification of Volcanic Rocks Based on the Total Alkali-Silica Diagram. Journal of Petrology, 27, 745-750. https://doi.org/10.1093/petrology/27.3.745
[18]
Le Maître, R.W. (2002) Igneous Rocks. A Classification and Glossary of Terms. Recommendations of the International Union of Geological Sciences Sub Commission on the Systematics of Igneous Rocks. Cambridge University Press.
[19]
Miyashiro, A. (1974) Volcanic Rock Series in Island Arcs and Active Continental Margins. American Journal of Science, 274, 321-355. https://doi.org/10.2475/ajs.274.4.321
[20]
Winchester, J.A. and Floyd, P.A. (1976) Geochemical Magma Type Discrimination: Application to Altered and Metamorphosed Basic Igneous Rocks. Earth and Planetary Science Letters, 28, 459-469. https://doi.org/10.1016/0012-821x(76)90207-7
[21]
Pearce, J.A. (1996) A User’s Guide to Basalt Discrimination Diagrams. Trace Element Geochemistry of Volcanic Rocks: Application for Massive Sulphide Exploration. Geological Association of Canada, Short Course Notes, 12, 79-113.
[22]
Floyd, P.A. and Winchester, J.A. (1975) Magma Type and Tectonic Setting Discrimination Using Immobile Elements. Earth and Planetary Science Letters, 27, 211-218. https://doi.org/10.1016/0012-821x(75)90031-x
[23]
Pearce, J.A. (1975) Basalt Geochemistry Used to Investigate Past Tectonic Environments on Cyprus. Tectonophysics, 25, 41-67. https://doi.org/10.1016/0040-1951(75)90010-4
[24]
Ould-Yahoui, A., Sbai, O., Baranger, K., Bernard, A., Gueye, Y., Charrat, E., et al. (2013) Role of Matrix Metalloproteinases in Migration and Neurotrophic Properties of Nasal Olfactory Stem and Ensheathing Cells. Cell Transplantation, 22, 993-1010. https://doi.org/10.3727/096368912x657468
[25]
McDonough, W.F. and Sun, S.-S. (1995) The Composition of the Earth. Chemical Geology, 120, 223-253. https://doi.org/10.1016/0009-2541(94)00140-4
[26]
Sun, S.-. and McDonough, W.F. (1989) Chemical and Isotopic Systematics of Oceanic Basalts: Implications for Mantle Composition and Processes. Geological Society, London, Special Publications, 42, 313-345. https://doi.org/10.1144/gsl.sp.1989.042.01.19
[27]
Ngounouno, I., Déruelle, B., Guiraud, R. and Vicat, J. (2001) Magmatismes tholéiitique et alcalin des demi-grabens crétacés de Mayo Oulo-Léré et de Babouri–Figuil (Nord du Cameroun-Sud du Tchad) en domaine d’extension continentale. Comptes Rendus de l’Académie des Sciences—Series IIA—Earth and Planetary Science, 333, 201-207. https://doi.org/10.1016/s1251-8050(01)01626-3
[28]
Vicat, J., Ngounouno, I. and Pouclet, A. (2001) Existence de dykes doléritiques anciens à composition de tholéiites continentales au sein de la province alcaline de la ligne du Cameroun. Implication sur le contexte géodynamique. Comptes Rendus de l’Académie des Sciences—Series IIA—Earth and Planetary Science, 332, 243-249. https://doi.org/10.1016/s1251-8050(01)01526-9
[29]
Tchouankoue, J.P., Simeni Wambo, N.A., Kagou Dongmo, A. and Li, X. (2014) 40Ar/39Ar Dating of Basaltic Dykes Swarm in Western Cameroon: Evidence of Late Paleozoic and Mesozoic Magmatism in the Corridor of the Cameroon Line. Journal of African Earth Sciences, 93, 14-22. https://doi.org/10.1016/j.jafrearsci.2014.01.006
[30]
Pierre Tchouankoue, J. (2012) Petrology, Geochemistry, and Geodynamic Implications of Basaltic Dyke Swarms from the Southern Continental Part of the Cameroon Volcanic Line, Central Africa. The Open Geology Journal, 6, 72-84. https://doi.org/10.2174/1874262901206010072
[31]
Nkouandou, O.F., Bardintzeff, J., Mahamat, O., Fagny Mefire, A. and Ganwa, A.A. (2017) The Dolerite Dyke Swarm of Mongo, Guéra Massif (Chad, Central Africa): Geological Setting, Petrography and Geochemistry. Open Geosciences, 9, 138-150. https://doi.org/10.1515/geo-2017-0012
[32]
Nkouandou, O.F., Ngounouno, I., Déruelle, B., Ohnenstetter, D., Montigny, R. and Demaiffe, D. (2007) Petrology of the Mio-Pliocene Volcanism to the North and East of Ngaoundéré (Adamawa, Cameroon). Comptes Rendus. Géoscience, 340, 28-37. https://doi.org/10.1016/j.crte.2007.10.012
[33]
Nkouandou, O., Bardintzeff, J., Dogsaye, P. and Mefire, A. (2016) Geochemistry and Petrogenesis of Mafic Doleritic Dykes at Mbaoussi (Adamawa Plateau, Cameroon, Central Africa). Journal of Geography, Environment and Earth Science International, 8, 1-18. https://doi.org/10.9734/jgeesi/2016/28198
[34]
Chamboredon, R. (2015) Characterization and Origin of Alkaline Magmas and Fluids under the Jbel Saghro Volcanic Massif, Anti Atlas, Morocco. Doctoral Thesis, University of Montpellier.
[35]
Shaw, D.M. (1970) Trace Element Fractionation during Anatexis. Geochimica et Cosmochimica Acta, 34, 237-243. https://doi.org/10.1016/0016-7037(70)90009-8
[36]
Klamadji, M.N., Dedzo, M.G., Tchameni, R. and Dawaï, D. (2020) Petrography and Geochemical Characterization of Dolerites from Figuil (Northern Cameroon) and Léré (Southwestern Chad). International Journal of Geosciences, 11, 459-482. https://doi.org/10.4236/ijg.2020.117023
[37]
Klamadji, M.N. (2021) Petrology and Geochemistry of the Mafic Hypovolcanic Formations of Figuil (North Cameroon) and Lrée (Southwest Chad): Geodynamic Implication. University of Maroua.
[38]
Klamadji, M.N., Dedzo, M.G., Tchameni, R., Hamadjoda, D.D., Nyotok, P.C.B.A. and Onana, G. (2021) Fractional Crystallization and Crustal Contamination of Doleritic and Trachytic Dykes Crosscutting the Cretaceous Sedimentary Basins from Figuil (North Cameroon) and Léré (South-Western Chad): Geodynamic Implications. Journal of Geoscience and Environment Protection, 9, 190-210. https://doi.org/10.4236/gep.2021.912012
[39]
Halliday, A.N., Davidson, J.P., Hildreth, W. and Holden, P. (1991) Modelling the Petrogenesis of High Rb/Sr Silicic Magmas. Chemical Geology, 92, 107-114. https://doi.org/10.1016/0009-2541(91)90051-r
[40]
Taylor, S.R. and McLennan, S.M. (1985) The Continental Crust: It’s Composition and Evolution. Blackwell Publications.
[41]
Doumnang, J.C. (2006) The Geology of the Neoproterozoic Formations of Mayo-Kebbi (S-W Chad). Doctoral Thesis, University of Orléans.
[42]
Isseini, M., André-Mayer, A., Vanderhaeghe, O., Barbey, P. and Deloule, E. (2012) A-type Granites from the Pan-African Orogenic Belt in South-Western Chad Constrained Using Geochemistry, Sr-Nd Isotopes and U-Pb Geochronology. Lithos, 153, 39-52. https://doi.org/10.1016/j.lithos.2012.07.014
[43]
Wager, L.R. and Deer, W.A. (1939) Olivines from the Skaergaard Intrusion, Kangerdlugssuak, East Greenland. American Mineralogist, 24, 18-25.
[44]
Cabanis, B. and Thieblemont, D. (1988) La discrimination des tholeiites continentales et des basaltes arriere-arc; Proposition d’un nouveau diagramme, le triangle Th-3xTb-2xTa. Bulletin de la Société Géologique de France, 6, 927-935. https://doi.org/10.2113/gssgfbull.iv.6.927
[45]
Arth, J.G. (1976) Behavior of Trace Elements during Magmatic Processes-Summary of Theoretical Models and Their Applications. Journal of Research of the U.S. Geological Survey, 4, 41-47.
[46]
DePaolo, D.J. (1981) Trace Element and Isotopic Effects of Combined Wall Rock Assimilation and Fractional Crystallisation, Earth Planet. Science Letters, 84, 59-68.
[47]
Marsh, J.S. (1989) Geochemical Constraints on Coupled Assimilation and Fractional Crystallization Involving Upper Crustal Compositions and Continental Tholeiitic Magma. Earth and Planetary Science Letters, 92, 70-80. https://doi.org/10.1016/0012-821x(89)90021-6
[48]
Valbracht, P.J., Helmers, H. and Beunk, F.F. (1991) Early Proterozoic Continental Tholeiites from Western Bergslagen, Central Sweden, I. Petrology, Geochemical Petrogenesis and Geotectonic Setting. Precambrian Research, 52, 187-214. https://doi.org/10.1016/0301-9268(91)90080-t
[49]
Cadman, A.C., Tarney, J., Bridgwater, D., Mengel, F., Whitehouse, M.J. and Windley, B.F. (2001) The Petrogenesis of the Kangâmiut Dyke Swarm, W. Greenland. Precambrian Research, 105, 183-203. https://doi.org/10.1016/s0301-9268(00)00111-x
[50]
Srivastava, R.K. and Singh, R.K. (2004) Trace Element Geochemistry and Genesis of Precambrian Sub-Alkaline Mafic Dikes from the Central Indian Craton: Evidence for Mantle Metasomatism. Journal of Asian Earth Sciences, 23, 373-389. https://doi.org/10.1016/s1367-9120(03)00150-0
[51]
Cox, K.G. and Hawkesworth, C.J. (1985) Relative Contribution of Crust and Mantle to Flood Basalt Magmatism, Mahabaleshwar, Deccan Traps. Philosophic Transaction Royal Society London A, 310, 627-641.
[52]
Leeman, W.P. and Hawkesworth, C.J. (1986) Open Magma Systems: Trace Element and Isotopic Constraints. Journal of Geophysical Research: Solid Earth, 91, 5901-5912. https://doi.org/10.1029/jb091ib06p05901
[53]
Pearce, J.A. (1982) Trace Elements Characteristics of Lavas from Destructive Plate Boundaries. Wiley.
[54]
Nlomngan, J.P.S., Penaye, J., Tchameni, R., Owona, S., Ibohn, A.P.M., Nsifa, E.N., etal. (2019) Geochemical Characterization of Boula Ibi Granitoids and Implications in Geodynamic Evolution. Journal of Geography and Geology, 11, 13. https://doi.org/10.5539/jgg.v11n4p13
[55]
Condie, K.C. (1997) Sources of Proterozoic Mafic Dyke Swarms: Constraints from Thta and Layb Ratios. Precambrian Research, 81, 3-14. https://doi.org/10.1016/s0301-9268(96)00020-4
[56]
Touil, A., Bilal, E. and Boukhar, A.E. (2015) Distinction of Two Tholeiitic Families among the Late-Pan-African Dolerites of Siroua (Central Anti-Atlas, Morocco).
[57]
Hofmann, A.W. (1988) Chemical Differentiation of the Earth: The Relationship between Mantle, Continental Crust, and Oceanic Crust. Earth and Planetary Science Letters, 90, 297-314. https://doi.org/10.1016/0012-821x(88)90132-x
[58]
Hollanda, M.H.B.M., Pimentel, M.M., Oliveira, D.C. and de Sá, E.F.J. (2006) Lithosphere-Asthenosphere Interaction and the Origin of Cretaceous Tholeiitic Magmatism in Northeastern Brazil: Sr-Nd-Pb Isotopic Evidence. Lithos, 86, 34-49. https://doi.org/10.1016/j.lithos.2005.04.004
[59]
Dostal, J., Baragar, W.R.A. and Dupuy, C. (1983) Geochemistry and Petrogenesis of Basaltic Rocks from Coppermine River Area, Northwest Territories. Canadian Journal of Earth Sciences, 20, 684-698. https://doi.org/10.1139/e83-062
[60]
Dupuy, C. and Dostal, J. (1984) Trace Element Geochemistry of Some Continental Tholeiites. Earth and Planetary Science Letters, 67, 61-69. https://doi.org/10.1016/0012-821x(84)90038-4
[61]
Marzoli, A., Bertrand, H., Knight, K.B., Cirilli, S., Buratti, N., Vérati, C., et al. (2004) Synchrony of the Central Atlantic Magmatic Province and the Triassic-Jurassic Boundary Climatic and Biotic Crisis. Geology, 32, 973-976. https://doi.org/10.1130/g20652.1
[62]
Chabou, M.C., Bertrand, H. and Sebaï, A. (2010) Geochemistry of the Central Atlantic Magmatic Province (CAMP) in South-Western Algeria. Journal of African Earth Sciences, 58, 211-219. https://doi.org/10.1016/j.jafrearsci.2010.02.009
[63]
Nkouandou, O.F., Ngounouno, I., Déruelle, B., Ohnenstetter, D., Montigny, R. and Demaiffe, D. (2007) Petrology of the Mio-Pliocene Volcanism to the North and East of Ngaoundéré (Adamawa, Cameroon). Comptes Rendus. Géoscience, 340, 28-37. https://doi.org/10.1016/j.crte.2007.10.012
[64]
Bertrand, H., Dostal, J. and Dupuy, C. (1982) Geochemistry of Early Mesozoic Tholeiites from Morocco. Earth and Planetary Science Letters, 58, 225-239. https://doi.org/10.1016/0012-821x(82)90196-0
[65]
Alibert, C. (1985) A Sr-Nd Isotope and REE Study of Late Triassic Dolerites from the Pyrenees (France) and the Messejana Dyke (Spain and Portugal). Earth and Planetary Science Letters, 73, 81-90. https://doi.org/10.1016/0012-821x(85)90036-6
[66]
Morata, D., Puga, E., Demant, A. and Aguirre, L. (1997) Geochemistry and Tectonic Setting of the «Ophites» from the External Zones Ofthe Betic Cordilleras (S. Spain). Estudios Geológicos, 53, 107-120. https://doi.org/10.3989/egeol.97533-4236
[67]
Nono, G.D.K., Wotchoko, P., Ganno, S., Njinchuki, D.N. and Nzenti, J.P. (2013) Petrochemical Characterization of Two Distinct Types of Dolerites from Bafoussam Area, West Cameroon. International Journal of Geosciences, 4, 1131-1144. https://doi.org/10.4236/ijg.2013.48107
[68]
Meschede, M. (1986) A Method of Discriminating between Different Types of Mid-Ocean Ridge Basalts and Continental Tholeiites with the Nb 1bZr 1bY Diagram. Chemical Geology, 56, 207-218. https://doi.org/10.1016/0009-2541(86)90004-5
[69]
Leterrier, J., Maury, R.C., Thonon, P., Girard, D. and Marchal, M. (1982) Clinopyroxene Composition as a Method of Identification of the Magmatic Affinities of Paleo-Volcanic Series. Earth and Planetary Science Letters, 59, 139-154. https://doi.org/10.1016/0012-821x(82)90122-4
[70]
Pearce, J.A. and Norry, M.J. (1979) Petrogenetic Implications of Ti, Zr, Y, and Nb Variations in Volcanic Rocks. Contributions to Mineralogy and Petrology, 69, 33-47. https://doi.org/10.1007/bf00375192
[71]
Kelemen, P.B., Shimizu, N. and Dunn, T. (1993) Relative Depletion of Niobium in Some Arc Magmas and the Continental Crust: Partitioning of K, Nb, La and Ce during Melt/Rock Reaction in the Upper Mantle. Earth and Planetary Science Letters, 120, 111-134. https://doi.org/10.1016/0012-821x(93)90234-z
[72]
Guiraud, R. and Maurin, J.C. (1991) Le Rifting en Afrique au Cretace inferieur; Synthese structurale, Mise en evidence de deux etapes dans la genese des bassins, Relations avec les ouvertures oceaniques peri-africaines. Bulletin de la Société Géologique de France, 162, 811-823. https://doi.org/10.2113/gssgfbull.162.5.811
[73]
Mullen (1983) MnO-TiO2-P2O5 Diagram for Basaltic Samples from Khangai-Khentei Belt. The Samples Are Most Similar to Oceanic Island Alkaline Basalt. https://warmada.staff.ugm.ac.id/Graphics/gnuplot/petclass/mullen.html
