Browsing by Author "Rafiu, A. A"

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    Estimating the Heat Flow, Geothermal Gradient and Radiogenic Heat within the Young Granites of Jos Plateau North Central Nigeria
    (University of Tehran Press, 2024-02) Adetona, A. A; Rafiu, A. A; Aliyu, B. Sh; John, M. K; Kwaghhua, I. F
    Both aeromagnetic and radiometric data were used to evaluate the Curie point depth and radiogenic heat production (RHP) of the young granitic regions of the Jos Plateau. An area of 55 by 110 square kilometers is bounded by latitude 9°30' to 10°00' N and longitude 8°30' to 9°30' E in central Nigeria. The magnetic data was subjected to spectral analysis to obtain the Curie depth, which was subsequently used to evaluate the geothermal gradient and heat flow for the area. Also, the concentration of radioelements (potassium, thorium and uranium) and the average density of the in-situ rock were used to estimate the radiogenic heat production at each point where the Curie point was evaluated. The heat flow in the study area ranges from 10 to 165.5 mW/m2 with an average value of 111.00 mW/m2. The regions with anomalous heat flow of 165.5 mW/m2 are located around Bowon Dodo, Dan Tsofo, Kadunu, Gimi, Kaura and Zankan in plateau state. The geothermal gradient values range from 5 to 68 °C/Km with an average of 26.16 °C/Km. The radiometric data analysis resulted in radiogenic heat values ranging from 0.4 µWm3 to 6 µW/m3 with an average radiogenic heat value of 3.36 µW/m3. Both analyses revealed that regions such as Ataka, Gimi, Jimjim and Pari could be investigated for geothermal energy potential. The high concentration of uranium, thorium and potassium associated with the study area is likely due to the weathering of the in-situ granitic basement rocks.
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    Integrated Geophysical Investigation for Potential Gold Mineralised Zone within Lower Part of Zuru Schist Belts, NW Nigeria
    (Nigerian Institute of Physics, 2024) Augie, A. I; Salako, K. A; Rafiu, A. A; Jimoh, M. O
    The study began with a reconnaissance survey that used high-resolution aeromagnetic data of the study area to identify suitable structure zones with the potential to trap mineral resources within the context of the gold exploration target. The findings of magnetic studies were followed up with detailed investigations using 2D electrical resistivity tomography (ERT) and induced polorisation (IP) techniques to reveal further details about gold mineral zones and other lithological boundaries. The airborne magnetic data of sheet 118_Yelwa was obtained from the NGSA; these datasets were processed and analyzed using Oasis Montaj's first vertical derivative (FVD) and center for exploration targeting (CET) techniques. Results of FVD and CET grid anomalies show that regions of major magnetic structures (lineaments) are associated with granite gneiss, migmatitic augen gneiss, and medium to coarse-grained biotite when compared to the geological settings of the area. The zones of major structures obtained in this study coincided with previous magnetic studies of the area, located in the eastern parts of Ngaski, Yauri (Yelwa), Shanga, Agwara, as well as Magama's northwest region. Some of the regions for lineament (in the eastern part of Ngaski/Yauri) were investigated further with 2D ERT and IP detailed geophysical methods in a dipole-dipole configuration. The results of geoelectric techniques along profiles 1, 2, and 3 identified the major gold mineralisation potential zones, which were labeled A1, A2, and A3. These regions have low/high resistivity (1.6 to 459 Ωm/1889 to 7773 Ωm) and chargeability signatures (≥ 20 msec), and could thus be interpreted as potential target zones for metallic mineral exploration, particularly gold mineralisation. The regions are located in the northern Mararraba and southwest of the Jinsani areas of Kebbi State. The results of integrated geophysical methods have produced updated structural features of the regions, as well as a database containing precise locations, lateral lengths, thicknesses, and depths for prospective gold mineralisation zones. This database could assist the miner/explorer in locating the potential zone of gold mineralisation.