Department of geology
ABSTRACTS
The
study area is located within latitude 050 271 4611N
and longitude 0080 431 46E, and the elevation of the
place is 156m. The major rock types encountered in the area include gneisses,
quartzite, amphibolites and marbles. These are intruded by pegmatite, quartz
vein and aplite. The latest metamorphic episode occurred during the Pan-African
Orogeny (600 ±
15ma) and the deformation left a structural trend of NS and NE-SW on the rocks.
The occurrence of NW-SE structural trend are also shown on some rocks
indicating that the Pan-African event did not completely alter earlier
structural imprints. The study area is highly forested, undulating in slope and
is a characteristic of a tropical rain forest in the area.
Chapter
One: Introduction
The
geology of southern Akor and its environs lies within the Oban Massif, a
component of the crystalline basement of Nigeria. The Nigeria crystalline
basement in turn forms a part of the African crystalline basement and covers
over 50% of the total land surface of Nigeria . The rock assemblages encountered
and identified consists of mainly schists, gneisses, Amphibolite, Charnockite,
Marble and Quartzites and pegmatite, Quartz vein and Aplite emerging as Igneous intrusive rocks. The area
mapped and studied (Akor) is predominated
by intrusive rocks and these rocks are very well exposed where the topographyis slopy along
streams and river channels.
Ekwueme
et al (1992) proposed that charnockite rock’s
occur in both the eastern and western Oban Massif. The rocks occur as large
coarse-grained, rounded and, massive bodies deformed together with the bounded
gneisses. Ekwueme (1992) has shown that the diorities and charnockite are
similar in composition and that the former may be retrogressive product of the
latter.
The occurrences of weathering and tectonic activities
were observed to have greatly affected the exposed outcrop and such effects
from wet season had deformed these outcrops to boulders with reference to their
shapes and sizes.
1.1 Location and accessibility
The
area is located in the Eastern part of Akamkpa local Government area of theCross River State of
Nigeria. It covers an estimated area of about 85sq.KM and constitutes part of
the Oban Massif of the South-eastern Nigeria. The map area is largely made up
of Ntebachot Akor. New Ntebeji and Ayip Eku all located in Akamkpa Local
Government area of Cross River state.
About
90 percent of the area is inaccessible due to thick vegetation, steep valleys
and hilly terrains. The only access road across the area is the Calabar-Ekang Road
while hunters tracks provide minimal access into the area.