Structural and Petrologic Studies of Bumaji Area, Southeastern Nigeria

Author(s): Charles C. Sholokwu, Ndukauba Egesi

The study area is part of the Basement Complex of Southeastern Nigeria. The major rock units in the area comprises of intrusives (pegmatites, dolerites and charnockites), and the host metamorphic rocks are; quartzites, migmatites, schists, and biotite gneiss. Structural evidence shows that the rocks are deformed and were intruded by the magmatic rocks. The metamorphic rocks are strongly deformed in N-S to NE-SW direction. The charnockites is composed of quartz, 32%, plagioclase, 25%, K-feldspar, 20%, hornblende, 15% and other accessory minerals. The dolerite consists of olivine, 30%, biotite, 17% and hornblende, 16%. It shows ophitic texture. Schist and migmatite indicatess faults, fractures, mineral lineations and planar features. Variation in structural trend and mineralogical composition of the metamorphic rocks is due to the series of deformational activities; metamorphism and magmatism, which has affected the rocks during geologic time. The small scale geological structures which were used to interpret large scale structures, are of the size a field outcrop scale of 1cm to 10km of the district geological features.

Rocks, Deformation, Metamorphism, Intrusions, Structures, Basement SE, Nigeria

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