The Ziver volcanism, located in northern Cameroon within the Central African Rift, forms an integral part of the Cameroon–Chad Volcanic Line (CCVL). The new mineralogical, geochemical, and isotopic data presented here provide fresh insights into the sources and petrogenesis of lavas from this little-studied area. The primary mineral assemblage consists of olivine, clinopyroxene, Fe–Ti oxides, and feldspars. Clinopyroxenes are predominantly calcic, with compositions ranging from diopside to clinoenstatite. Feldspars occur as andesine in mafic rocks, whereas in felsic lavas they are represented by K-albite and Na-sanidine. The volcanic suite defines a bimodal alkaline series composed of mafic (basanite, basalt, hawaiite) and felsic (trachyte, rhyolite) lavas, characterized by moderate to high alkali contents (K 2 O + Na 2 O = 4.10–12.25 wt%). These lavas display moderately enriched radiogenic isotope signatures, with 87 Sr/ 86 Sr ratios of 0.70311–0.71856 and 143 Nd/ 144 Nd ratios of 0.51276–0.51295. Geochemical and isotopic data (0.7036 ε Ndi < 6.44) indicate an intraplate OIB affinity, derived from low-degree (1–3%) partial melting of an enriched garnet lherzolite mantle plume source. Magmatic differentiation is dominated by fractional crystallization with minimal crustal contamination, consistent with the CCVL as a whole.
Dili-Rake et al. (Tue,) studied this question.