Djerossem, F., Zeh, A., Isseini, M., Vanderhaeghe, O., Berger, J. and Ganne, J. (2021) U-Pb-Hf Isotopic Systematics of Zircons from Granites and Metasediments of Southern Ouaddaï (Chad), Implications for Crustal Evolution and Provenance in the Central Africa Orogenic Belt. Precambrian Research, 361, Article ID: 106233.
https://doi.org/10.1016/j.precamres.2021.106233

has been cited by the following article:

• TITLE: Petrogenesis and Tectonic Significance of Meta-Mafic Rocks from Eastern Mayo Kebbi Massif (Pala), Chad: Evidence for a Depleted Mantle Source and Intra-Oceanic Subduction

  AUTHORS: Félix Nenadji Djerossem, Gustave Ronang Baïssemia, Moussa Ngarena Klamadji, Mbaguedje Diondoh

  KEYWORDS: Meta-Mafic Rocks, Mayo Kebbi, N-MORB, Depleted Mantle, Central African Orogenic Belt

  JOURNAL NAME: International Journal of Geosciences, Vol.16 No.10, October 29, 2025

  ABSTRACT: Meta-mafic rocks from the eastern Mayo Kebbi massif (Pala area, Chad) provide new insights into the geodynamic evolution of the Central African Orogenic Belt (CAOB). Petrographic and geochemical analyses reveal that the meta-mafic rocks consist of amphibolites and métagabbros, derived from a basalts protolith. These rocks exhibit calc-alkaline to tholeiitic affinities and are characterized by granoblastic and microlitic porphyritic textures. Enrichment in light rare earth elements (LREE), parallel REE patterns, and systematic variations in major and trace elements indicate that fractional crystallization was the dominant differentiation process. These rocks formed in a primitive arc magmatic setting, with source components including N-MORB-type and depleted mantle. Discrimination diagrams (e.g., V/Ti vs. Zr, Th/Yb vs. Nb/Yb) indicate an intra-oceanic subduction influence, supported by negative anomalies in Nb-Ta, Zr-Hf and Ti. These findings support a tectonic model involving an active margin between a mid-ocean ridge and an intra-oceanic arc, reflecting the closure or subduction of an ancient oceanic domain.