Petrology and geochemical framework of dolerites dykes of Temte, North Cameroon, Central Africa  

作　　者：M.Mey Atour J.M.Bardintzeff A.Fagny Mefire O.F.Nkouandou R.Tchameni A.Dinamou 

机构地区：[1]Department of Earth Sciences,Faculty of Sciences,University of Ngaoundere,P.O.Box 454,Ngaoundere,Cameroon [2]Sciences de la Terre,Volcanologie,Planetologie,UMR CNRS 8148 GEOPS,bat.504,Universite Paris-Saclay,91405 Orsay,France [3]Department of Mineral Engineering,Chemical Engineering and Mineral Industry School,University of Ngaounderanalyses,P.O.Box 454,Ngaoundere,Cameroon

出　　处：《Acta Geochimica》2021年第3期287-299,共13页地球化学学报（英文）

基　　金："Agence Universitaire de la Francophonie (AUF)" through the BAGL (Bureau Afrique Centrale et des Grands Lacs) for financial support of Le Projet de soutien aux équipes de recherche 2012/2013 (No 51110SU201) for supplement analyses;"Laboratoire GEOPS" of the University Paris-Saclay is thanked for financial support of thin sections and electron microprobe analyses。

摘　　要：The Temtebasement in North Cameroon is crosscut by dyke swarms with N 20°–40°trending,including dykes 15–30 m wide,up to 3 km-long.Representative rocks exhibit intersertal to sub-ophitic textures.Electron microprobe analyses identified diopside,augite,pargasite,biotite,Ti-magnetite,plagioclase,and sanidine.Whole-rock ICP-MS and ICP-AES chemical analyses showed compositions of basaltic andesite,basaltic trachyandesite and trachyandesite in composition.Igneous differentiation was likely governed by fractional crystallization associated with limited fluid metasomatism.Some lavas could have been moderately contaminated by crustal materials during feeding of local cracks through turbulent magma flows.Discrimination geochemical diagrams and immobile trace and REE element ratios show that the mantle source of Temtedolerites was a deep phlogopitebearing EMII mantle component and has undergone moderate to high partial melting rate.Correlations of fieldwork and analytical data with previous results evidence the Temtedolerite dyke swarms as fingerprints of crustal extension accompanying regional uplift in an active continental margin when early rifting led to the formation of the Poli marginal basin.

关 键 词：DOLERITE DYKE Temte Poli Cameroon Central Pan-African Fold Belt 

分 类 号：P588.12[天文地球—岩石学]