The Cameroon Line: A Review

Abstract

Since the work of Von Baumann (1887) the Cameroon Line (Fig. 1) is known as a major geological feature in Central Africa. The Cameroon Line is an alignment of oceanic and continental volcanic massifs and of anorogenic plutonic complexes trending N 30° from Pagalu Island to Lake Chad (Geze 1941). It is now considered (Moreau et al. 1987b) as a Pan-African lineament more or less permanently rejuvenated from the Late Precambrian to the Present. The oceanic segment of the Cameroon Line is composed of the four volcanic islands of the Gulf of Guinea (Pagalu, formerly Annobon, Sao Tome, Principe and Bioko, formerly Fernando Poo). Its continental segment is represented by the volcanic massifs of Mount Cameroon, Rumpi, Manengouba, Bambouto, Oku and the volcanic outpourings of the Benue Valley (West of Garoua) and of the Kapsiki Plateau and by more than 60 anorogenic plutonic complexes from Mount Koupe to Waza. Extensions of the Line to Ascension (Gouhier et al. 1974) or to Saint-Helena (Tyrrell 1934; Furon 1953, 1968; Vincent 1970b) for the oceanic segment, or to Tibesti (Furon 1953, 1968; Vincent 1970b) or Southeastern Libya (Tempier and Lasserre 1980) for the continental one have been suggested. The Cameroon Line has also been described as a Y-shaped zone (Fitton 1980, 1983) with the trunk represented by a line from Pagalu to Mt Oku and the branches by the Adamawa and the Biu plateaux.