CHAPTER ONE
INTRODUCTION
The study area is situated in Akampka Local Government Area of cross river state (figure 1) and the area forms part of the Oban Massif which constitutes the basement complex of south eastern Nigeria (fig2)the area lies between latitude 050 221N and 050 261N and longitude 0080 361E and 0080 381E greenwich and covers about 72km2
The study area consist of such Mappable units of the amphibolitesfacies rocks and they include gneisses, amphibolites intruded by quartz veins, Pegmatites veins and dolerite (Rahman et al, 1981, Ekwueme, 1990)
The Oban massif is surrounded in the North by the Mamfe Embayment, in the west by the Benue trough, in the south by the Calabar flank and extending into the Cameroon in the East. The Oban Massif is overlain by cretaceous tertiary sediments of the CalabarFlank (Ekwueme, 1990)
- LOCATION AND ACCESSIBILITYThe study area is restricted toAking-Westand its environs and covers an area of land consisting of three main settlements namely, Osomba, Mankorand Aking,all in Akamkpa L.G.A of cross river state. The study area is accessible through the major road (the Calabar-EkangRoad) which extends to the Cameroonborder. Several other minor roads facilitate accessibility into various locations within the study area.
- REVIEW OF LITERATUREThe Nigerian basement complex which includes Oban massif in the southern part of Nigeria where the study area is located shows the least investigated and therefore presented as an undifferentiated basement complex in the geological map of the region (geological survey Nigeria sheet 50). Oyawoye (1964) recognized three subdivisions in the Nigeria Basement.
- Ancient Metasediments
- Gneisses, Migmatites, Older Granite
- Younger Metasediments
Rahman, (1976) also recognized four major Petrologicalunits in the Basement Complex of Nigeria as follows:
- Migmatic – gneiss – quartzite complex (Esurnean,2000ma )
- Meta-igneous rocks