Geothermal and radioactive heat studies of parts of southern Bida basin, Nigeria and the surrounding basement rocks

Abstract

Aeromagnetic and aeroradiometric data covering parts of southern Bida basin, Nigeria and the surrounding basement rocks were processed and interpreted. The research covered both basin and basement rock sections, and was aimed at determining the geothermal heat flow and radioactive heat characteristics of the survey area. The number of data points used for analysis were 2,937, obtained from the digitization of eleven ½ degrees by ½ degrees contour maps. Data processing methods used in the study include determination of heat from radiometric data, regional-residual separation of the total magnetic intensity data, determination of depth-to-top and depth-to-bottom of magnetic sources and estimation of field scaling exponent using the Fractal technique. The research results gave geothermal heat flow values ranging from 69.167 mWm -2 to 124.821 mWm -2 with an average value of 90.959 mWm -2 and radioactive heat values ranging from 0.91 to 4.53 µW/m 3 with an average value of 2.28 µW/m 3 . Deductions made from the survey are, the field scaling exponent varies linearly with depth of downward continuation and Katakwa is a prospect area for geothermal heat.

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“…The 2D modeling of magnetic anomalies in the study area reveal the existence of deep seated faults which may have controlled the ranges from 0.07 km to 0.42 km with an average depth of 0.21 km. Megwara and Udensi [1] carried out structural analysis over parts of southern Bida basin and the surrounding basement rocks using aeromagnetic data for the purposes of highlighting linear structures, and deduce the effects of such features on the tectonic events in their survey area. Their results using Euler deconvolution method show that depth to magnetic sources ranges from 0.01 km to 0.51 km with an average value of 0.128 km.…”

“…The three elements were combined to form a total count map and rock unit boundaries were clearly separated by geo-referencing and digitizing the geological map of the study area in order to show each rock unit present and the concentration of radioelements. The authors analyzed the radiogenic heat using the calculation of ratios from the three radio-elements: Potassium (%), Uranium (ppm), and Thorium (ppm) using a similar method of Salem, et al [26] and Megwara, et al [1]. Similarly, the radiogenic heat values were also calculated from the energy released from the Alpha, Beta and Gamma decay of rocks [27] with the aid of an empirical equation by Rybach [28].…”

“…Among these natural resources, hydrocarbon has been of great interest and had contributed immensely to the economy of the country. Magnetic method has been deployed sufficiently in been useful in a variety of ways, such as the provision of the third dimension to surface mapping and sampling, to improve a particular aspect of data, and integrate with other geoscience and ge-ographical data [1]. Accordingly, the ultimate goal of using the two methods is in the production of an interpretation which highlights one or more speci-fic problems that provide a reasonable robust and correct geological depiction.…”

“…Accordingly, the ultimate goal of using the two methods is in the production of an interpretation which highlights one or more speci-fic problems that provide a reasonable robust and correct geological depiction. Some of these pro-blems are; survey of hydrocarbon, investigation of magnetic and radiometric minerals, exploration of geothermal and radioactive heat, demarcation of structures and alteration under a cover of overbur-den or water [1]. Geoscientists, especially in Nigeria have conduc-ted several kinds of research in different basins and basement of the country using magnetic and radiometric methods.…”

Correlation and mapping of geothermal and radioactive heat production from the Anambra Basin, Nigeria

“…In this research work, Curie point depth was used to calculate the geothermal heat flow because of its importance in earth science (Artemieva et al, 2001;Megwara et al, 2012). The radioactive heat map was interpreted to know productive area based on the geographic projection of important towns.…”