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Re ´sumeĹes laves basaltiques de la plaine de Kumba contiennent des xe ´nolithes de pe ´ridotites mantelliques a `spinelle. Leur mine ´ralogie ainsi que les compositions en e ´le ´ments majeurs et traces des roches totales et des clinopyroxe `nes indiquent un manteau supe ´rieur essentiellement lherzolitique, soit fertile, soit tre `s peu fondu, et qui n'a e ´te ´que peu ou pas affecte ´par un me ´tasomatisme cryptique. Ce manteau, tre `s homoge `ne, est tre `s diffe ´rent de celui qui apparaı ˆt dans d'autres gisements d'enclaves de pe ´ridotites de la ligne du Cameroun, et notamment dans celui a `l'aplomb de la plaine volcanique de Nyos.

Mount Cameroon is a Plio-Quaternary volcanic massif, without a central crater, made up ofmore than 140 pyroclastic cones. It is one of the active volcanoes of the Cameroon Line. Mount Cameroon magmatic inclusions are found in microdroplets trapped in the early minerals (olivines) from the pyroclastic products. The analysis of these magmatic inclusions allowed us to find primitive liquids compared to lavas. Major elements study of the magmatic inclusions, trapped in the most magnesian olivines (Mg#84-86) of Mount Cameroon revealed "primitive" liquids of basanite and alkaline basalt type with variable composition compared to the much more uniform basalts of the magmatic series of Mount Cameroon. The study of these trapped liquids shows that:  (i)- the original primitive lavas did not undergo the process of evolution by FC, but rather underwent fundamentally (or exclusively) the process of partial melting; (ii) the emitted lavas, evolved essentially by FC; (iii) the variations in the trace element contents of the primitive liquids directly reflect a variation in the rate of partial melting of a homogeneous mantelic source. The very high La/Yb ratios of the Mount Cameroon inclusions (> 20) characterize a garnet lherzolite source. Spectra of the magmatic inclusions show a negative anomaly or depletion in K, Rb and Ba as those of HIMU. The "primitive" liquids and lavas of Mount Cameroon represent a co-genetic sequence formed by varying degrees of partial melting of a source considered as homogeneous.