Open AccessGeochemistry of Volcanic Rocks of Beka, North East of Ngaoundéré (Adamawa Plateau, Cameroon): Petrogenesis and Geodynamic Context
Author(s) -
Pauline Wokwenmendam Nguet,
Benjamin Ntiéche,
Joseph Legrand Tchop,
Bouba Christian Mana,
Eddy Ferdinand Mbossi
Publication year - 2021
Publication title -
journal of geological research
Language(s) - English
Resource type - Journals
ISSN - 2630-4961
DOI - 10.30564/jgr.v3i3.3325
Subject(s) - felsic , geology , geochemistry , basalt , trachyte , petrogenesis , olivine , porphyritic , plagioclase , nepheline , fractional crystallization (geology) , volcanic rock , petrology , mafic , volcano , quartz , paleontology
Beka area is situated in the Adamaoua Plateau of Cameroon in central Arica. Lavas in this area has not been studied before the present work.The volcanism of Beka is characterized by basalt, trachyte and phonolite domes and flows. The petrographic study shows that basaltic lavas have porphyritic microlitic textures. The felsic lavas indicate trachytic textures.The rocks are composed of olivine, clinopyroxene, plagioclase and irontitanium oxide minerals for the basalts; clinopyroxene, alkali feldspar (including foids), sphene and titanomagnetite for the felsic lavas. Chemical analyses show that basaltic lavas are basanites. Felsic lavas contain modal feldspathoid (nepheline in phonolites). All these lavas belong to the same series, because the felsic lavas are derived from the differentiation of basaltic lavas by fractional crystallization. They show an alkaline nature according to their geochemistry. Trace elements including Rare Earth Elements characteristics show that rocks emplaced in the Winthin Plate volcanic zone. They derived from an evolved parent magma showing a low degree of partial melting and characteristics closer to a modified and evolved primitive spinel lherzolite.