Implications of the Engineering Geological Properties of Soils in the Implementation of the Greater Jos Master Plan, North Central Nigeria

2021 ◽  
Vol 6 (5) ◽  
pp. 118-128
Author(s):  
Hannatu N. Wazoh ◽  
Stephen J. Mallo
Keyword(s):  
Water Table ◽  
Geological Mapping ◽  
Engineering Properties ◽  
Master Plan ◽  
Rapid Urbanization ◽  
Additional Information ◽  
Rock Types ◽  
Subsurface Soil ◽  
Static Water ◽  
Water Level Measurements

A study of the engineering properties of the subsurface soil in the Greater Jos Master Plan development area has been carried out to address the paucity of engineering data in the area. The study became necessary because the rapid urbanization has led to limited construction land with more ground prone to instability due to reworking by mining and related activities. The study area is located within Latitudes 09º 48' 20'' to 09º 53'20''N and Longitudes 08º 53' 54'' to 08º 57 '00'' E and extending over 54km2 on Naraguta Sheet 168NE. Surface geological mapping was carried out to confirm the existing geology. Geotechnical properties of soils were determined by analysis of soil samples for 38 locations. While 94 static water level measurements provided additional information on groundwater conditions. The area is underlain by the Jos-Bukuru Complex rocks predominantly biotite granites differentiated on the basis of mode of formation, mineralogy and texture. Soils derived from weathering of the rocks revealed gradual decomposition from gravel, sand, and silt-sized particles to lateritic clays. The soils are considered to have low to medium plasticity/compressibility, expansiveness, and swelling potential across all rock types. The static water table depicts fluctuation in the water table varying between 2.9 and 3.9m. These findings are expected to serve as guide in the choice of design and construction and as a baseline subsurface soil compendium for planning and urban development in the Greater Jos Master plan and for further studies.

scholarly journals Influence of Water Table Fluctuation on Natural Source Zone Depletion in Hydrocarbon Contaminated Subsurface Environments

2020 ◽  
Author(s):  
Reem Ismail ◽  
Saeid Shafieiyoun ◽  
Riyadh Al Raoush ◽  
Fereidoun Rezanezhad
Keyword(s):  
Water Table ◽  
Contaminated Soil ◽  
Soil Surface ◽  
Source Zone ◽  
Water Table Fluctuation ◽  
Mass Removal ◽  
Water Table Fluctuations ◽  
Water Conditions ◽  
Static Water ◽  
Influence Of Water

Most of the prediction theories regarding dissolution of organic contaminants in the subsurface systems have been proposed based on the static water conditions; and the influence of water fluctuations on mass removal requires further investigations. In this study, it was intended to investigate the effects of water table fluctuations on biogeochemical properties of the contaminated soil at the smear zone between the vadose zone and the groundwater table. An automated 60 cm soil column system was developed and connected to a hydrostatic equilibrium reservoir to impose the water regime by using a multi-channel pump. Four homogenized hydrocarbon contaminated soil columns were constructed and two of them were fully saturated and remained under static water conditions while another two columns were operated under water table fluctuations between the soil surface and 40 cm below it. The experiments were run for 150 days and relevant geochemical indicators as well as dissolved phase concentrations were analyzed at 30 and 50 cm below the soil surface in all columns. The results indicated significant difference in terms of biodegradation effectiveness between the smear zones exposed to static and water table fluctuation conditions. This presentation will provide an overview of the experimental approach, mass removal efficiency, and key findings.

Structural and microtectonic analyses of Barpak of Gorkha district, west-central Nepal

2020 ◽  
Vol 60 ◽  
pp. 163-179
Author(s):  
Sameer Poudel ◽  
Lok Mani Oli ◽  
Lalu P. Paudel
Keyword(s):  
Dynamic Recrystallization ◽  
Geological Mapping ◽  
Dolomitic Marble ◽  
Rock Types ◽  
Central Nepal ◽  
Phase Deformation ◽  
West Central ◽  
Shear Sense ◽  
Shear Sense Indicators ◽  
Cylindrical Folds

Geological mapping was carried out in the Barpak-Bhachchek area of the Daraudi River valley, Gorkha district, West-Central Nepal for structural analysis. The area comprises rocks of the Higher Himalayan Crystalline and the Lesser Himalayan Sequence.  Pelitic and psammitic schist, quartzite, calc-quartzite, dolomitic marble, graphitic schist, gneiss are the main rock types within the Lesser Himalayan Sequence,  whereas banded gneiss and quartzite form a significant portion of the Higher Himalayan Crystalline in the study area. The area is affected by poly-phase deformation. Lesser Himalayan Sequence has suffered five deformational phases (DL1-DL2, D3-D5) whereas the Higher Himalayan Crystalline has suffered four deformational events (DH1, D3-D5). The Lesser Himalayan Sequence lying to the northern limb of the Gorkha-Kuncha Anticlinorium is contort into doubly plunging to dome-and-basin-like en echelon type of non-cylindrical folds as Baluwa Dome and Pokharatar Basin (DL2 and D4). The direction of shearing as indicated by shear sense indicators (C' Shear band and Mica fish) is top-to-south coinciding with regional sense of shear related to the MCT propagation. The dynamic recrystallization direction, obtained from rock dominant with phyllosilicate minerals is top-to-south and coincides with mineral lineation and indicate the mineral lineation is contemporary with dynamic recrystallization during the MCT propagation.

scholarly journals Multi-geophysical data integration using cluster analysis: Assisting geological mapping in Trøndelag, Mid-Norway

2020 ◽  
Author(s):  
Ying Wang ◽  
Anna K Ksienzyk ◽  
Ming Liu ◽  
Marco Brönner
Keyword(s):  
Cluster Analysis ◽  
Data Integration ◽  
Geological Mapping ◽  
Geophysical Data ◽  
Supervised Machine Learning ◽  
Spatial Density ◽  
Depth Information ◽  
Rock Types ◽  
Gravity Measurements ◽  
Single Attribute

Summary Modern geophysical data acquisition technology makes it possible to measure multiple geophysical properties with high spatial density over large areas with great efficiency. Instead of presenting these co-located multi-geophysical datasets in separate maps, we take advantage of cluster analysis and its pattern exploration power to generate a cluster map with objectively integrated information. Each cluster in the resulting cluster map is characterised by multi-geophysical properties and can be associated with certain geological attributes or rock types based on existing geological maps, field data and rock sample analysis. Such a cluster map is usually high in resolution and proven to be more helpful than single-attribute maps in terms of assisting geological mapping and interpretation. In this paper, we present the workflow and technical details of applying cluster analysis to multi-geophysical data of a study area in the Trøndelag region in Mid-Norway. We address the importance of carefully designed pre-processing procedures regarding the input datasets to ensure an unbiased data integration using cluster analysis. Random Forest as a supervised machine learning method for classification/regression is strategically employed post-clustering for quality evaluation of the results. The multi-geophysical data used for this study include airborne magnetic, frequency electromagnetic and radiometric measurements, together with ground gravity measurements. Due to the nature of these input data, the resulting cluster map carries multi-depth information. When associated with available geological information, the cluster map can help interpret not only bedrock outcrops, but also rocks underneath the sediment cover.

Do the relationships between testate amoebae and fungi reflect the variability of past water table fluctuations in the ombrotrophic peatlands of Central Europe?

The Holocene ◽  
2020 ◽  
Vol 30 (8) ◽  
pp. 1186-1195
Author(s):  
Piotr Kołaczek ◽  
Monika Karpińska-Kołaczek ◽  
Mariusz Gałka ◽  
Grażyna Miotk-Szpiganowicz ◽  
Milena Obremska ◽  
...  
Keyword(s):  
Central Europe ◽  
Water Table ◽  
Pollen Analysis ◽  
Calluna Vulgaris ◽  
Testate Amoebae ◽  
Cold Climate ◽  
Testate Amoeba ◽  
Additional Information ◽  
Sphagnum Peat ◽  
Climate Events

In this article, we examined the indicative value of a relationship between two non-pollen palynomorphs (NPPs), fungal HdV-10, related to the presence of Calluna vulgaris, and HdV-31A, which is testate amoeba – Archerella flavum. Both are frequently present on slides designated for pollen analysis, prepared from Sphagnum peat. We analysed three profiles from three extensive ombrotrophic peatlands in northern Poland, in which the content of testate amoebae (TA) was examined and TA-inferred depth to the water table (DWT) was reconstructed. The new analysis of palynological samples regarding NPPs revealed that strong increases in HdV-10 content were mostly simultaneous to HdV-31A declines. However, the relations between both types were not statistically significant. The rapid increases in HdV-10, despite the fact that this type of conidiospores is related to drier habitats on peatlands, were tentatively interpreted as an indicator of rapid rises in the water table level which, in consequence, might have stimulated the production of these spores by fungi. In addition, a negative correlation between HdV-31A and Arcella discoides and positive one, but weaker, in case of HdV-10 (attributed by some authors to species Trichocladium opacum (Corda) S Hughes) and A. discoides show a link between mutual fluctuations of both NPPs and hydrological instabilities on peatland. The Bagno Kusowo bog, the westernmost peatland subjected to the study, displayed an intriguing agreement between the presence of peat sections with strong increases in HdV-10 and cold climate events affecting Europe. Our study reveals that counting even a limited number of NPP types during the standard pollen analysis of Sphagnum peat may support the interpretation of results, especially, in cases when the investigation lacks testate amoeba analysis. When the reconstruction of TA-inferred DWT is provided, it may introduce additional information about the patterns of hydrological dynamics.

Computerized geological mapping in the Grenville Province, Quebec

1970 ◽  
Vol 7 (6) ◽  
pp. 1357-1373 ◽  
Author(s):  
H. R. Wynne-Edwards ◽  
A. Nandi ◽  
M. M. Kehlenbeck ◽  
A. F. Laurin ◽  
K. N. M. Sharma ◽  
...  
Keyword(s):  
Processing System ◽  
Structural Data ◽  
Data Bank ◽  
Geological Mapping ◽  
Grenville Province ◽  
Geological Interpretation ◽  
Rock Types ◽  
Potential Map ◽  
Computer Based ◽  
Project Data

Since 1965, the Quebec Department of Natural Resources has conducted reconnaissance mapping in the Grenville Province, completing to date over 70 000 square miles (181 000 km2). In 1968 a computer-based data processing system was designed at Queen's University, and applied to this Grenville Project. Data are recorded in the field on input documents designed to recover a complete description of the structure and lithology of an outcrop in a standard and reproducible form. From these records a data bank, now with descriptions of over 5000 outcrops, has been constructed for the field seasons of 1968 and 1969. Lthological sorting programs based on the textural and mineralogical qualities used to define rock types have been written to provide listings of some 40 potential map-units. Outcrop maps identifying lithologies have been drawn on a computer-driven drum plotter to provide the geologist with a basic document from which to make geological interpretation. Structural data have been extracted and plotted in equal-area projections, and also plotted on maps directly by machine, using standard structural symbols for layering, foliation, and lineation. The system has upgraded the standard of data collection in the field, and provides a rapid and versatile means of handling data and of interpreting the geology. The data bank, when made publicly available, will enable users of government geological maps and reports to reinterpret the area in their own manner, or freely to add any proprietary data in the preparation of revisions.

scholarly journals Hyperspectral analysis of lithologies in the Arctic in areas with abundant lichen cover

2018 ◽  
pp. 51-55
Author(s):  
Sara Salehi
Keyword(s):  
Remote Sensing ◽  
Chemical Composition ◽  
Mineral Exploration ◽  
Spectral Characteristics ◽  
Image Data ◽  
Geological Mapping ◽  
The Arctic ◽  
Electromagnetic Spectrum ◽  
Rock Types ◽  
The Impact

Lithological mapping using remote sensing depends, in part, on the identification of rock types by their spectral characteristics. Chemical and physical properties of minerals and rocks determine their diagnostic spectral features throughout the electromagnetic spectrum. Shifts in the position and changes in the shape and depth of these features can be explained by variations in chemical composition of minerals. Detection of such variations is vital for discriminating minerals with similar chemical composition. Compared with multispectral image data, airborne or spaceborne hyperspectral imagery offers higher spectral resolution, which makes it possible to estimate the mineral composition of the rocks under study without direct contact. Arctic environments provide challenging ground for geological mapping and mineral exploration. Inaccessibility commonly complicates ground surveys, and the presence of ice, vegetation and rock-encrusting lichens hinders remote sensing surveys. This study addresses the following objectives: 1. Modelling the impact of lichen on the spectra of the rock substrate; 2. Identification of a robust lichen index for the deconvolution of lichen and rock mixtures and 3. Multiscale hyperspectral analysis of lithologies in areas with abundant lichens.

scholarly journals MAGNETOMETRIC AND GAMMA-RAY SPECTOMETRY EXPRESSION OF SOUTHWESTERN SÂO FRANCISCO BASIN, SERRA SELADA QUADRANGLE (1:100.000), MINAS GERAIS STATE

2012 ◽  
Vol 30 (4) ◽  
pp. 445 ◽  
Author(s):  
Humberto Luis Siqueira Reis ◽  
Maria Sílvia Carvalho Barbosa ◽  
Fernando Flecha de Alckmim ◽  
Antonio Carlos Pedrosa Soares
Keyword(s):  
Gamma Ray ◽  
Low Frequency ◽  
Geological Mapping ◽  
Weathering Processes ◽  
Rock Types ◽  
High K ◽  
Minas Gerais State ◽  
Basement High ◽  
Tectonic Features ◽  
Low K

Localizada na porção sudoeste da Bacia do São Francisco, a área abrangida pela Folha Serra Selada (1:100.000) contém rochas sedimentares deformadas do Grupo Bambuí (Neoproterozoico), localmente recobertas, em pronunciada discordância, pelos sedimentos e depósitos vulcanoclásticos/epiclásticos cretáceos dos grupos Areado e Mata da Corda, respectivamente. Os dados aerogeofísicos mostram dois domínios magnetométricos principais. Um deles é caracterizado por anomaliasde baixa frequência (ABF), aparentemente relacionadas a estruturas do embasamento pré-cambriano local. O outro é marcado por anomalias de alta frequência (AAF),representando os depósitos vulconoclásticos/epiclásticos do Grupo Mata da Corda. O Grupo Bambuí exibe teores de K e Th intermediários a altos (1 a 3% e 10 a 16ppm, respectivamente), enquanto os teores de U giram em torno de 2,5 ppm. Esse dados mostram algumas variações, geralmente influenciadas pela distribuição dos diferentes litotipos, feições estruturais e ocorrência de emanações de hidrocarbonetos. Os sedimentos do Grupo Areado, por sua vez, mostram baixos conteúdos deK, Th e U (<1%, <10 ppm e <2 ppm, respectivamente). As rochas do Grupo Mata da Corda e coberturas associadas têm teores muito baixos de K (subtraços) e altas concentrações de Th e U (>20 ppm e >3 ppm, respectivamente). Estes valores parecem sofrer grande influência dos processos de intemperismo. As análises realizadas confirmam a grande aplicabilidade dos levantamentos aerogeofísicos no mapeamento geológico e constituem excelentes ferramentas no entendimento do cenário tectônico e dos depósitos de hidrocarbonetos da região sudoeste da Bacia do Sâo Francisco. ABSTRACT: Located in the southwestern portion of São Francisco Basin, the region covered by the Serra Selada quadrangle (1:100.000) contains deformed rocks ofthe Neoproterozoic Bambuí Group, unconformably overlain by Cretaceous sedimentary and volcaniclastic rocks of the Areado and Mata da Corda groups, respectively. The aerogeophysical data shows two main magnetometric domains. A low frequency anomalies domain is apparently related to deep structures of Precambrian basement. High frequency anomalies represent the volcaniclastic/epiclastic deposits of Mata da Corda Group. The Bambuí Group exhibits intermediate-to-high K and Th contents (1 to 3% and 10 to 16 ppm, respectively), while U-levels are around 2.5 ppm. Significant changes in these values are caused by the distribution of rock types, tectonic features and hydrocarbon exudations. Areado Group sediments show low K (<1 %), low Th (<10 ppm) and low U (<2 ppm). Mata da Corda Group volcanics and associated covers exhibit very low K (sub-traces), and high Th and U concentrations (>20 and 3 ppm, respectively). These values seem to be strikingly influenced by weathering processes. The performed analyses confirm the applicability of aerogeophysical data in geological mapping, and represents an important tool for the studyof both the tectonic scenario and hydrocarbon accumulations in south western São Francisco Basin.Keywords: magnetometry, gamaespectrometry, Serra Selada Quadrangle, São Francisco Basin.

scholarly journals Reconnaissance geochemical and geophysical exploration for gold at Iri gold field, north central Nigeria

2020 ◽  
Vol 18 (2) ◽  
pp. 19-31
Author(s):  
Ahmed Sidi Aliyu ◽  
Nuhu Musa Waziri ◽  
Hadiza Liman Mohammad ◽  
Mohammed Abubakar Mohammed ◽  
Apeh Aromeh Gideon
Keyword(s):  
Gold Mineralization ◽  
Structural Features ◽  
Parent Material ◽  
Geological Mapping ◽  
Magnetic Data ◽  
Geochemical Data ◽  
Aeromagnetic Data ◽  
Geophysical Exploration ◽  
Rock Types ◽  
Soils And Sediments

Reconnaissance geochemical and geophysical exploration for gold was carried out at IRI Gold field. Geological mapping was conducted and rocks, soils and sediments samples were collected. The outcome revealed rocks of the basement complex of Nigeria made up of mainly, Migmatite Gneiss, Older Granite and the Schist. The major lithology in the area is silicified sheared rocks and large quartz vein. Isolated occurrence of undifferentiated schist was found as parent material on which quartzite intruded possibly during a major geological activity. Shattering of the rocks left boulders and rubbles of quartzite all around two major ridges within the study area. The rocks have shown weak geochemical anomaly except in two locations were positive anomalies were observed and identified as target for further exploration. Gold veins are prominent in the area suggesting potential gold mineralization. Interpretation of the aeromagnetic data give the orientations of the structural features, the major structural trend in the area is NE-SW. The lineaments extracted from the magnetic data range in length from 46.43m to about 1251.66m. Most of the lineaments extracted from the area are subsurface within the quartz-mica and migmatites while some of them have surface expressions even though not clearly defined. These magnetic lineaments could be the contacts between two rock types of contrasting magnetic   susceptibility   or   edges   of   structures   that   could   be faults or intrusive bodies. Interpreted satellite data show several subsurface structures which could be hosts to gold mineralization in the area. Results of the geochemical analysis of rocks, soils and sediments were super imposed on the interpreted aeromagnetic data and similar geochemical and geophysical signatures were established.   Index Terms: Gold mineralization, aeromagnetic data, geochemical data, schist belt, Nigeria

Brief introduction to the geology of the Ilímaussaq alkaline complex, South Greenland, and its exploration history

2001 ◽  
pp. 7-23 ◽  
Author(s):  
Henning Sørensen
Keyword(s):  
Major Part ◽  
Nepheline Syenite ◽  
Geological Mapping ◽  
Type Locality ◽  
Alkaline Complex ◽  
Precise Description ◽  
Rock Types ◽  
Rare Elements ◽  
Exposed Part ◽  
Radioactive Minerals

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Sørensen, H. (2001). Brief introduction to the geology of the Ilímaussaq alkaline complex, South Greenland, and its exploration history. Geology of Greenland Survey Bulletin, 190, 7-23. https://doi.org/10.34194/ggub.v190.5170 _______________ The Ilímaussaq alkaline complex, the type locality of agpaitic nepheline syenites, is made up of three intrusive phases, (1) augite syenite, (2) alkali acid rocks and (3) agpaitic nepheline syenites which occupy the major part of the complex. The agpaitic phase comprises a roof series, a floor series and an intermediate sequence of rocks. The roof series crystallised from the roof downwards beginning with non-agpaitic pulaskite and ending with distinctly agpaitic naujaite. The exposed part of the floor series is made up of the layered agpaitic nepheline syenite kakortokite. The intermediate sequence consists of several types of distinctly agpaitic lujavrites which are accompanied by occurrences of uranium and other rare elements. The complex was first visited by K.L. Giesecke in 1806 and 1809. The first detailed mapping of the complex was carried out by N.V. Ussing in 1900 and 1908. He presented a precise description of the major rock types and an illuminating discussion of the petrology of the complex in his 1912 memoir. In the period 1912–1955 there was very limited activity in the complex. Exploration for radioactive minerals in Ilímaussaq was initiated in 1955 and in subsequent years followed by geological mapping carried out by the Geological Survey of Greenland. This led to a series of detailed studies of the occurrences of not only U, but also Be, Nb, REE and Zr, and to mineralogical, geochemical and petrological studies as well as commercial evaluation and drilling.

ASSESSMENT AND REMEDIATION OF A LIGHT NON-AQUEOUS PHASE LIQUID HYDROCARBON PLUME IN FRACTURED BEDROCK

2019 ◽  
Vol 5 (1) ◽  
pp. 1-24
Author(s):  
Ian Mitchell
Keyword(s):  
Water Table ◽  
Liquid Hydrocarbon ◽  
Structural Features ◽  
Geological Mapping ◽  
Canadian Forces ◽  
Fracture Density ◽  
Fractured Bedrock ◽  
Access Road ◽  
Preferential Pathways ◽  
Hydrocarbon Product

INTRODUCTION During the extension of an access road on the Canadian Forces Base (CFB) Esquimalt in Colwood, British Columbia, a black, viscous, liquid hydrocarbon product was observed oozing from newly exposed bedrock fractures in the roadside. Road excavation was subsequently halted to undertake assessment and remediation of the hydrocarbon product. The exposed bedrock was dammed with sawdust, a geomembrane barrier was installed and the area was backfilled until an appropriate course of action could be determined. The site location is shown in Figure 1. The property boundary and key site features are shown in Figure 2; the hydrocarbon seep is shown in Figure 3. Bunker C oil is a heavy-end (high molecular weight) hydrocarbon product that has a specific gravity slightly less than water and is therefore a light non-aqueous phase liquid (LNAPL). The source of the LNAPL was inferred to originate from a decommissioned fuel depot located approximately 100 m distance uphill from the road, where 40,000 barrels of Bunker C fuel oil were historically stored in one of three, large above-ground storage tanks (ASTs). A Bunker C oil spill reportedly took place at the tank farm more than two decades prior; however, the spill volume was unknown and initial investigations found no evidence of contamination between the roadside LNAPL occurrence and the former AST. Furthermore, there was also anecdotal evidence that an historic asphalt manufacturing facility may have operated in the vicinity of the access road. A hydrocarbon product similar to Bunker C is used in the manufacture of asphalt. The source and extent of the LNAPL and the potential migration pathways to the roadside location were therefore unknown. When an LNAPL spill occurs in the subsurface, the LNAPL can migrate downward under gravity through the soil pore space in the unsaturated zone. When LNAPL encounters the ground water table (the top of the saturated zone), it tends to spread out laterally because it is less dense than water and will migrate primarily in the direction of the water table gradient (water table slope). However, when LNAPL encounters bedrock, the direction of LNAPL migration can become much more complicated depending on the degree and orientation of bedrock fractures that control its movement. When fracture density is sufficiently high and the fractures are interconnected, contamination is able to migrate down-gradient through the bedrock in the same manner as through unconsolidated materials. However, when dominant structural features are prevalent that favour specific orientations, preferential pathways are created that can result in the cross-gradient migration of LNAPL. This paper presents a case study for the assessment and remediation of LNAPL in bedrock at the Canadian Forces Base (CFB) Esquimalt (the site). Geological mapping of bedrock structural features has long been used by the mining industry to identify key structures associated with economic zones of mineralization and to predict the location and extent of mineralized targets. In a similar regard, to effectively remediate LNAPL within fractured bedrock requires the identification and characterization of any structural features that might be controlling the preferential migration of LNAPL within the subsurface to other areas of the site. A significant amount of surface outcrop is present at the site and this was recognized as a cost-effective opportunity to complete a geological assessment of the bedrock. A geological mapping program was subsequently undertaken to assess bedrock outcrops for fracture density, fracture aperture, the orientation of primary fracture sets and lithologic contacts. The area was also inspected for larger scale structural features such as faults, deformation and erosional features that might influence contaminant migration. Fracture sets and lithologic contacts were mapped by outcrop location, and fractures with visible LNAPL were mapped separately from those without LNAPL. The geological data collected was used to construct stereographic projections of structural planes on a stereonet. Poles to structural planes were plotted and colour-coded by area and by presence/absence of LNAPL. The plots were then analyzed individually, and as a composite plot, to identify the dominant preferential pathways controlling LNAPL migration at the site. By superimposing these features on areas where LNAPL was observed, LNAPL delineation targets were effectively identified and the plume was subsequently delineated with confidence and remediated.

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