Petrochemistry and petrogenesis of the Precambrian Basement Complex rocks around Akungba-Akoko, southwestern Nigeria

Ogunyele, Abimbola Chris; Oluwajana, Oladotun Afolabi; Ehinola, Iyanuoluwa Queen; Ameh, Blessing Ene; Salaudeen, Toheeb Akande

doi:10.2478/rmzmag-2019-0036

Cited by 13 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This rock had undergone a series of tectonic deformations, which created both simple and complex structures comprising of folds, fractures and sheared zones. Since this granite gneiss is similar in forms, textures and colours to that found around Akungba-Akoko, it is likely that it has a similar chemical composition as reported in (Ogunyele et al 2019).…”

Section: Location and Geological Settingsupporting

confidence: 61%

“…Precambrian Basement Complex of Nigeria is located within the Pan-African Trans-Saharan mobile belt between the West African and Congo Cratons and to the south of the Tuareg Shield (Woakes et al 1987;Kroner et al 2001 Etioro-Akoko with its environs is underlain by the Migmatite-Gneiss Complex of the Precambrian Basement rocks of southwestern Nigeria. The granite gneissic rock is the predominant lithological unit in the study area as observed from detailed field geological mapping, and it is shown in Figure 3 (geological map of Etioro-Akoko combined with the geological map of Akungba-Akoko in the work of Ogunyele et al 2019). The granite gneiss of Etioro-Akoko, which extends to other parts of Akungba-Akoko area is weakly to moderately foliated, light grey, medium to coarse-grained in nature, with a blastoporphyritic to porphyroblastic fabric based on field observation.…”

Section: Location and Geological Settingmentioning

confidence: 93%

See 1 more Smart Citation

Subsurface geological, hydrogeophysical and engineering characterisation of Etioro-Akoko, southwestern Nigeria, using electrical resistivity tomography

Akingboye

Osazuwa

2021

NRIAG Journal of Astronomy and Geophysics

View full text Add to dashboard Cite

Noninvasive geoelectrical subsurface characterisation provides screening of the earth medium to resolve complexity in subsurface geology caused by inhomogeneity of the overburden strata and bedrock architectures. The subsurface geological, hydrogeophysical and engineering conditions of Etioro-Akoko, southwestern Nigeria, were investigated using electrical resistivity tomography (ERT). This was aimed at unravelling the hydrogeodynamic and litho-structural complexity that are responsible for low groundwater yield in wells/boreholes and foundation failures. Field 2D resistivity data sets of the study area were inverted and used to produce geotomographic models for detailed insights into the complex subsurface geological setting. Results of the 2D resistivity inverted models showed three to four distinct layers; the topsoil, weathered layer, partially weathered/fractured bedrock and fresh bedrock. Bedrock structures occasioned by fracturing and deep weathering of the bedrock were delineated with resistivities and thicknesses ranging from 40 to 950 Ωm and 10-25 m, respectively. The fracture systems; F1, F2, F3, F4 and F5 in NW-SE, NNW-SSE, NE-SW and ENE-WSW orientations act as the major groundwater collecting centres in the area. The orientations and geometries of these geologic features are the manifestations of structural deformation of the underlying geology. Fourteen hand-dug well and four borehole points were proposed based on the ERT results. Conversely, the localised bedrock structures and oscillating bedrock topography were suggestive of potential threats to the foundations of engineering structures in the studied area. Reinforcement of concrete foundations at certain sites where ERT suggested that the underlying strata were not capable of bearing loads was recommended as well. This study has offered a detailed understanding of the subsurface geological disposition for sustainable groundwater development and siting of durable civil engineering structures in the studied area and other areas with typical complex geological settings.

show abstract

Section: Location and Geological Settingsupporting

confidence: 61%

Section: Location and Geological Settingmentioning

confidence: 93%

Subsurface geological, hydrogeophysical and engineering characterisation of Etioro-Akoko, southwestern Nigeria, using electrical resistivity tomography

Akingboye

Osazuwa

2021

NRIAG Journal of Astronomy and Geophysics

View full text Add to dashboard Cite

show abstract

“…Other tarred and untarred roads found around connect one quarter to another, thus providing good accessibility to most parts of the area. The town is underlain by Precambrian Basement rocks of the southwestern Nigeria with migmatites and gneiss constituting the two dominant rock types [20] and [21] in Figure 3. The rocks outcrop as lowland and domy ridges trending E-W.…”

Section: Description Of the Study Environmentmentioning

confidence: 99%

Geophysical and Borehole Studies for Optimum Drilling Depth and Groundwater Yields in a Typical Basement Terrain, South-western Nigeria

Mohammed¹

2022

IJASRE

View full text Add to dashboard Cite

This study embraced the integration of 20 vertical electrical sounding (VES) and 15 borehole log datasets to determine optimum drilling depth and yields of boreholes in part of Akungba -Akoko, southwestern Nigeria. Resistivity soundings interpretation was aided by borehole litho-geologic information. Results revealed line-to-line correlation of three-five distinct subsurface geological/geoelectrical profiles to include; the topsoil, sandy/clayey weathered/partially weathered basement, fractured basement/ fresh basement. The thickness and resistivity of the weathered basement column ranged between 1.9 -15.8 m and 26 -579 ohm-m respectively. Regoliths, with a mean thickness of 9.97 m (approximately 10 m), constituted thin aquitards developed on the basement. The combination of regoliths and the near-surfaced interbedding multiple thin layers of the fractured basement up to 30 m depths gave lower yields of less than 1.0 l/s to shallow boreholes. These drilled depths were those constrained at the instance of the poor index of lithologies exhibited by the sounding results, thus rendering the thin fractured beds undifferentiated from the thick resistive basement. Depths for high groundwater yields of 1.15 -2.56 l/s were recorded for deeper borehole depths of 46 -70 m, with a mean of 55.3 m. It can therefore be concluded that optimum groundwater yields not less than 2.0 l/s were recorded for boreholes that took full advantage of the weathered lithology and structures at a deeper depths of 60 -65 m. The study further asserts that beyond the mean depth of 55.3 m, the deposits become more compacted, low fracture density with groundwater yields wholly retarded, thereby leaving the optimum drilling depth to 70 m, as the target of most groundwater prospects for optimum yields of deeper boreholes in the area.

show abstract

“…The Southwestern Basement Complex of Nigeria comprises three major rock suites, namely the Migmatite-Gneiss Complex, the Schist belt, and the Older Granitoid. The Migmatite-Gneiss Complex rocks range in age from Neoproterozoic to Paleoproterozoic and Archean [20,21,22]; the Neoproterozoic Schist Belts, consisting of low-grade, younger metasedimentary, and metavolcanic rocks with ages ranging between 690 and 489 Ma [21,24,25], and the Pan-African Older Granites, which intruded the two earlier lithologies, have ages ranging between 650 and 580 Ma [25,26,27,28].…”

Section: Location and Geological Setting Of The Study Areamentioning

confidence: 99%

“…The Migmatite-Gneiss Complex rocks in the area are typically [31]). (c) Geological map of Akungba-Akoko and its surroundings in Ondo State, southwestern Nigeria, modified after [27]. migmatite, granite gneiss, biotite gneiss, and granitoids (charnockite and granite).…”

Section: Location and Geological Setting Of The Study Areamentioning

confidence: 99%

Geohydraulic characteristics and groundwater vulnerability assessment of tropically weathered and fractured gneissic aquifers using combined georesistivity and geostatistical methods

Akingboye

2022

J. Nig. Soc. Phys. Sci.

View full text Add to dashboard Cite

Sustainable groundwater yield in aquifers depends on the protective capacity of the subsurface lithologies and conduit systems. Electrical resistivity tomography (ERT) and its Schlumberger vertical electrical sounding (VES) technique were employed to assess the groundwater yield of aquifer units and their vulnerability to contaminants in Araromi (Akungba-Akoko), southwestern Nigeria. Geohydraulic parameters: aquifer resistivity (\rho0), hydraulic conductivity (K), transmissivity (T), permeability (\Psi), hydraulic resistance (KR), and longitudinal conductance (S) were also evaluated. In addition, regression analysis was utilized to establish the empirical relationships between the K and other geohydraulic parameters, with their percentage contributions to posing vulnerability risk. The georesistivity results revealed four distinct layers: topsoil, weathered layer, partially weathered/fractured bedrock unit, and fresh bedrock. The K model regression-assisted analysis showed that the \rho, T, \Psi, and S contributed about 97.8%, 14%, 99.9%, and 11.5%, respectively, to the estimated aquifers’ K values for the study area. Except for T and S, the regression results had moderate to strong positive correlations with K; hence, this illuminates the essentiality of K in assessing groundwater potential and vulnerability. The aquifer units have low to moderate groundwater yield based on T values (1.67-17.57 m/day) caused by the generally thin overburden (<4 m). However, the deep-weathered and fractured aquifer units with depths ranging from 39-55 m could supply high groundwater yield for sustainable abstraction. The estimated S values (0.0226-0.1926 mhos) for aquifer protective capacity ratings rated the aquifer units in the area as poor to weak. Based on the estimated low logarithm of KR (log KR) values of 0.79-2.25 years, these aquifers have extremely high to moderate aquifer vulnerability index. As a result, prospective wells/boreholes in the study area and settings with similar geohydraulic and vulnerability characteristics should be developed adequately to prevent the infiltration of surface contaminants for potable groundwater abstraction.

show abstract

Petrochemistry and petrogenesis of the Precambrian Basement Complex rocks around Akungba-Akoko, southwestern Nigeria

Cited by 13 publications

References 17 publications

Subsurface geological, hydrogeophysical and engineering characterisation of Etioro-Akoko, southwestern Nigeria, using electrical resistivity tomography

Subsurface geological, hydrogeophysical and engineering characterisation of Etioro-Akoko, southwestern Nigeria, using electrical resistivity tomography

Geophysical and Borehole Studies for Optimum Drilling Depth and Groundwater Yields in a Typical Basement Terrain, South-western Nigeria

Geohydraulic characteristics and groundwater vulnerability assessment of tropically weathered and fractured gneissic aquifers using combined georesistivity and geostatistical methods

Contact Info

Product

Resources

About