نوع مقاله : مقاله پژوهشی
نویسندگان
1 Department of Physics, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
2 Department of Environmental Management and Toxicology, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria
3 Lecturer, Department of Physics, Sikiru Adetona College of Education, Science and Technology, Omu-Ajose, Nigeria.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Geoscientists are interested in investigating the subsurface mineral resources, such as crude oil, through exploration of the Earth's subsurface. The availability and extent of these important commercial minerals can be ascertained by the characteristics of their geophysical properties through a geophysical survey in the area under investigation. Gravity method is non-destructive geophysical methods primarily used for locating the presence of solid minerals. This research work is aimed at using data coordinate interpolation techniques to extract information from aerogravity data obtained over Ewekoro in order to estimate the depth of the overburden thickness of the geological contact of the observed causative potential field anomaly. Hence, Source Parameter Imaging (SPI) and Euler Deconvolution Methods were applied on airborne gravity data of Ewekoro in both qualitative and quantitative approaches. The airborne gravity data sheet 260 and 279 acquired by the Bureau Gravimetrique International (BGI), through the Earth Gravity Model (EGM08) in 2008 was used. The raw gravity data were recorded in digital format of X, Y and Z representing latitude, longitude and the bouguer gravity values which was exported into Oasis Montaj software for qualitative and quantitative analysis. The datasets were gridded using the minimum curvature algorithm; regional-residual separation was carried out to remove low frequency anomalies from the total field by applying a high pass filter in sharpening the edges of the anomaly and enhancement. A Two-Dimensional Fast Fourier Transform (2-D FFT) filtering techniques was used in computing different derivatives grids. The interpolated gravity map revealed a decrease in anomaly from the SW to the NE of the study area, with an anomaly range of 15 – 19 mGal. The SPI revealed a depth range of 235 – 698 m with the deeper gravity source concentrated in the central region and shallower source discovered in the SE of the study Area. The 3D Euler depth estimates corresponding to Structural Index (SI) = 0 applied to the gravity data revealed a depth range of 132–692 m with a scattered Euler solution trending in NW, NE and SSE of the study area respectively. The results for both methods indicate an average correlation in terms of their depths. The investigation revealed Bouguer anomaly thickness of Ewekoro trends in the SW– NE with significant depth for mineral exploration. The heterogeneity of the subsurface of the study area was established, and the overburden thickness of Ewekoro trending in the NNE – NNW with an appreciable depth to harbour mineral resources.
کلیدواژهها [English]
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