Lithospheric mantle refertilization by DMM-derived melts beneath the Cameroon Volcanic Line—a case study of the Befang xenolith suite (Oku Volcanic Group, Cameroon)

Abstract The origin and evolution of subcontinental lithospheric mantle (SCLM) are important issues Earth’s chemical physical evolution. Here, we report detailed textural analyses on a xenolith suite from Befang (Oku Volcanic Group, Cameroon Line), which represents major tectono-magmatic structure the African plate. samples sourced spinel-facies dominated by lherzolites. Their texture is cataclastic to porphyroclastic, foliation defined grain-size variation alignment spinel occurs in part peridotites. Spinel interstitial has amoeboidal shape. Clinopyroxene REE patterns similar those Depleted MORB Mantle (DMM) except LREEs, vary depleted enriched. A-type olivine fabric subset one harzburgite 7 lherzolites studied EBSD. Orthopyroxene shows deformation consistent with olivine. LREE-enriched clinopyroxene equivalent orthopyroxene olivine, whereas LREE-depleted oriented independently host rock fabric. textural, thermobarometric constraints indicate that section was refertilised MORB-like melt at pressures 1.0–1.4 GPa temperatures slightly above 1200–1275 °C. olivine-orthopyroxene framework preserve protolith In contrast, clinopyroxene, showing discordant relative framework, crystallized infiltrating melt. element REEs composition minerals forming peridotites subsequent reequilibration 930–1000 This followed formation websterite veins mantle, can be linked Cenozoic volcanism Line also brought xenoliths surface. study therefore supports fertile SCLM via refertilization rather than extraction small fractions, further emphasizes involvement melts this process.