Adedoyin, A.D.Bamigboye, O.S.Adekeye, J.I.D.Ojo, O.J.2018-10-052018-10-052013http://hdl.handle.net/123456789/1217Penetrative metamorphic tectonite fabrics, folds, and shear zones constitute the main structural elements in Koro- Egbe area. Results of field mapping, which was used to constrain the shear zone, revealed the nature of the fabrics in the grey gneiss, schist, meta-basites and the Pan African granites in the area. The development of penetrative fabrics in the large-scale sheeted rocks defines the first deformation episode, D1. The second deformation episode D2, is revealed in the horizontal asymmetric folds (Koro-Egbe folds), while a major shear-zone developeded during a post-folding phase defines the D3 event. Within the shear-zone, bodies of porphyritic biotite granite of Pan African age (600±150Ma) were strongly tectonised with a north-easterly steeply-dipping foliation. Outside the shear zone, the porphyritic granite is relatively undeformed, preserving strong igneous textures. Smaller bodies of fine-medium grained biotite granite occur within the deformed porphyritic bodies in the shearzone. It is consideredthat the petrogenesis of these smaller bodies is strongly linked with the shearing under a high geothermal condition.enDUCTILE SHEARINGREMOBILIZATIONPORPHYRITIC GRANITEKORO-EGBE AREASOUTHWESTERN NIGERIAArticle