Contents lists available at ScienceDirect Journal of African Earth Sciences journal homepage: www.elsevier.com/locate/jafrearsci Petrology and geochemistry of lavas from Gawar, Minawao and Zamay volcanoes of the northern segment of the Cameroon volcanic line (Central Africa): Constraints on mantle source and geochemical evolution Merlin Gountié Dedzo a,* , Asobo Nkengmatia Elvis Asaah b,c,d , Eric Martial Fozing e , Boris Chako Tchamabé f , Ghislain Tefogoum Zangmo g , Nguihdama Dagwai a , Dieudonné Tchokona Seuwui h , Pierre Kamgang i , Festus Tongwa Aka j , Takeshi Ohba k a Department of Life and Earth Sciences, High Teachers' Training College, University of Maroua, P.O. Box. 55, Maroua, Cameroon b Department of Mines, Ministry of Mines, Industry and Technological Development, P.O. Box 70, Yaoundé, Cameroon c Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-Ku, Tokyo, 152-8551, Japan d Department of Geology, Mining and Environmental Sciences, University of Bamenda, Cameroon e Laboratory of Environmental Geology, University of Dschang, P.O. Box 67, Dschang, Cameroon f CONACYT-Centro de Ingeniería y Desarrollo Industrial, Av. Playa Pie de la Cuesta 702, Desarrollo San Pablo, 76125, Querétaro, Qro, Mexico g Department of Earth Sciences, Faculty of Sciences, University of Maroua, P.O. Box 814, Maroua, Cameroon h Laboratoire de Géologie, École Normale Supérieure, Université de Yaoundé I, BP 47, Yaoundé, Cameroon i Department of Earth Sciences, University of Yaoundé I, B.P. 812, Yaoundé, Cameroon j Institute for Geological and Mining Research (IRGM), Ministry of Scientific Research and Innovation (MINRESI), PO Box 4110, Yaounde, Cameroon k Department of Chemistry, School of Science, Tokai University, Hiratsuka, 259-1211, Japan ARTICLE INFO Keywords: Cameroon volcanic line Bimodal volcanism Fractional crystallization Sub-lithospheric mantle Sub-continental lithospheric mantle ABSTRACT The most important part of geochemical studies of lavas along the Cameroon Volcanic Line (CVL) has so far focused on the southern and central segments of the line leaving behind the northern-most part of the CVL with few and incomplete data. This study presents the case of the Gawar, Zamay and Minawao volcanoes, for which, for the first time, petrological and geochemical data comprising major and trace elements, and Strontium- Neodymium-Lead isotopes have been used to investigate the mantle source and the genetic relation between the felsic and mafic lavas in these areas. Volcanics in the Gawar are mainly basanites while those from Minawao and Zamay are essentially trachytes. The Nb/Ta and Zr/Hf ratios are similar for both the mafic and felsic rocks suggesting a dominant evolution of the magma by fractional crystallization. Primitive-mantle normalized multi- element diagrams of the mafic lavas are comparable to those reported in other volcanoes along the CVL; characterized by the depletion of Heavy Rare Earth Elements (HREE) and enrichment of Light Rare Elements (LREE), indicative of an enrichment and the presence of garnet in the source. Modeled results for melting using primitive mantle normalized values of Sm/Yb vs La/Sm indicate a low degree (< 2%) of partial melting of a source with less than 4% garnet. This is consistent with chondrite normalized REE patterns characterized by the fractionation of HREE relative LREE. Trace elements composition and isotope data preclude the significant role of the continental crust in the magmatism of the mafic rocks. However, during evolution to the felsic lavas, the role of the crust became more important. The ranges for 87 Sr/ 86 Sr (0.70356–0.70362), 143 Nd/ 144 Nd (0.512928–0.512931), 206 Pb/ 204 Pb (19.62–19.72), 207 Pb/ 204 Pb (15.65–15.68) and 208 Pb/ 204 Pb (39.31–39.45) isotopic composition for mafic samples (Gawar) are limited and fall within the range of mafic lavas studied along the CVL. The isotopic signatures and trace element characteristics are consistent with an asthenospheric origin, however with contribution from the sub-continental lithospheric Mantle (SCLM). The two sources have imparted characteristics of more than two mantle components involving the Depleted MORB-like mantle, HIMU and Enriched mantle (EM1). https://doi.org/10.1016/j.jafrearsci.2019.02.010 Received 27 May 2018; Received in revised form 16 December 2018; Accepted 5 February 2019 * Corresponding author. E-mail address: merlin.gountie@gmail.com (M. Gountié Dedzo). Journal of African Earth Sciences 153 (2019) 31–41 Available online 13 February 2019 1464-343X/ © 2019 Published by Elsevier Ltd. T