Integrated Geological and Geophysical Data as an Aid to Surface Geological Mapping and Mineral Exploration of the Ibillo-Okene Area SouthWest Nigeria

Abstract

Ibillo-Okene area located at the northern fringe of the Igarra Schist belt, is a part of the Basement Complex rocks of southwest Nigeria. Aerogeophysical Datasets were used in conjunction with field data in order to interpret the geology and structure of this area. Five major lithological units were identified in the study area including migmatites, biotite schist, quartz schist, granite gneiss, and calc silicate gneiss which is associated with marble. Three episodes of deformation in the study area include that captured by relics of meta-pelitic (basic) rocks caught up (as xenoliths) in the main phase gneisses, that which produced the fabric in the main phase gneisses as well as metasedimentary rocks and that which is associated with Pan-African orogenic event which apparently modified the earlier two. Orientation of dominant foliation planes gives a general outline of the closure of the ancient basin; late-stage, brittle-ductile deformation resulted in the compression of this basin and subsequent faulting. This NW-SE trending fault reported in the present study area is an extension of a gold-bearing fault reported south, around Dagbala-Atte area. Also, metasedimentary rocks found here are associated with marble just like their counterpart in the southern parts of the Igarra schist belt.