Abstract

The tectonics and impact of the Pan-African orogeny on the Hong Hills area of North Eastern Nigeria has been unraveled. This work basically used structural identification and tectonic inference to decipher the deformation episodes in this region. The results show that this area was subjected to multiple episodes of deformation and there were evidence of reworking of older structures by younger ones. Foliation, folds and dykes/vein data suggests that the metamorphic rocks in this area experienced a predominant E - W compression during the Pan - African Orogeny. Structural evidence and the presence of dominant ductile shear zones also confirm that the deformation in this region is predominantly ductile. The relatively younger granite intrusions show structural trends which are consistent with the closing periods of the Pan-African Orogeny.  Evidences show the emplacement of these plutons followed regional structural direction defined by major fold trends and rock foliation. Salient isolated features suggest the occurrence of pre Pan-African orogenic structures but there aren’t enough data or evidences to buttress this claim. From this work, we can safely say that the Hong Hills region is a complex Pan-African zone with two major episodes of deformation.

Key words: Basement complex, geological structures, pan-African deformation, pluton emplacement.