Ngwa, Caroline NehLenhardt, NilsLe Roux, PetrusMbassa, Benoit Joseph2020-01-292019-10Ngwa, C.N., Lenhardt, N., Le Roux, P. et al. 2019, 'The Mount Cameroon southwest flank eruptions : geochemical constraints on the subsurface magma plumbing system', Journal of Volcanology and Geothermal Research, vol. 384, pp. 179-188.0377-0273 (print)1872-6097 (online)10.1016/j.jvolgeores.2019.07.016http://hdl.handle.net/2263/73003With seven major eruptions in the 20th century, Mount Cameroon is one of the most active volcanoes in Africa. However, information on the volcano's plumbing system is still relatively scarce. In order to contribute to filling this knowledge gap, a geochemical, clinopyroxene geobarometry, and SrNd isotope study was carried out on samples collected from the 1922 and lower 1999 lava flows found on the SW flank of the volcano. Petrographic evidence shows a common crystallising mineral assemblage of olivine and clinopyroxene and/or plagioclase scattered in a microlite-rich groundmass. The total alkali-silica classification diagram shows that the lavas of 1922 exhibit basanitic compositions those of 1999 are predominantly basanites with some few hawaiites. The Sr isotope ratios for the 1999 samples in this study show values somewhat lower and higher than the limits obtained for historic Mount Cameroon samples so far. While major and trace element trends indicate fractional crystallisation processes, chemical and mineral disequilibrium textures are indicative of open-system processes such as magma mixing and magma chamber recharge. Variations in incompatible trace element ratios, which hardly change during fractional crystallisation, are also suggestive of open-system processes. Plots of K2O and Nb show a mixing trend between samples from these eruptions, implying a common magma chamber where remnant material from preceding eruptions was incorporated into succeeding eruptions. Clinopyroxene geobarometric calculations show this common dominant crystallisation depth at 23–29 km.en© 2019 Elsevier B.V. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Journal of Volcanology and Geothermal Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Journal of Volcanology and Geothermal Research, vol. 384, pp. 179-188, 2019. doi : 10.1016/j.jvolgeores.2019.07.016.Mount CameroonFlank eruptionsMagma chamber processesCrystallisation depthsPostprint Article