PETROGRAPHY AND GEOCHEMICAL CHARACTERIZATION OF THE LAME ALKALINE BASALTS (SOUTHWESTERN MAYO KEBBI) IN THE CAMEROON-CHAD VOLCANIC LINE: IMPLICATIONS FOR TECTONIC EVOLUTION AND MANTLE SOURCE
- Department of Mining, New and Renewable Energies, National Higher Institute of the Sahara and Sahel, Iriba, Chad.
- Department of Geology, Faculty of exact and applied Sciences of Farcha, University of N Djamena,, B.P. 1027, N Djamena, Tchad.
- Department of Mining and Geological Engineering, Faculty of Life and Earth Sciences, Pala University, Pala, Chad.
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The Lame basalts, located in the Mayo Kebbi massif in southwestern Chad, display petrographic and geochemical features typical of intraplate alkaline magmas. Their homogeneous mineralogical composition (clinopyroxene, olivine, plagioclase, and iron oxides), combined with a relative enrichment in LREE compared to HREE, as well as V, Cr, Mg# contents and Nb/U ratios characteristic of OIB, indicate a HIMU-type mantle source with residual garnet. Variations in major and trace elements show that magmatic differentiation was dominated by fractional crystallization, with no evidence of crustal contamination. These geochemical signatures closely resemble those of alkaline magma observed in the Tibesti, OuaddaI and Lake Chad volcanic provinces, confirming their affiliation with the northern extension of the Cameroon Volcanic Line.
Felix Nenadji Djerossem, Jean Wanloana Djobelao and Gustave Ronangbaissemia (2026); PETROGRAPHY AND GEOCHEMICAL CHARACTERIZATION OF THE LAME ALKALINE BASALTS (SOUTHWESTERN MAYO KEBBI) IN THE CAMEROON-CHAD VOLCANIC LINE: IMPLICATIONS FOR TECTONIC EVOLUTION AND MANTLE SOURCE, Int. J. of Adv. Res. (Feb), ISSN 2320-5407. DOI URL: https://dx.doi.org/
