Understanding if the anomalies in this context originate from bedrock or sedimentary units is essential for assessing basin structural features and depth to shallow mineral exploration targets 3.Īeromagnetic data also offer 3-Dimensional information about geological terrains as well as the plunge and dip of geological features through evaluation of gradients in the data 4. Similarly, significant improvements have also been made in the processing of aeromagnetic anomaly maps and in their integration with other data for optimum geological interpretation. Recent improvements in digital processing of remotely sensed imagery have led to higher resolution of delineation procedure of regional surface features. This makes high resolution aeromagnetic and satellite imaging techniques more appropriate for the region.Īeromagnetic survey and remote sensing methods are standard exploration techniques, which are highly suitable for mineral exploration programs 1, 2. The accessibility of lineament systems of the study area are greatly reduced due to dense vegetation in a sub-tropical and tropical region such as Nigeria. It is worth to investigate these lineaments in order to produce a detailed structural map of the region, which would be useful for localizing new mining targets within the region. The aim is to differentiate basement lineaments from sedimentary basin structures and infer regions which are viable for exploitation of gold mineralization. The gold mineralization within the study area is localized by lineament systems, which are hampered by lack of structural data. Hence, any significant and economical gold mining exploitation will therefore be associated with the basement terrain south of the studied region. The sedimentary piles of the basin (northern parts of the study area) overlying the basement mask these structural features. The southern border of the Middle Niger Basin is known to host gold mineralization which occurs with quartz veins that are associated with structural features within the northern extension of the Ife-Ilesha schist belt. The miners in their bid to located gold mineralization has resulted to random excavation of potential gold sites leading to obvious loss of land for agricultural purposes 1. The constant demand for gold has resulted in the emergence and growing rate of artisanal mining activities around the boundary of the Middle Niger Basin. The results suggest high sensitivity of fluvial network to deduced lineaments with possible significant implication for alluvial gold mineralization. The topographic maps (digital elevation model) clearly shows the surface morphology of the region under study while the resulting shaded-relief map reveal the continuity of the deduced magnetic lineaments that coincide with the valleys of River Niger which exploits zones of weakness from the lineaments.
In fact, the Ifewara shear zone appears more pronounced on the total gradient and 3-D Euler deconvolution maps, which reveal various lineaments within the shear zone. The structural patterns are directly related with tectonic episodes in the basement. These structural features correlate very well with known gold mineralized locations and also predict new zones for structurally controlled gold and associated mineralization. The structural map unravels structural features with major and minor structural trends, in addition to a prominent crustal partitioning, characterized by the Ifewara shear zone. Structural map has been produced from the integration of derivative maps to assess the pattern of surface and subsurface structural features within the studied area. The newly-produced structural map highly constrained the mineralization, which makes the study area and its periphery safe for gold exploration. Due to the lack of structural data, the gold deposits within the margins of the Middle Niger Basin were variably excavated, leading to land degradation. High resolution aeromagnetic anomaly and topographic data using enhancement filtering techniques have resulted in better understanding of the nature of structures at the margins of the Middle Niger Basin.