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Journal of Geosciences and Geomatics. 2019, 7(5), 221-236
DOI: 10.12691/JGG-7-5-2
Original Research

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
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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

Copyright

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