The Quaternary sediments of Lake Barombi Mbo, a crater lake in the volcanic chain of Cameroon, have been the object of numerous multidisciplinary studies (Giresse et al., 1991; Maley and Brenac, 1998). As such, this lake offers, together with Bosumtwi meteoritic impact lake (Talbot and Johannessen, 1992; Peck et al., 2004) in Ghana, one of the rare palaeoenvironmental histories of West Africa back to more than 25,000 yrs BP.