The camptonites from Mount Cameroon, Cameroon, Africa

Camptonites have been discovered at Mount Cameroon. They contain phenocrysts of olivine + clinopyroxene + plagioclase +/- kaersutite +/- bi and ocelli of nepheline or analcite and carbonates. Sr-87/Sr-86(i) values are similar to those of the basalts of Mount Cameroon (approximate to 0.7033). The camptonites are interpreted as resulting from fractional crystallization of a basaltic magma generated by a low degree of melting of an infra-lithospheric metasomatized mantle tapped by huge lithospheric cracks. (c) 2006 Academie des sciences. Publie par Elsevier SAS. Tous droits reserves.