Deformational History Reconstruction of Basement Complex Rocks in Okomita, Ojirami and Environs, South Western Nigeria

Abstract

Deformation histories aid in remodeling the forces related to rock formation. Hence, the objectiveof this paper as to examine the deformational history of the Basement Complex rocks in Okomita, Ojirami and Environs, South Western Nigeria using appropriate standard methods. Results of the field work embarked upon revealed that the major rocks encountered include older granite and metasediments like mica schist, quartzite and gneiss. The analysis of the structures contained in the rocks was achieved by plotting the orientation of the structures on rose diagrams and stereonet. The results show that the rocks were subjected to polyphase deformation, comprising of pre-Pan African and the Pan-African orogeny. While the Pan African orogeny left imprint of NE-SW trend as observed in all the rocks, the pre-Pan African orogeny generally has a NW-SE trend which was observed to be associated more commonly with only the metasediments.

Keywords

• Foliation; Fracture; Rose Diagram; Stereonet; Polyphase Deformation