Preliminary report on the geology of northeast Obudu, Bamenda massif, southeastern Nigeria. – B. E. Ephraim , B. N. Ekwueme and I. C. Adamu
ABSTRACT
The hitherto geologically unknown area situated northeast of Obudu in southeastern Nigeria is composed dominantly of a floor of high-grade metamorphosed rock successions, which are essentially quartzo-feldspathic gneisses and schists that exhibits migmatitic characteristics. These assemblages are intruded at various locations by prominent exposures of mostly granitic and subordinate gabbroic rocks that have also been metamorphosed to various grades. Other rocks mapped in the area are unmetamorphosed dolerite and xenolithic enclaves of amphibolites occurring mostly in the granite gneiss. The measured dominant foliation trend of N-S to NE-SW direction, associated with the predominantly northwesterly dip directions in the rocks of the area indicate that most of these rocks were probably affected by the Pan-African thermotectonic events (550 ±100 Ma). The proximity of the area of study to western Cameroon and the similarities of the rocks of northeast Obudu area to basement units occurring in the Western Cameroon Domain permit the consideration of northeast Obudu area as a westward prolongation of Precambrian terrains of Cameroon into southeastern Nigeria.
Keywords: Northeast Obudu, amphibolites, granite, migmatite, metagabbro