STRUCTURAL GEOLOGICAL MAPPING OF OMU-ARAN, KWARA STATE USING REMOTE SENSING

Abstract

Lineament mapping and analyses from satellite data of Omu-Aran area provide a new, rapid and stimulating overview for regional structural (lineament) study for mineral exploration, locating of new mineral deposits and planning the development of the selected area. The structural geological mapping of Omu-Aran area, Kwara State using remote sensing was achieved by the geological mapping of the area integrated with remote sensing techniques, so as to update the geological map and produce a mineralization potential map of the area. Landsat 8-OLI, Shuttle Radar Topographic Mission (SRTM) and Sentinel imageries were acquired and processed using Principal Component Analysis (PCA) method in ENVI 4.3 software. The image was imported into ArcGIS 10.2 for further analysis. The analyzed structures were interpreted in form of lineaments which show dominant trends of NNE-SSW and E-W, less dominant is N-S direction. Statistics and rose diagrams for all the interpreted linear features acquired in the study area were also prepared. The dominant trends of NNE-SSW and E-W correspond to the general trend of Precambrian to Cambrian rocks in Nigeria, including rocks of the Basement Complex, as a result all the rock types are said to be Pan-African in age. The study further shows that the largest amount of lineaments are found on the quartzite and accounts for 40% of the total number of lineaments in the area. The study area is highly fractured, with a complex geological pattern; the most striking megascopic feature on the imageries is the ridge on the northwestern part of the study area, with prominent fold enclosure plunging northwards. Tantalite and tourmaline is mine in some areas where the lineament density is high and along the E-W lineament orientation which favour mineralization in the basement complex.