Petrochemical Characterization of Two Distinct Types of Dolerites from Bafoussam Area, West Cameroon  

作　　者：Gus Djibril Kouankap Nono Pierre Wotchoko Sylvestre Ganno Divine Ngong Njinchuki Jean Paul Nzenti 

机构地区：[1]1Department of Geology, HTTC, University of Bamenda, Bamenda, Cameroon 2Laboratory of Petrology and Structural Geology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon [2]Department of Geology, HTTC, University of Bamenda, Bamenda, Cameroon [3]Economic Geology Unit, Department of Geology, University of Buea, Buea, Cameroon [4]Laboratory of Petrology and Structural Geology, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon

出　　处：《International Journal of Geosciences》2013年第8期1131-1144,共14页地球科学国际期刊（英文）

摘　　要：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.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.

关 键 词：Doleritic DYKE PETROCHEMICAL Alkaline THOLEIITIC Intraplaque Bafoussam 

分 类 号：P5[天文地球—地质学]