The mapped area falls within the Benue
trough The oldest sedimentary rocks in Nigeria is in this trough and they
are of lower cretaceous age. The Benue trough is one of the seven main
sedimentary structural features in the SE-NE Nigeria.
Its developed during the separation of South America and Africa and the opening
of South Atlantic ocean at the site of the
triple junction. Olade (1976) describe the basin as the failed arm of the rift
system (aulacogen) that developed by progressive mantle plume activities and
accompanied by sedimentation.
According to
Offodile (1976), the Benue trough, geological consist of a linear stretch of
sedimentary basin running form about the present confluence of the Niger and
Benue Rivers to the Northeast and
bounded by the basement complex areas in the North
and South of the river Benue. Kogbe (1981) noted several depositional cycles, which
resulted in the deposition of diverse sedimentary rocks of varied composition
and age. These sediments occupied up to 6,000m of marine and fluvial celtaic
sediments that have been compressionally folded in non-orogenic shield
environment. Mineralization in the Benue Trough is restricted to Cretaceous
rocks found in about 48,000km area of the trough (Orazulike, 1994). Lead-zinc
ore has been mined in the trough in addition to salts, barites, and other
deposits of importance. Galena
and sphaterite are found in the Albian carbonaceous shales, the Abakaliki shale
of the Asu-River Group (Reyment, 1965).