Extreme source heterogeneity and complex contamination patterns along the Cameroon Volcanic Line: New geochemical data from the Bamoun plateau

Type Article
Date 2018-03
Language English
Author(s) Ziem A. Bidias Luc Achille1, 2, Chazot Gilles3, Moundi Amidou1, Nonnotte Philippe3
Affiliation(s) 1 : Univ Yaounde I, Fac Sci, Dept Sci Terre Univ, BP 812, Yaounde, Cameroon.
2 : Univ Yaounde I, Ecole Normale Super, Lab Geol, BP 047, Yaounde, Cameroon.
3 : Univ Brest UBO, Geosci Ocean, UMR 6538, IUEM, Pl Nicolas Copernic, F-29280 Plouzane, France.
Source Comptes Rendus Geoscience (1631-0713) (Elsevier France-editions Scientifiques Medicales Elsevier), 2018-03 , Vol. 350 , N. 3 , P. 100-109
DOI 10.1016/j.crte.2017.11.004
WOS© Times Cited 7
Keyword(s) Cameroon Volcanic Line, Geochemistry, Mantle source, Crustal contamination, Basalt
Abstract

We investigated mafic and felsic volcanic rocks from the Bamoun plateau, a magmatic province located north of Mount Cameroon, in the continental part of the Cameroon Volcanic Line (CVL). Basalts and dacites were probably emplaced more than 40 Ma ago, while basanites represent very young volcanic eruptions. Among the basalts, some of them have suffered crustal contamination during their uprise through the continental crust, and their primary trace element and isotopic compositions have been slightly modified. The formation of the dacites was also accompanied by some crustal contamination. Non-contaminated rocks show that the oldest magmas are transitional basalts formed by relatively high degrees of partial melting of a moderately enriched mantle source, probably containing pyroxenites. Recent basanites were produced by very low partial melting degrees of an enriched mantle source with HIMU composition, but different from the source of the nearby Mount Cameroon lavas. The mantle beneath the CVL is thus very heterogeneous, and the tendency towards more alkaline mafic-ultramafic compositions in the youngest volcanic manifestations along the CVL seems to be a general feature of all CVL.

Full Text
File Pages Size Access
Publisher's official version 10 1 MB Open access
195 KB Access on demand
104 KB Access on demand
175 KB Access on demand
150 KB Access on demand
309 KB Access on demand
Top of the page

How to cite 

Ziem A. Bidias Luc Achille, Chazot Gilles, Moundi Amidou, Nonnotte Philippe (2018). Extreme source heterogeneity and complex contamination patterns along the Cameroon Volcanic Line: New geochemical data from the Bamoun plateau. Comptes Rendus Geoscience, 350(3), 100-109. Publisher's official version : https://doi.org/10.1016/j.crte.2017.11.004 , Open Access version : https://archimer.ifremer.fr/doc/00638/74996/