 | | Journal (article/letter/editorial) | | volcanism in the Upper Benue valley, northern Cameroon (Central Africa) Received: 16 June 2002 / Accepted:...mean) occur in the Upper Benue valley, northern Cameroon (Central Africa). The complete alkaline series...mineralogy with aegirine-augite, richterite, and arfvedsonite phenocrysts. There is a large compositional...both the continental and oceanic sectors of the Cameroon Line. The Upper Benue valley basaltic magmas (87Sr/86Sr0...Garoua rift is the N120E–130E propagation in Cameroon of the Yola branch and is limited by strike-slip |  | | Journal (article/letter/editorial) | | Clinopyroxene from some felsic alkaline rocks of the Cameroon Line, central Africa: petrological implications...rocks belonging to the continental part of the Cameroon Line (CL). The investigated samples include both...kaersutite-bearing peralkaline phonolite of Nganha volcano, however, pyroxenes are rather poor in Na and...distinct pyroxene trends in trachytes from Nganha (Adamawa plateau) and Kapsiki (northernmost plateau)...contamination on the observed trends. Key-words: Cameroon Line, alkaline complexes, felsic rocks, Zr- and |  | | Journal (article/letter/editorial) | | addition to Sr-rich perrierite from the north Baikal region (Portnov, 1964), which are intermediate between...determination of samples from the Burpala massif, Baikal region (Mirkina et al., 1973), the Eastern Ghats of India...trachyte lava chevkinite (unconfirmed), Tarosero volcano, Tanzania (this paper, Table 1); perrierite, rhyodacite...composition of perrierite from the Roccamonfina volcano in Italy can be adequately represented by the balancing...variations in c/p from a trachyte lava of the Tarosero volcano, Tanzania, involve decreases in Al, LREE, Th and |  | | Report (issue) | | (Bottom) Carbonatite lava at Oldoinyo Lengai volcano, northern Tanzania. Courtesy Alexander J. Teague...and natrocarbonatite lavas at Oldoinyo Lengai volcano, Tanzania. . . . . . . . . . . . . . . . . . ....Hanley, Terry M. Seward, and Frederik Reutten 9. Cameroon Line alkaline magmatism (central Africa): A reappraisal...fingerprints of mantle metasomatism beneath Nyos volcano (Cameroon volcanic line) . . . . . . . . . . . . . ...40Ar-39Ar ages and petrogenesis of the Massif d’Ambre volcano, northern Madagascar . . . . . . . . . . . . . |
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