TITLE:
Petrochemical Characterization of Two Distinct Types of Dolerites from Bafoussam Area, West Cameroon
AUTHORS:
Gus Djibril Kouankap Nono, Pierre Wotchoko, Sylvestre Ganno, Divine Ngong Njinchuki, Jean Paul Nzenti
KEYWORDS:
Doleritic Dyke; Petrochemical; Alkaline; Tholeiitic; Intraplaque; Bafoussam
JOURNAL NAME:
International Journal of Geosciences,
Vol.4 No.8,
October
18,
2013
ABSTRACT: Two petrochemical types of doleritic dykes have been distinguished in Bafoussam area: 1) the olivine-bearing dolerites which are the most representative are dark green, showing characteristics of alkaline basalts and, 2) the calcite-bearing dolerites are grayish green, showing characteristics of tholeiitic basalts. The studied dolerites are less differentiated (1 FeOt/MgO 2); they present the evolution of a subalkaline magma following a calc-alkaline series (alkaline dolerites) and the tholeiitic series (tholeitiic dolerite). The chondrite normalized multielement spider diagrams of all the dolerites show a pronounced depletion in Ba, Th, and enrichment in Rb. Their geotectonic context is inferred to be intraplate and the contrast between the two types is probably due to a diverse source: crustal source for calcite-bearing dolerites and mantle source for olivine-bearing dolerites.