Application of Geophysical and Geostatistical Methods in the estimation of clay deposit Reserve of Idofe and environs, southwestern, Nigeria (original) (raw)

Clay minerals are among the world’s most important and useful industrial minerals. Conductance, transmissivity and corrosity are some physical parameters for determining quality clay. Four (4) clay deposit sites in Kaffin-Koro, Dutse, Dogon-Ruwa and Kushikoko were investigated to evaluate corrosivity, the longitudinal conductance and transmissivity to determine the clay quality. Electrical resistivity method employing Schlumberger electrode array was used to determine the thicknesses and depths of the subsurface strata while Interpex 1xD software was used to interpret the data. Three (3) to four (4) layer earth models were delineated. Kaffin-Koro and Dutse showed three layer models while Dogon-Ruwa and Kushikoko revealed four layers. Moderate clay content was found in Kaffin-Koro in the second layer with longitudinal conductance value of 0.4780 siemens and thickness 0.770m at depth of 1.17m Dogon-Ruwa also had moderate clay content in the third layer with conductance value of 0.237 ...

Clay resources exploration and exploitation has been on a steady increase in a bid to satisfy a growing mineral resource utilization industry. This necessitated a preliminary geophysical investigation of Orin-Ekiti clay deposit aimed at investigating the subsurface lithology, make deductions on the depth and thickness of any clay deposit encountered in the region as well as implications on possible industrial and engineering uses respectively and finally suggest possible areas for groundwater prospecting as a solution to the prevailing need for water in the area. Prospecting for clay deposits in the study area employed the vertical electrical sounding (VES) technique of the electrical resistivity geophysical survey method utilizing Schlumberger array. Six (6) VES at six (6) stations in the study area were carried out with maximum electrode spacing of 55.0m. Preliminary VES results revealed three main sounding curves namely HK (VES 1), KH (VES 2, VES 3 and VES 4) and K (VES 5 and VES 6). Indication of three to four geoelectric layers representing subsurface lithological formations was observed namely the top soil (0.5-1.9m), sandy clay (2.2m), compacted lateritic clay/hardpan (2.2-10.8m), weathered basement {clayey-7.1 m and above, clayey sand (4.2-7.4m)}, fractured basement (9.2 m and above) and fresh basement (9.9m and above). Preliminary assessment from 2D maps and 3D models indicates layer 2 of the geoelectric sections corresponding to the lateritic hardpan formation have moderate to high potential while the weathered clayey zone (layer 3) have low to moderate potential for future mining purposes. Groundwater potential in the area is rated low to medium based on overburden thickness {VES 5 (>12.4m) and VES 6 (>8.4m)} and clayey sand formation composition {VES 3 (>9.2m) and VES 4(>11.4m)} although the presence of fractured basement of undetermined thickness in VES 3 and VES 4 could significantly increase the odds. Any engineering construction project in the area would have to take into consideration the considerable thickness of the clay layers (≥ 10.8m) during planning and execution.

This study involves delineation of clay deposits in Agbonmwoba village area of Obaretin town, Edo state using 2D geo-electrical resistivity tomography technique to image the extent and economic quantity of the deposit, in order to appraise its commercial viability. The Wenner-Schlumberger electrode configuration was employed in five different locations within the study area, and a total of ten (10) Wenner-Schlumberger soundings were acquired in the area with a spread length of 200m along each traverse. The field data was inverted using the Earth Imager 2D inversion software program. Low resistivity geologic formations (ρ 30m at lateral spreads of 20-80m and 130-160m respectively. In TR8 clay deposit was imaged at 4m from the surface. In TR9 clay deposit was imaged at 8.9-17.9m at lateral spread of 90-110m and in TR10 clay deposit was imaged at 17.9-20m at lateral spread of 40m and 100-120m respectively. This results show that clay deposits imaged along traverses 1, 2, 4, 5, 9, and 1...

Abstract Hydromorphic soil otherwise known as valley bottom soils have potentials for high and sustainable agricultural production due to their inherent characteristics of shallow water, deposition and accumulation of organic matter and residual available moisture for farming. However, the hydromorphic soils has been little studied and hence under-utilized in Nigeria. An integrated geophysical investigation was conducted on a hydromorphic soil at Ilora, southwestern Nigeria to determine subsurface geometry, lithologies and water table in relation to its agricultural significance. The non-invasive geophysical methods which include GSSI Ground Penetrating Radar (GPR) equipment with 400 MH antennas system and one dimensional electric resistivity survey involving Vertical Electrical Sounding (VES) were employed. GPR data were collected on seventeen profiles with eleven in the W – E direction and six in N – S direction at different lengths with 20 m inter profile spacing. Twenty eight VES were conducted within the study area with current electrode ranging from 2.0 m to maximum of 150 m using the convectional Schlumberger array. The GPR data was processed using Radan 7 software while the VES data was subjected to iteration using WINDRESIS software. Three test pits were dug to a depth of 1 m to correlate the GPR and Electrical result and for ground truthing. The GPR radar sections show three different horizons which include: sub-parallel reflections horizon assumed to be the reworked topsoil with thickness ranging from 0.2-0.3 m, low amplitude continuous and weak reflections horizon (typical of clayey formation) indicating attenuated signal because of high moisture content with a thickness range of 0.9 - 1.4 m and multiple chaotic, non-parallel reflectors horizon. The VES results show system of two to four geo-electric layers comprising; topsoil, saturated clay, and fractured/fresh basement. The lithologies from the test pits show loamy, silty and clayey soil of varying colour and thickness. The delineated layers for both geophysical methods show some degree of correlation. The relatively shallow depth and high water retentive capacity of the second layer accounts for its usage for farming especially at the peak of dry season. Keywords: valley bottoms, attenuation, radar sections.

Geoelectrical and geotechnical investigations were carried out to characterize soils from different locations in Ede, Osun State, Nigeria for engineering purposes. Wenner electrode configuration technique was deployed in carrying out the geoelectrical survey of about 40m for each profile. The data analysis was approached by plotting the apparent conductivity against electrode spacing (s) and the result was interpreted. The geoelectrical resistivity survey revealed locations 1 and 2 with resistivity values of 25.01-419.22ohm-m (conductivity 0.002 - 0.194 (ohm-m)-1and 5.5-1246.57 ohm-m (conductivity = 0.0002 - 0.001 (ohm-m)-1) respectively could be classified as clay. Sample 3 recorded a resistivity value of 1.00- 22,787.39 ohm-m (conductivity= 0.00004- 1.00 (ohm-m)-1) thus, was classified as silt/sand respectively. Soil from the said different locations in Ede, Nigeria, were tested in the Laboratory for certain properties like Atterberg limits, specific gravities, sieve analysis, c...

Vertical electrical soundings (VES) and standard penetration test (SPT) were carried out at Ahmadu Bello University Phase II, Zaria, Nigeria, with the aim of correlating between transverse resistance (T) and number of blows per counts (N-value) for foundation studies. Two (2) SPT and VES using Schlumberger electrodes array, were conducted within the study area. The VES data acquired from the field were processed and interpreted using AGI earth imager 1D software. Borehole data of exact point, where the VES was carried out were used for calibration. The results obtained from the VES depicts that the depth to basement values ranges between 6.5 and 8.0 m which agree with the borehole data obtained from the SPT results. The results of resistivities and thickness obtained from the VES curve were used to compute transverse resistance. The transverse resistance was used to correlate with the N-values obtained from SPT data. It was observed that the correlation of transverse resistance and N-value was linear and highly positive. The linear relationship that was established between the two parameters can be used to determine the soil strength at any point within the area of study.

Geophysical method using 1-D and 2-D resistivity probing techniques and Geotechnical method using Cone Penetrometer Test (CPT) has been integrated to delineate the characteristics of subsurface layers at the School of Management and Library complex areas of Lagos State Polytechnic, Ikorodu. The 1-D vertical electrical resistivity sounding data (VES) and 2-D resistivity data using the Wenner array were acquired with Allied Ohmega Resistivity meter. Two 2.5 tonnes Cone Penetration Test (CPT) was considered for the work.. The VES data obtained were processed and interpreted using partial curve matching technique and 1D computer assisted forward modeling using WinResist software. The 2D data were also processed and interpreted using DiproWin software version 4.0. The interpreted results of the investigations shows that, the main lithological unit of the two areas consists of sandy clay and sand materials. In conclusions, the northern part of School of Management area consist of sandy cl...