Petrogenesis of Magnesian High-K Granitoids From Bitkine (Centrechad Massif): Major and Trace Elements Constraints

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  •   Mbaihoudou Diontar

  •   Jean Claude Doumnang

  •   Maurice Kwékam

  •   Zagalo Al-hadj Hamid

  •   Armand Kagou Dongmo

  •   Julios Efon Awoum

  •   Jules Tcheumenak Kouémo

Abstract

Major and trace element data were used to constrain the nature and origin of the Bitkine gabbro-diorite magma.The gabbro-diorites of Bitkine within the Guéra Massif, and associated microgranular enclaves consist of plagioclase, k-feldspar, clinopyroxene, amphibole, biotite and quartz. Gabbro-diorites and enclaves are basic to intermediate rocks. They are high-K magnesian calc-alkaline with shoshonite affinity. ΣREE range from 132 to 436 ppm in gabbro-diorites, while they are from 134 to 207 ppm in enclaves. LREE are weakly enriched compared to HREE (La/Yb)N = (12.23 -41.40) and (6.20-31.86) respectively in gabbro-diorites and enclaves. These rocks show a weak negative anomaly in europium (Eu/Eu* = 0.78-1.07). They are rich in Ba and Sr, and show negative anomalies in Nb, Ta and Ti. The Nb/Ta, Rb/Cs and Ba/Nb ratios of the Bitkine gabbro-diorites and their enclaves indicate that they are derived from mantle magma modified by subducted fluids. This magma during its evolution by fractional crystallization was contaminated by crustal materials.


Keywords: Bitkine, Gabbro-diorite, High-k magnesian, Enriched mantle, Fractional crystallization

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How to Cite
Diontar, M., Doumnang, J. C., Kwékam, M., Al-hadj Hamid, Z., Kagou Dongmo, A., Efon Awoum, J., & Tcheumenak Kouémo, J. (2020). Petrogenesis of Magnesian High-K Granitoids From Bitkine (Centrechad Massif): Major and Trace Elements Constraints. European Journal of Environment and Earth Sciences, 1(5). https://doi.org/10.24018/ejgeo.2020.1.5.78

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