The Quaternary Cameroon Volcano

Cameroon Volcano (CV) is a large elliptical (50×35 km wide) stratovolcano elongated in the SW-NE direction, built on a Pan-African granito-gneissic basement covered by Cretaceous to Quaternary strata (Suh et al., 2003; Tsafack et al., 2009). It culminates at 4095 m with a volume of ~1,200 km3 and includes several geological features: (1) ashes, cinders and, scoriaceous lapilli, blocks and bombs whose accumulation constructed nearly 140 cones. These cones, mainly broken, have high slopes (25-43°); (2) aa-type mafic lava emitted at the base of cones with variable widths of 30 to ~120 m, the length from 3 km (SW flanks) to ~9 km (NE flanks) and a distal front of 15 m high (Déruelle et al., 2000; Suh et al., 2003). These lavas belong to a typical alkaline series, weakly differentiated (basanite, alkaline basalt, hawaiite, and mugearite), characteristic of the interior of plates. Basanite and basalt in places possess xenoliths (1-5 x 0.5-4 cm) of dunite, wehrlite and clinopyroxenite (Tsafack, 2009); (3) Mount Etindé that is located on the southwestern flanks of CV. It culminates at 1713 m and is exceptionally composed entirely of silica-undersaturated rocks called nephelinite (Mama et al., 2021); (4) two maars (Debundscha and Bomana) respectively located at the SW and the NW slopes (Tsafack, 2009); (5) several tectonic fractures due to the alignment of cones and several vents and, rifts.