Integrated Geological Aeromagnetic and Remote Sensing Datasets in Litho-Structural Mapping of Basement Rocks in Otan-Ayegbaju and Environs, Southwestern Nigeria

Abstract

This study presents an innovative approach to litho-structural mapping of basement rocks in Otan-Ayegbaju area of Southwestern Nigeria by integrating advanced satellite technology and geophysical methods. The primary objective is to enhance the understanding of geological formations and identify potential mineralized zones. High-resolution data from Landsat 8 OLI, Shuttle Radar Topographic Mission and aeromagnetic surveys were analyzed using advanced techniques including Principal Component Analysis (PCA), First Vertical Derivative, and Euler deconvolution to delineate lineaments with structural trends and potential mineralized zones.  Ground truthing shows that the area is dominated by porphyritic granite, quartz-schist and other rock types such as amphibole schist, talc schist, pegmatite and diorite. Lineament studies reveal that NE-SW, NS-EW and ENE-WSW structural orientation dominate the area. Total magnetic intensity value ranges from 46.6nT to 119.5nT, suggesting contrast magnetic susceptibilities and variation in structural trends of the lithology in the area. Mineralization in Otan-Ayegbaju area is structurally controlled as zones where lineaments and strong magnetic anomalies coincide at the Northeast, central and Southwest are the most promising targets for mineral exploration. Euler deconvolution analysis indicates shallow and deep-seated faults which range from < 200m to > 1600m. This is peculiar to epithermal ore processes which can result to the formation of vein hosted epithermal deposits like gold, electrum, argentite, and chalcopyrite. The integration of geophysical and remote sensing methods proves to be a highly effective approach to enhance geological mapping of structurally altered zones especially in rugged terrains and lays the foundation for future exploration efforts in the area.