Geological Nature Research Articles

Structural interpretation of the basement beneath the Southern Desert of Iraq based on aeromagnetic data

The Southern Desert (SD) of Iraq is located in the southernmost region of Iraq and is tectonically located on the stable part (proximal domain) of the Arabian Platform. The area is characterized by a considerable thickness of nonmagnetic Phanerozoic sediments overlying a reworked Proterozoic basement. Due to the intense nature of the karst near-surface geology, the basement has neither been seismically imaged nor drilled. In such situations, potential field (gravity and magnetic) exploration methods can often help to identify and map the deep structure of the basement. Here, the aeromagnetic field data, which cover all of the SD, are used to determine the structure and approximate depth of the basement. We use the combined results of the tilt derivative and phase preserving dynamic range compression (PPDRC) methods to qualitatively delineate the main basement structures and then use the source parameter imaging (SPI), tilt-depth (TD), and finite SPI (FSPI) methods to determine the basement depths. The qualitative interpretation of the tilt derivative and PPDRC methods identifies three north–south to northeast–southwest-trending linear negative anomalies that could represent extensional grabens in the basement surface. These grabens divide the basement into three blocks: the northwest block, the central block, and the southeast block. The magnetic anomalies over the basement blocks suggest that the northwest and central blocks are cut by a set of north–south to north-northwest–south-southeast and northeast–southwest faults. Depth estimation methods over the uplifted blocks have minimum depths between 4 and 5 km, whereas, over the graben, the depths range from 7 km to in excess of 12 km. The FSPI method, unlike the SPI and TD methods that use an infinite depth source body, gives depths generally deeper by up to 1.1 km if the assumed Curie-point depth is 21 km. A more realistic Curie-point depth of 32 km is used in the final interpretation model. These inferred basement blocks, grabens, and subbasin structures agree in general with the regional structures associated with the Arabian Peninsula and could provide an important framework for developing future hydrocarbon exploration strategies of the SD.

Space performance assessment of traditional houses in Akre

ABSTRACT The complex natural and geological structure of cities affects buildings’ spatial structure in terms of the forms of spatial configuration adopted in the design. Spatial structure affects buildings’ space performance in several aspects, such as privacy and accessibility, which are the most significant indicators of residential houses’ functional performance. Akre, a treasured, historical city in Iraqi Kurdistan, is characterised by a complex and distinct geological nature, and its residential part contains numerous traditional houses that deserve analysis. This study employed both a qualitative approach – via case study plan preparations and photographic documentation – and a quantitative approach, utilising space syntax tools. The results were analysed with the statistical program SPSS and show three types of spatial configuration in the residential part (linear, central and cluster); each type has a different and effective impact on the achievement of space performance in terms of privacy and accessibility. The study concludes that the linear type represents the most private typology, followed by the cluster and then the central type. The centralised typology is the most connected and accessible to different spaces within the residential unit, followed by the cluster type and the linear type, with a significant difference.

Landslide susceptibility assessment along the Red Sea Coast in Egypt, based on multi-criteria spatial analysis and GIS techniques

The Egyptian Red Sea coast, a mountainous coastal region, is periodically exposed to landslide that cause severe man and economic losses. That is due to its geological, hydrogeomorphological, and seismological nature. This research aims to map landslide susceptibility in the study area using a multi-criteria overlay analysis approach. Slopes, elevations, aspects, curvature, lineaments, faults, earthquakes, rainfall, stream network, and rock units are the factors used to derive the landslide's susceptibility map. The data were obtained from research organizations and open-source geospatial platforms. The landslide susceptibility map of the area under investigation ranges from low to high as follows: 1) low (23 %), 2) moderate (43 %), and 3) high (34 %) from total area. The used model is validated using direct field check and statistical analysis by Receiver operating characteristic (ROC) curve test 40 landslides events. Based on ROC, the multi-criteria overlay analysis approach can predict landslides by 82 % at a 95 % confidence level. The leading causes of landslides are geological, topographical, hydrogeomorphological, and seismological. For long-term development, the study's findings would assist decision-makers in lowering the risks connected with landslides in the areas. To reduce the chance of landslides, the study recommended it is important to take into account the rugged topography of zones where landslides are likely to occur and implement rockfall protection systems like barriers, embankments, or mesh.

The 1895 Ljubljana earthquake: source parameters from inversion of macroseismic data

The 14 April 1895 (Mw 6.1, in the area of Ljubljana, Slovenia) earthquake is still not fully understood. The aim of this work is to derive information about its source from the inversion of an updated dataset of intensities (evaluated with EMS-98). This was done via automatic non-linear geophysical inversion KF-NGA, which was performed using a Niching Genetic Algorithm and has been presented in other articles. The distribution of damage caused by this earthquake is not homogeneous and often shows significant intensity differences between neighbouring sites. Statistical analysis of the intensities, epicentral distances and geologic nature of the sites suggests some site effects. Nevertheless, the resulting solution is consistent with regional seismotectonics, i.e. an almost pure dip-slip mechanism: strike 282° ± 5°, dip 38° ± 7°, rake 86° ± 9° (± 180° because of the intrinsic ambiguity of the KF-NGA-inversion). Since the rake angle is close to 90°, there is an almost perfect ambiguity between the two planes of the focal mechanism. Therefore, our solution has a Dinaric direction and could be associated either with a fault plane that dips NE or with one that dips SW.

Assessment of water quality for mountainous high-elevated spring waters using self-organized maps

It is crucial to continuously evaluate the chemistry and quality of spring waters due to human activity, climate change, and environmental contamination in high-elevated areas. A total of 58 spring waters were collected from high-elevated areas in the Hamedan province, Iran. Different spring waters were divided into 4 clusters using the self-organizing map (SOM) and K-means clustering approach. The results from SOM indicated that the electrical conductivity (EC), magnesium (Mg2+), sodium (Na+), and potassium (K+) displayed relatively similar patterns, while the distribution patterns of pH, nitrate (NO3−), and phosphorus (P) were completely different from other variables. Factor analysis supported this conclusion as well, indicating that while pH, NO3−, and P were the results of human activity, the main cations and anions came from parent rocks. The weighted arithmetic water quality index (WQI) was also calculated based on measured parameters and spring waters were primarily categorized as excellent water. Every cation was predominantly found on its free ion species. The saturation indices for all minerals were negative, indicating the dissolution of all minerals. It was concluded that the characterization of spring waters is substantially influenced by the geological nature of the aquifer rocks. Also, the background levels of NO3− and P have been identified as ecological goal levels for spring water resource management in high-elevated areas.

How can an integrated multi-method geophysical approach optimise the groundwater management in the Chalk aquifer? Case study of the Seine fault system (France, Normandy)

The Cretaceous chalk aquifer is a strategic water resource in the north of France, especially in Normandy where it faces increasing pressure in terms of its quality and availability. The effective and sustainable manage of this resource relies on a deep understanding of its complex geological and hydrogeological nature. However, modelling this hydrosystem has its limitations due to the spatial and qualitative heterogeneity of the data available. The integration of geophysical data using various methods and scales has improved the geological knowledge by identifying the different chalk formation and highlighting the geometry of the Seine fault system near Rouen. Geophysical analysis has revealed highly complex fault geometries in this area and clarified their impact on the chalk formations. Additionally, it has provided detailed information about the vertical heterogeneity of the chalk, both geologically and hydrogeologically. This new knowledge feeds into the existing 3-D regional geological model, especially in areas with limited data. Supporting hydrogeological modelling, this updated model has already enabled to drill new boreholes. In the future, it will contribute to a better understanding and management of groundwater resources in this region.

Hydrogeological characterization of Settat Ben Ahmed plateau aquifer (Central Morocco)

This study aims to determine groundwater dynamic and hydrochemistry for a better understanding of a hydrogeological unity of sedimentary rock to learn about chemical processes and water quality of Settat Ben Ahmed plateau aquifer. The findings reveal the chemical facies change according to the depth and geological nature of the aquifer captured. Samples of deeper point captured upstream and from Cenomano-Turonien limestones are HCO3-Ca-Mg type and account for lowest electric conductivity (EC) values. However, samples of shallow points and downstream are Cl-SO4-Ca with important EC values.

Simulation of excess lifetime cancer risk due to the presence of radon in groundwater in Wamba town of Wamba local government area, Nasarawa state, Nigeria

The measurements of Radon concentration in ten groundwater (4-wells and 6-boreholes) from Wamba town of Wamba Local Government Area of Nigeria had been carried out. The annual effective dose (AED) and the Excess Lifetime Cancer Risk (ELCR) due to ingestion of the groundwater was established to ascertain the risk outcome from the samples. Radon concentration was detected using RAD7. The minimum Radon concentration was 0.146 Bql-1 while the maximum was 0.474 Bql-1 with mean average of 0.3134 Bql-1 which are within the United States Environmental Protection Agencies (USEPA) 11.1 Bq/L recommendation. Moreso, the maximum and minimum Annual Effective Dose (AEDing) was 3.5×10^(-6) and 1.10×10^(-6) Sv/yr which are also within the 0.1 mSv/yr World Health Organization (WHO) recommendation, while the maximum and minimum Excess Lifetime Cancer Risk (ELCR) was 1.44×10^(-5) and 4.50×10^(-6) respectively. Cumulative probability simulation of the Excess Lifetime Cancer Risk (ELCR) was carried out using Oracle Crystal Ball software validated by 10 and 90% percentiles. Comparison of all the results with the European Union (EU)/World Health Organization (WHO) value of 500 Bq/L recommendation revealed that all the samples analyzed have Radon concentration below the recommended limit. The average mean Radon concentration in the ten locations from Wamba Town are within the recommended levels as confirmed by the simulation results. At 10% Probability, the highest risk was found in Event center (1.26×10^(-5)) while the lowest was found in the water sample collected from Angwan dalatu (1.05×10^(-6)) while at 90% probability the highest (1.62×10^(-5)) and lowest (1.37×10^(-6)) risk was found in the same Events center and Angwan dalatu. Though there is variation in the results based on locations which means that the concentration of Radon gas depends on the geological nature of the bedrock and generally increases with the uranium concentration in the local geology. The Excess Lifetime Cancer Risk (ELCR) dose results are far lower than the UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiations) recommended maximum contamination level of 0.003875. Therefore, no indication of any likelihood of cancer incidence as a result of waterborne radon within the studied community that may demand urgent intervention from radiological point of view.

Ochre use at Olieboomspoort, South Africa: insights into specular hematite use and collection during the Middle Stone Age

Recent excavations at Olieboomspoort (OBP) in the Waterberg Mountains of South Africa confirmed previous research at the site that highlighted an abundance of ochre in the Middle Stone Age (MSA) deposits. Here, we report on the results of an analysis of the ochre from the MSA deposits excavated in 2018–2019. Fossilised equid teeth from these deposits were recently dated to approximately 150 ka, an early date for such a sizeable ochre assemblage in southern Africa. Calcium carbonate concretions were removed from ochre pieces using hydrochloric acid. Macro- and microscopic analyses were undertaken to identify raw material types and to investigate utilisation strategies. There are 438 pieces in the assemblage and only 14 of them show definite use-traces. The predominant raw material is a micaceous, hard specular hematite, which is rare at MSA sites elsewhere in southern Africa. A preliminary investigation into the geological nature of the ochreous materials in the archaeological sample and those available in the area was performed using semi-quantitative portable X-ray fluorescence (pXRF), XRF, and inductively coupled plasma mass spectrometry (ICP-MS). Together with site formation processes, we suggest possible, primarily local sources of the ochre found in the deposits. The data do not support previous suggestions that OBP was used as an ochre caching site that may have formed part of an exchange network during the MSA. Instead, the local abundance of nodules of specular hematite within the Waterberg sandstone, the limited number of used pieces in the assemblage, and the stratigraphic context indicate a more natural, less anthropogenic explanation for the abundance of ochre at the site.

Method of choosing soils as CEB or pavement layers based on geological and environmental information and mode of treatment

During research on the geological, mineralogical, mechanical and geotechnical nature of thick layers of soils developed on the rocks of the lower zone of the southern slopes of Mount Bambouto (West Cameroon), a couple of observations were made. The mechanical behavior of soils as construction materials is linked to the nature of the parent rock and its environment of formation. Four different types of rock have been noted: trachybasalt, orthogneiss, anatexite, and biotite-hornblende granitoid. These rocks in a hot and humid mountain climate, exposed to the monsoon wind, have weathered to give soils with exploitable characteristics in compressed earth bricks (CEB) and pavement layers. This article proposes a method of choosing a soil for pavement layers and for the production of fired earth bricks / earth bricks treated or not with hydraulic binders, based on the nature of the bedrock and the climatic environment. Several formulation models have been defined. The performance, fairness, accuracy and adequacy of these models with real values were made by metric evaluation. So, it is:•Preliminary method for quickly and easily formulating masonry units in clay soil.•Preliminary method for quickly and easily formulating pavement layers in clay soil.•Simple and reliable method for choosing clay soils as construction materials from elementary geological information.

Preliminary deep-sea data analysis collected at Gloria seamount, Azores-Biscay Rise

The present study provides the first results of the exploratory research campaign to Gloria seamount (summit at 45.03°N, 15.54°W), a newly identified seamount in the NE Atlantic. New multibeam bathymetry and an 8 h remote operated vehicle footage and photography data were compiled and analyzed to give the first insights on the geological nature and benthic megafauna assemblages of Gloria seamount. Footage evidenced three distinct seafloor coverage areas, ranging from unconsolidated fine sediment with ripple marks, to increasingly coarser-grain sediment with large blocks, to outcrops with steep slopes along successive ridges, locally exhibiting volcanic structures. The deep-sea benthic assemblages differed with depth (2700−2450 m) and seafloor substrate type. In sediment habitats, pink holothurians (Elpidiidae) and brittle stars (Ophiuroidea) were recorded, whereas in hard substrates, sponges (Hexactinellida and Demospongiae) and stalked crinoids (Crinoidea) were mixed with distinct coral specimens, such as bamboo corals (Isidiidae) and Coralliidae (Scleralcyonacea). The integration of these data contribute to the geo-habitats knowledge of an unexplored seamount.

Relationship between fluorescence and IR parameters of oil inclusions and crude oils in the Dongpu Depression (Bohai Bay Basin, China)

The Dongpu Depression is an important petroliferous basin in China with abundance of hydrocarbons. The fluorescence characteristics of inclusion oils and their relationship with the present-day produced crude oils have never been systematically studied in the basin scale. This knowledge can further clarify ambiguities in petroleum system modeling and support exploration efforts in the area. To this end, core samples and crude oils were collected from the Shahejie Formation (Paleogene) in the Dongpu Depression to perform fluorescence and infrared spectroscopy from the source rock and the reservoir. Results show that the fluorescence characteristics of oil inclusions in the source rocks are consistent with oil inclusions in the reservoirs in the northern part of the depression, showing blue, green, yellow and orange fluorescence colors; whereas orange fluorescence is absent in the southern part in inclusions. Moreover, lack of a robust relationship between λmax and QF-535 suggests crude oils have gone through secondary alterations towards becoming heavy oil. Herein, comparison between the IR (CH2/CH3) and fluorescence parameters (λmax and QF-535) illustrates that CH2/CH3, although is suitable for organic matter thermal maturity assessment, cannot be directly applied to the expelled oils. Moreover, the occurrence of orange fluorescing oils in the horsts can be accounted for a higher hydrocarbon potential in these areas. Additionally, establishing a clear relationship between fluorescence and IR parameters failed in certain strata or structural unit, proving a complex tectonic setting of the depression. Overall, this study reveals the geologic nature of the Dongpu Depression is very complicated, which means additional analytical studies to resolve the oil-source correlation problem, in particular, would be necessary.

Physico-chemical quality of tap water in an urban environment: The case of the Massengo district, arrondissement n°9 Djiri, Brazzaville

The drinking water supply in the Massengo Soprogi district in Brazzaville's Djiri 9 arrondissement is provided by the Djiri river, whose mineralization dictates that of the water in the distribution network. Tap water in this district was analyzed for various parameters in order to understand the acquisition of mineralization. The physico-chemical analysis of these water samples showed that the water has very little mineralization, and is not very hard due to the geological nature of the Djiri riverbed (sandy soil). The pH values in the wet and dry seasons give the water a weakly acidic nature and, taking into account the concentration of bicarbonate ions, a low level of complete alkalinity. The geochemical processes responsible for this mineralization are mainly: water-rock interaction and ion exchange, and silicate dissolution. The geochemical methods used were the Gibbs diagram and the calculation of a few characteristic ionic ratios. Tap water has a strong aggressive and corrosive tendency, as revealed by Langelier's saturation index and Ryznar's stability index.

Possibilities of on-board gravimetric and hydromagnetic survey in solving engineering-geological problems on the shelf

This article shows the possibilities of using on-board gravimetry and hydromagnetometry in combination with high-resolution seismic surveys in the framework of site surveys on the Arctic shelf. Geotechnical surveys were carried out in the southern part of the Kara Sea shelf on a study area of 25 km2 in order to identify potentially hazardous areas for setting up a floating drilling rig. The studies were carried out using a regular network of observations, consisting of 51 line and 26 secant profiles. The length of each profile is 5 km. Gravimetric research were carried out with the Chekan-AM marine on-board gravimeter in conjunction with magnetometric research using SeaSPY 2 towed marine magnetometers. The depth of research when performing engineering and geological surveys using the presented set of methods is the first 100 meters, up to 1 km. In this case, objects and phenomena of both technogenic and geological nature can represent a potential hazard. As the experience of carrying out this type of work in the south of the Arctic shelf shows, paleoincisions and paleovalleys are common hazards of the geological nature of the region under study. These structures are traditionally filled with weakly consolidated, often gas-saturated, sediments with inclusions of coarse-grained material. Paleoincisions are clearly manifested in the high-frequency component of the magnetic field, and the local component of the anomalous magnetic field was calculated to reveal them. As a result of a complex interpretation of gravity field anomalies and magnetic survey data, a curved linear zone was localized, crossing the entire study area. The identified anomalous zone is confined to the boundaries of the paleoincision, which was originally discovered according to seismoacoustic studies. Based on the results of gravity surveys, an area of negative anomalies was identified in the eastern part of the study area. According to the materials of seismoacoustic in this zone, paleocuts of a complex spatial and deep configuration are traced. It is noteworthy that these structures are not manifested in a magnetic field. Based on the obtained values of the gravitational field and seismoacoustic data, a seismic-density section of meridional strike was constructed across the entire area. As a result of 2D density modeling, the densities for the undercut paleoincision were selected and two deconsolidations were found at a depth of 200 meters. One of the model “artifacts” does not appear according to seismoacoustic studies and hydromagnetometry. The detected areas of decompaction can be caused by the gas saturation of the sedimentary strata and must be taken into account when setting up a floating drilling platform. The interpretation of the anomalous gravitational field in the specified complex of geophysical methods with a priori geological information makes it possible to predict the density structure of the studied rock mass and gives recommendations for further research.

Geochemical proveniencing of the tuff used to build the Temple of Jupiter Optimus Maximus and other Archaic monuments (Rome, Italy)

This work presents the results of a geological-geochemical and archaeological study, aimed at determining the origin of blocks of Tufo del Palatino (a pyroclastic flow deposit erupted 534 ka from the Colli Albani volcanic district) used for the construction of the foundations of the Temple of Jupiter and of other important monuments of Archaic Rome (6th-early 5th c. BCE). Through the reconstruction of the underground trend and outcrop areas of Tufo del Palatino, extraction sites mentioned by historical sources and recent literature were recognized and sampled, in order to compare their geochemical signature with that of the cut blocks used by Roman builders. For this purpose, 32 archaeological samples were taken from monuments and analyzed together with 14 geological outcrop samples. By determining the ratios of particular trace elements (Zr/Y, Nb/Y, Zr/TiO2, Nb/TiO2, Th/Ta) it is possible to establish the great compositional homogeneity of all the archaeological samples analyzed and their compatibility only with outcrop samples taken from the Capitoline Hill. The evidence, both of a geological and archaeological nature, of quarry interventions on the hill in Roman times is analyzed and discussed.

Tres representaciones de Arte y Geología en el reinado de Carlos III: el Vesubio, la mina de Gualgayoc y la Gruta de Posillipo

During the reign of Charles III, the search for information about the different places in his kingdom was constant. The compilation of images culminated, on many occasions, in the commission of artistic objects that were not only limited to the decoration of rooms, but also had the function of transmitting information to their observers. This occurred within the spirit of the Enlightenment, so this information was, in many cases, not easily available the observers. Sometimes the artists in charge of their representation would not have first-hand access to these natural phenomena or landscapes, so they would have to make use of images made by others in order to carry out their commissions. This is the case of the paintings Vista de la erupción del Vesubio by A. Carnicero, Quadro de Historia Civil y Geográfica del Reyno del Perú by J.I. Lequanda and L. Thiebaut and La gruta de Posillipo en Nápoles by the Real Laboratorio de Piedras Duras del Buen Retiro. The three works analyzed in this work, and belonging to Madrid collections, show the interest that geological nature aroused in various artists of the time.

Oceanic Core Complex or not? When bathymetric structures challenge seafloor spreading models

We use regional magnetic and local multibeam bathymetric data to investigate the geological nature of a prominent high located off-axis near the junction between the Mohns and the Knipovich ridges, in the Norwegian-Greenland Sea. Given the location of this hill, near the bend marking the junction between these two ultraslow spreading centers and the bathymetric asymmetry on both sides of the ridge, an Oceanic Core Complex, corresponding to the outcropping part of an underlying detachment, was proposed as a possible interpretation. Nevertheless, the magnetization distribution over this hill is compatible with a basaltic environment and magnetic gradients are also identical to those existing in basaltic contexts, pointing towards a similar geology. Finally, a combined plate and magnetic reconstruction reveals that this hill has a conjugate structure and that regional magnetic anomalies are symmetric. These observations rule out the Oceanic Core Complex hypothesis, as detachment surfaces are often associated with a marked spreading asymmetry. We therefore propose that this protruding bathymetric feature should rather be seen as a basaltic hill and the depth asymmetry likely results from seafloor subsidence triggered by the massive accumulation of sediments from the Bear Island Fan, on the eastern flank of the ridge axis.

Reducing uncertainty on land subsidence modeling prediction by a sequential data-integration approach. Application to the Arlua off-shore reservoir in Italy

In recent years, the awareness about the critical importance of correctly dealing with uncertainty in numerical models is spreading over an increasing number of application fields, including geomechanics for energy resources. Sources of uncertainty are related for instance to the mathematical constitutive law that describes the deep rock behavior, the geomechanical parameters and the geological nature of the investigated field. Data assimilation techniques take advantage of the increasing availability of in-situ measurements in order to account for and reduce uncertainties in modeling outcomes. Recently, a comprehensive workflow for a stochastic analysis of land subsidence has been proposed. It combines a geomechanical model with successive steps of model diagnostic and data assimilation techniques, like χ2-test, Red Flag and Ensemble Smoother. Successive steps require increasing computational effort, but provide more accurate outcomes. The application of the workflow is repeated in time when new measurements become available so that the model is dynamically updated and the uncertainties are reduced. The objective of this study is to apply and validate the workflow on the Arlua reservoir. The outcome is the development and experimentation of a comprehensive geomechanical model that automatically integrates real measurements and progressively reduces the prediction uncertainties by a continuous training in time. The application confirms the effectiveness of the proposed integrated approach and proves its robustness and quality in a complex off-shore reservoir in Italy.

Neotectonic Structure of the Northern Framing of the Ubsunur Depression and Its Relation to Active Faults (Republic of Tuva, Russia)

New data on Oligocene-Quaternary sediments, recent (Neogene-Quaternary) structure and active faults of the northern side of the Ubsunur Basin at its boundary with the Tannu-Ola Ridge uplift, based on structural interpretation of remote sensing materials and field work, including trending of active faults, are presented. In the north of the Ubsunur Basin, two parageneses of faults with different geological nature, structural and relief-forming significance were identified. The first paragenesis is represented by the North-Ubsunursky hidden thrust and associated deformations that developed during Neogene‒Quaternary and which form the boundary of the depression and the mountain uplift. The second paragenesis includes the South Tannuol and Erzin-Agordag faults, which cut structures of the first paragenesis and which are active in the Late Pleistocene and Holocene. Periods of intensive development of parageneses replace each other in time.

Assessment of heavy metals and health implications in borehole water of Shao in Moro LGA, Kwara State

Problems of kidney, liver, hypertension and cancer diseases are common this day in some parts of Nigeria among adults which could be due to prolong drinking of water containing high concentrations of heavy metals such as Arsenic, Barium, Cadmium, Chromium, Copper, Lead, and Manganese. There is a need for creating awareness in the country about the health implications of prolong drinking of water with high concentrations of heavy metals which could cause some severe diseases to man. This study was conducted to determine the concentrations of some selected heavy metals in the borehole water of Shao in Moro Local Government Area, Kwara State, Nigeria. Water samples were collected in March, 2020 from 6 borehole locations at Shao and physic-chemical properties were analyzed using standard methods. The samples were collected in March during dry season to get the actual contribution of the geological nature of the area for the heavy metals. In March, there is little or no underground water pollution from agricultural wastes, pesticides, industrial wastes and percolation of contaminated runoff. The concentrations of Cadmium, Chromium, Copper, Lead, Manganese and Zinc in the samples were 0.003-0.016 (Standard Organisation of Nigeria – SON limit: 0.003), 0.012-0.012 (SON: 0.050), 0.005-0.030 (SON: 1.000), 0.058-0.058 (SON: 0.010), 0.002-0.024 (SON: 0.200), 0.013-0.098 mg/L (SON: 3.000mg/L), respectively. Concentrations of Arsenic and Mercury were not detected in all the 6 boreholes. The concentrations of Cadmium which is toxic to kidney were above the permissible limits of SON in 5 boreholes and Lead that could cause cancer and mental disorder among children were above the permissible limits of SON in one borehole. Borehole water with high concentration of heavy metals should be treated before consumption to prevent some deadly diseases that could affect man.