Earth Science

This paper analysed the possibility of expansion of Nekede Mechanic-Village gully located in Imo State Nigeria using Geotechnical tests method. The gully site is located on longitude 7o 2’ 6”E and latitude 5o 27’ 46”N. The analysis of the Geotechnical tests showed that Site Areas 3 and 4 are structurally week and susceptible to erosion due to their poor Shear Strength and Bulk Density values – in addition to being Non-Plastic. In contrast, site areas 1 and 2 are relatively stable. Sites 3 and 4 are located close to residential areas thus demanding desperate attention from government agencies before the expanding gully wreaks havoc.

In the present study, investigation of the chemical quality of water at the Qareh sou catchment has been carried out to evaluate the suitability of water for irrigation purpose. Water quality of the area has been studied based on physico- chemical analysis of six hydrometer stations during 2010. Various parameters, such as pH, EC, chloride, sulfate, bicarbonate, sodium, potassium, calcium and magnesium have been determined to evaluate this purpose. Irrigation water quality on the basis of Doneen’s permeability index, residual sodium carbonate, sodium adsorption ratio, Magnesium adsorption ratio, Kelley’s ratio, Corrosivity Ratio, potential soil salinity and Chadha’s diagram have been computed. Results showed that the water was suitable for irrigation purpose. According to Chadha’s diagram, the type of water is determined as Ca–Mg–HCO3. Also, according to the Wilcox diagram water classified as ‘excellent’ and ‘good’, except for the Siah ab and Naharkhoran stations, but Corrosivity Ratio suggests that the Qareh sou water is not safe for Water Transmission. In shastkola and pol ordgogah stations, the value of MAR is harmfully over 50%.

Radiation and radioactive isotopes constitute a natural part of our environment. High concentrations of these radioactive isotopes in the environment can be a threat to our health. The largest fraction of the natural radiation we receive comes from the radioactive gas radon, which disintegrates by emitting alpha particles. Although it cannot be detected by human senses, radon and its radioactive by-products are a health concern because they can cause lung cancer when inhaled over many years. Radon is present everywhere in the rock, soil, water and air because of the ubiquitous nature of its parent radioactive element uranium in geological terrain. In this paper, we highlight the need for measurement of radon in the environment, and the possible health hazards due to radon gas, especially from building materials and water in Ghana. We present preliminary results from our recent work and suggest remedial measures to avoid high intake of radon. In the preliminary results, using the BEIR III model to calculate the distribution of lung cancer cases per year in Dome in 2009 between the different age groups from radon exposure of 2.03 WLM per year gave a total of 5 cases per year.

The Eastern Dahomey Basin is a rift basin located in the Southwestern part of Nigeria with formations spanning from the Cretaceous to Tertiary ages which are well defined in their lithology types ranging from sand, silt, carbonates, and shale. Shale is now considered as a reservoir rock in the unconventional petroleum system unlike its previous characterisation as only a source rock and/or seal in the conventional petroleum play. The hydrocarbon field operators in the Dahomey basin have reported higher percentage of gas production up to 20% LPG and 52% gas and also identified the syn-rift to contain light oil and condensate-rich gas. The increasing demand of natural gas as a cleaner energy compared to other fossil fuels and the several commercialization strategies of the Federal Government of Nigeria has necessitated the exploration possibility of more gas, even unconventional gas. This paper reviewed the geological and geochemical properties of the Dahomey basin from previous authors and selected some producing plays in the USA as possible analogues for its shale gas potential.

This work entails a palynostratigraphy and palynoclimatic study of Ochigbo – 1 well, offshore Niger Delta. A total of Sixty-two (62) ditch samples were composited at intervals at an average of 100ft. The well covered total depth of 3,405-10,640ft. These samples were subjected to standard procedure for palynological study. Recovered palynomorph were rich, diverse and well preserved. The recovered palynomorphs were used for identifying four main palynological zones. These are: Crassoretitriletes vanraadshooveni/P700 Zone characterized by the quantitative base occurrence of Crassoretitriletes vanraadshooveni and co-occurrence of Belskipollis elegans, Crassoretitriletes vanraadshooveni, Echiperiporites estalae, and Verrutricolporites rotundiporus; dated Middle Miocene; Magnastriatites howardii/P600 Zone characterized by quantitative base occurrence of Peregrinipollis nigericus and co-occurrence of Praedapollis flexibilis, Magnastriatites howardii and Monoporites annulatus; dated Early Miocene – Late Oligocene; Retibrevitricolporite obodoensis/protudens/P500 Zone characterized by the co-occurrence of Arecipitesexili muratus, Retibrevitricolporite obodoensis/protudens, Verrucatosporite susmensis and Gemmamonoporite ssp dated Late – Early Oligocene and Racemonocolpite shians/P400 Zone characterized by the base occurrence of Racemonocolpite shians. The palaeoclimatic investigation showed that the sediments were deposited predominantly under wet climate in a mangrove setting and the palaeoenvironment ranges from brackish to deep marine environments.

With the consideration of sustainable development, three major objectives of watershed management in Iran are to lessen disaster, to secure local residents and their properties, and to conserve natural resources. Many single-objective management projects have applied to Iran’s watersheds for the last several decades to achieve those objectives, including soil conservation projects. However, conventional planning methods are not capable to handle the complexity and conflicts of mutli-objective watershed management projects. In this study, an integrated model combining Geographic Information Systems (GIS), Remote Sensing (RS), soil erosion model, and multiple criteria decision making (MCDM) is developed and applied for the planning of reservoir watershed management in Joneqan watershed, Iran. Performance of individual objective for each alternative is first estimated with the aid of GIS, RS, and soil erosion model. After the procedures of MCDM, a compromising solution is suggested based on the identified preferences on project objectives and their performances of all objectives. Besides, a list of alternatives with their priorities can provide further information on the trade off relationships among our objectives.

Common field practice for electrical surveying relies on directly placing an electrical current into the ground (direct current electrical resistivity surveying) and measuring the response (the electrical potential drop) to that current over a set distance. Resistivity analysis was conducted at a site earmarked for a radioactive waste disposal facility known as the Borehole Disposal Concept (BDC) at the Ghana Atomic Energy Commission’s site located at Kwabenya, in the Greater Accra Region of Ghana. Both resistivity profiling also known as electric trenching and vertical electrical sounding also known as electric drilling were employed in this study. The results from both techniques were processed and discussed. Medium to very low apparent resistivity were measured at certain stations/points on the survey lines which suggest the presence of geological structures/contacts such as faults and fractures at or around these stations. With the aid of the electrical sounding data the site was characterized as a four layer formation with the bedrock lying at depth of 17 m and beyond.

Detailed structural interpretation was carried out on the three fields within Block-X with the aim of better understanding the structural evolution, trapping styles and the influence of the fault system on the facies distribution within the Block. Well correlation was carried out on six wells to map potential reservoir intervals, which in turn were tied with seismic for horizon and structural interpretation. Structures interpreted include listric growth faults, roll-overs, synthetic and antithetic faults. The faults showed a dominant NW-SE trend, and the variance attribute also validated the interpreted fault trend. Impact of a mobile clay substratum was more noticeable around ‘FLO’ and ‘A’ Fields around the Upper Eocene to Lower Oligocene strata of the Agbada Formation. Four-way closures dominate ‘OGEY’ Field, the traps on ‘FLO’ Field are fault assisted while ‘A’ Field at best have some good leads which given some more control on the seismic acreage and possibility of good prospects. The facies model showed minor shale content localised at the western part of the Block with good reservoirs and and some silty sand making up the remaining Block. The fault system of the Block was not observed to have any significant effect on the facies and property distribution. The fluid contact model revealed communication across the fields and that the reservoir is not compartmentalised. This integrated approach in determining the hydrocarbon potential of Block – X, Northern Depobelt of Niger Delta reduces the effect of under estimation and over estimation of hydrocarbon –in – place volume, thus assisting in well planning and input into running Petroleum economics.

The impacts of waste-stream from aluminium plant on the Inyishi River was investigated by analyzing the physical and chemical contents of the river using Atomic Absorption Spectrophotometer (AAS) and digital meters. The results shows that the pH of the river varies from 5.80 to 6.10 while the total dissolved solids (TDS) varies from 13.50 to 20.50mg/l. The electrical conductivity varies from 22.50 to 34.17µS/cm while total alkalinity range from 9.80 to 12.50mg/l. The concentrations of Ca2+ varies from 2.80 to 3.10mg/l while Mg2+ range from 2.60 to 2.86mg/l. Na+ concentrations varies from 5.85 to 7.10mg/l while K+ varies from 9.00 to 11.00mg/l. The concentrations of HCO3- varies from 20.50 to 21.90mg/l while that of SO42- range from 3.29 to 4.90mg/l. Al3+ concentrations varies from 0.22 to 0.29mg/l while total iron concentrations range from 0.50 to 0.64mg/l. F- concentrations varies from 0.30 to 0.80mg/l while that of BOD range from 3.60 to 5.40mg/l. Dissolved oxygen (DO) concentrations varies from 6.50 to 7.10mg/l while the total coli form range from 50 to 80 cfu/100ml. The results also show that the Sodium Adsorption Ratio (SAR) of the river varies from 0.58 to 0.74 while the Pollution Index (PI) varies from 0.68 to 0.72. Except for the pH, total coli form and Al3+ , the concentrations of other measured parameters conformed to World Health Organization (WHO) 2006 and Nigerian Water (2008) safe standards f0r drinking water. The acidic nature of the river, high concentrations of Al3+ and significant concentrations of total iron, F- and BOD are attributed to the waste-stream which is discharged into it from the Aluminium Extrusion plants in the study area. The impacts of the waste-stream on the river and its watershed include damage of coconut (cocos nucifera) trees and raffia palms (raphia ruffia) resulting in the decline of coconut, rope, local gin and palm wine production as well as decline in the cultivation of certain varieties of vegetables such as fluted pumpkin (telfairia occidentalis), water leaf (talonum tiangulare), garden eggs (salomum macrocarpum) and green (amarantus hybridias) near the river; it has also resulted in the decline in fishing activities and use of the water for drinking purposes. About 1,000 persons who live at a distance of 0.5km away from the river were observed to be at very high risk to the impacts of the waste-stream on the river. Pre-disposal treatment of the waste-stream and well programmed monitoring of the physical and bio-chemical characteristics of the Inyishi River is the best approach to maintain is resource status and usefulness.

The study evaluated the effect of anthropogenic activities on the physico-chemical properties of soils of Awka South, LGA, Anambra state, Southeastern Nigeria. Triplicate soil samples were collected from different soil depths (0-15, 15-30 and 30-45 cm) in four land use types: sand mining, play ground, arable land and forest land of Agu Awka, Amawbia, Okpuno and Ifite respectively. Physico-chemical properties of the soils were analyzed using standard methods. Analysis of variance and correlation analysis were performed using Genstat Statistical Package Version 18. Results showed that soil properties were significantly (P<0.05) influenced by the different anthropogenic activities and were not uniformly distributed down the depths. Soils were dominated by loamy sand and were moderately compacted with low moisture content. The soils were generally acidic (4.47-.5.83) irrespective of depth and landuse.Organic carbon (0.263-0667 %) and total nitrogen (0.028-0.069 %) were low and were seriously reduced by human activities. Available phosphorus (6.12-8.91 ppm) was seriously increased in sand mining compared to other land use types, moreover, sand mining activities had impacts on the levels of Ca (5.32-1.99 cmolkg-1) and Na (0.020-0.32 cmolkg-1). Total exchangeable acidity was reduced in all the land use types apart from playground where there was slight increase (1.57-1.70 cmolkg-1). Total exchangeable bases and ECEC followed decreasing pattern of forest > arable land > sand mining > playground. Soil pH had significantly positive association with OC, TN, Ca, Mg, TEB, EEC, %BS, TP and MC. To improve the fertility status of these soils especially arable land, the use of organic and/or inorganic fertilizer is required. The regulation of mining activities in the study area was also recommended to protect the soil from further degradation.