The study deals with the Geophysical investigation of Iwo and Ilesha, Osun State, using aeromagnetic data. Qualitative as well as quantitative interpretation of the aeromagnetic data were carried out to obtain more information about the thickness of sedimentary basins. Two methods were used in the interpretation; there are Euler deconvolution method and source parameter imaging (SPI). Oasis Montaj software was employed in the analysis, the Magnetic intensity ranges from a minimum value of -22.7 nT to a maximum value of 110.4 nT, this indicate that the area is characterised with low and high magnetic signature and could be as a result of difference in magnetic susceptibility, depth and the nature of the magnetic anomalous bodies present. The depth for magnetic source ranges from 187.6 to 1005.5 m using parameter imaging (SPI).Using Euler deconvolution method, the depth estimation for structural index (SI = 0.5, 1.0, 1.5) ranges from 300 m to 25481m, 262.9m to 1826.2m and 391.0m to 3243.6m respectively. The results obtained indicate shallow depths to magnetic anomalies which may not be suitable for hydrocarbon accumulation.

The usefulness of groundwater vulnerability mapping cannot be overemphasized in planning, policy formulation and decision-making for groundwater management and protection. The present study employed geographic information system based overlay and index methods (DRASTIC, DRASTIC-LU, GOD and AVI models) in assessing and mapping groundwater vulnerability zones in Ile Oluji area of Ondo State, Southwestern Nigeria. The models’ parameters were prepared using hydrogeological (well/borehole) data, geophysical data, and satellite imageries. The weightage of different parameters was done using analytical hierarchy process. The DRASTIC map classified the area into the low vulnerability (30 % of the area), moderate (4%), high-vulnerability zone (60 %), and very high vulnerability zone (6 %). The DRASTIC-LU distinguished the area into high – very high groundwater vulnerability zone (90 %), while low – moderately low area has 10 % aerial extent. The GOD and AVI models, categorized the vulnerable areas into quite low (<0.03) to low (0.03 – 0.3); and high (0.98 – 1.85) to extremely high (<0.98) vulnerability zones respectively. As a result, the DRASTIC, DRASTIC-LU, and AVI models all showed predominate high vulnerability zone, which was also confirmed by the nitrate map. The index values in the DRASTIC and DRASTIC-LU models revealed significant overlap. Therefore, in the research region, slope, hydraulic conductivity, net recharge, soil medium, and depth to water level are the factors that have the greatest influence on groundwater quality. Due to the significant number of highly vulnerable places, the aquifers must be protected immediately.

The Banket Series, which is a paleoplacer deposit, is the third formation in the stratigraphy of Tarkwaian Supergroup. This project seeks to study petrographically; the lithologies in the banket series to confirm the rocks identity as already known or state otherwise. Two different photomicrographs of each of the rock samples, coupled by their petrographic descriptions were obtained from the laboratory. The main areas of our arguments were based in Bowen’s reaction series, metamorphic facies of the rocks, the earth structure and thermodynamic phase diagrams. The sampled rocks can be confirmed with the help of thin sections and mineral facies to be conglomerate, dolerite and quartzite. The minerals in the banket series range in temperature between 200°C and 800°C. The abundance of silica (SiO2) in the rocks conglomerate, dolerite and quartzite are of crustal origin, whereas pyroxene and olivine originate from the upper mantle. The common stable minerals in the studied rocks, namely, amphibole, chlorite and plagioclase are less likely to change compared to the other minerals in the rocks. The three (3) different metamorphic facies of the rocks conglomerate, dolerite and quartzite are respectively greenschist, epidote-amphibolite and amphibolite facies.

This paper seeks to assess the potential of Alkali-Silica Reaction on some granitic rocks in Kumasi in Ghana. Alkali-Silica reactions occur over time between alkaline cement paste and silica contained in rock aggregates as a result of the swelling due to the reaction of certain constituents in the rock aggregates with alkali hydroxides. Alkali-Silica reactions become potentially harmful when they cause significant expansion. Aggregates used for this research were sought from three different quarries, namely, Consar Stone Quarry in Barekese, Nnagot Quarry in Kona and Modern Granite Quarry in Buoho. To achieve the objectives of this project, two test methods were employed such as Accelerated Mortar Bar test (ASTM C1260) and Petrographic analysis. Presence of strained quartz is an indicator for the occurrence of Alkali-Silica Reaction. Samples from Kona contained quite an appreciable amount of strained quartz and exhibited an expansion above the ASTM C 1260 specification, implying that it is potentially reactive and thus not useful for construction works, whilst samples from Barekese, and Buoho were innocuous and may be used for construction works. Supplementary cementing materials such as pozzolans (which are readily available) can be added to concrete mixtures with aggregates from Kona to reduce the harsh effects of ASR.

In this appraisal, heavy metal concentrations in soils from Zamfara State were enumerated approximately a decade after the lead poisoning saga using indexes of pollution. The area is enhancement with valuable ores and minerals including gold making mining the most lucrative business in the area. The soils were moderate to slightly basic with a pH range from 6.49 ± 0.12 to 7.96 ± 0.15 (water) and 6.15 ± 0.10 to 7.80 ± 0.17 (KCl). Contamination / pollution (C/P) values reported for cadmium, lead, zinc and copper was 42.66, 0.59, 0.85 and 3.04 in the respective order (severe contamination to excessive pollution). The contamination factor (CF) was greater than the highest factor of 6, indicating very high contamination. The calculated values for geochemical accumulation (Igeo) and ecological risk factor (ERf) for Cd, Pb, Zn and Cu was (19.26, 0.27, 0.38, 1.37) and (1280, 2.95, 0.85, 15.2) respectively while the potential ecological risk index (ERi) was 1299, indicating that the soils were perturbed (polluted). Considering the deleterious effects heavy metals could cause and the resultant health implications, there is need to further remediate the polluted areas so as to avert harm to organisms and humans would consume crops grown in such environment.

One of the most common problem faced by geotechnical engineers is slope stability assessment. The predictions of slope stability in soil or rock masses is very important for the designing of reservoir dams, roads, tunnels, excavations, open pit mines, and other engineering structures. It is the importance of slope stability problem that has reasoned alternate methods for evaluating the safety of a slope. This study reviews the existing methods used for slope stability analysis. These methods are divided into five different groups which are; (a) Limit equilibrium method, (b) Numerical simulation method, (c) Artificial neural network method, (d) Limit analysis method, and (e) Vector sum method.

Soil erosion is one of the principal causes of soil degradation in Sandakan, Sabah, Malaysia. The natural phenomenon of erosion is now accelerated by human activities that alter the natural mechanisms. This acceleration is caused by destruction of plant cover, the growing of wrong cultivations, unsuitable farming techniques etc., all of which may be prevented with correct management and land planning. Soil erosion has been identified as one of the important environmental issues and therefore, detail assessment on prediction of soil loss and its impacts has been carried out using the application of the Modified Soil Loss Equation (MUSLE) and Geographical Information System (GIS). ARC-INFO was used for the storage of the data layer on each factor controlling soil erosion. Identification of potential high-risk erosion areas was made using a thematic data layering approach to analyze risk areas. The quantitative soil loss (t ha-1 yr-1) ranges estimates by MUSLE model by a spatial information analisis approach (GIS) were computed: (a) Very High risk (>150 tons/ha/year); (b) High risk (100-150 tons/ha/year); (c) Moderate risk (50-100 tons/ha/year); (d) Low risk (10-50 tons/ha/year); and (e) Very low risk (<10 tons/ha/year). About 46.33% of the area was classified as very low, 43.50% as low, 5.23% as moderate, 4.49% as high and 0% as very high. Soil erosion hazard has been identified and found to be significant in areas with slope above 36.96o. All findings showed that integration of GIS can be used for spatial analysis in a large scale. Production of A total value maps can be applied to particular development planning areas especially for housing and agriculture developments.

A practical application for landslide susceptibility analysis (LSA) based on two dimensional deterministic slope stability (infinite slope model) (DESSISM) was used to calculate factor of safety (FOS) and failure probabilities for the area of Kota Kinabalu, Sabah. LSA is defined as quantitative or qualitative assessment of the classification, volume (or area) and spatial distribution of landslides which exist or potentially may occur in an area. In this paper, LSA value can be expressed by a FOS, which is the ratio between the forces that make the slope fail and those that prevent the slope from failing. An geotechnical engineering properties data base has been developed on the basis of a series of parameter maps such as effective cohesion (C’), unit weight of soil ,)(depth of failure surface (Z), height of ground water table (Zw), Zw/Z dimensionless (m), unit weight of water ,)w(slope surface inclination (β) and effective angle of shearing resistance (). Taking into consideration the cause of the landslide, identified as groundwater change, the maximum groundwater level recorded corresponding to the actual situation of the most recent landslide is considered in this study. The highest probability value of the various scenarios was selected for each pixel and final LSA map were constructed. It has been found from this study that β and Zw parameters have the higher influence on landslide instability. The result validation between the examined LSA map and result of landslide distribution map (LDM) were evaluated. This DESSISM had higher prediction accuracy. The prediction accuracy is 84%. The resulting LSA maps can be used by local administration or developers to locate areas prone to landslide area, determine the land use suitability area and to organize more detailed analysis in the identified “hot spot” areas.

This landslide study was conducted in Kampung Mesilou, Kundasang. Desk study, field study and data analysis used were based on recorded slides occurred in 2008, July 2013, November 2013 and June 2015. These episodic landslides have significant impact on road, concrete bridge, vegetable gardens and killed a farmer. Factors that control the slides are natural and anthropogenic activities. The natural factors include geological characteristics, weathering, excessive precipitation and natural river phenomena. Human activity is represented by unguided cutting slope for development purposes. The geological factor consists of unconsolidated Pinosuk Gravel rock unit, topography and occurrence of active northeast-southwest fault zone crossing this area. High weathering rate has weakening the underlying rock unit as well as heavy precipitation. Intermittently high energy during storm of the main river channel of Mesilou River has been increasing the rate of erosion at slope base since few decades. Natural slope was steepened during road construction and become less stable. Slope stability analysis has confirmed the slope is unstable with FOS < 1, especially during rainy session.

This study was conducted on two selected slopes in Kota Kinabalu area of Sabah. The area is underlain by Crocker Formation which consisting of interbedded sandstone and shale layers. The objectives of this study are to determine the Geological Strength Index (GSI) rating, rock mass properties and slope stability for the selected slopes. Engineering geological mapping and discontinuity survey were conducted to obtain quantitative description of discontinuities as well as rock sampling based on grain sizes. GSI rating and disturbance factor was obtained from discontinuity survey and field observation on the slope face, respectively. Residual GSI rating was determined using empirical method. Laboratory study was done to determine the Uniaxial Compressive Strength via point load test and unit weight by dry density test along with the intact rock constant. Rock mass properties such as cohesion, friction angle, tensile strength, Young’s modulus and residual strength were determined by applying GSI system into the Hoek-Brown criterion. Kinematic analysis and finite element analysis were conducted to identify localised mode of failure and the safety factor of the selected slopes. Prescriptive measures were used to determine the rock cut slope designs. GSI rating for both slopes were obtained with both slopes can be considered as stable according to kinematic analysis and finite element analysis. Prescriptive measures for slope protection are needed to prevent water pressure build up and future failure.