Browsing by Author "Iyakwari, Shekwoyandu"

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    Discerning mineral association in the near infrared region for ore sorting
    (Department of Geology and Minning, Nasarawa State University Keffi, 2017-03-08) Iyakwari, Shekwoyandu; Glass, Hyike J.; Obrike, Stephen E.
    The preconcentration or early rejection of gangue minerals in mineral processing operations is investigated using sorting, based on interpretation of near infrared sensor data collected from ore particles. The success of sorting depends on the distribution of minerals between particles, the arrangement or association of minerals within particles and the ability of near infrared to distinguish relevant minerals. This paper considers minerals associa- tion, using common alteration minerals found in a hydrothermally-formed copper ore, with sensitivity in the near infrared region. The selected NIR-active minerals were arranged along the view of NIR line scanner to stim- ulate adjacent natural minerals association. It was found that spectral dominance may depend on minerals near infrared sensitivity and or the position of a mineral along the NIR scanner line of view. Analysis also revealed that only free occurring waste mineral spectra can be targeted for discrimination as tailings. Where spectra appeared mixed, such spectra are best considered products.
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    Impact of heavy metal concentration around lead-zinc mining sites in Nasarawa Eggon, part of middle Benue Trough, Nigeria
    (Department of Geology and Minning, Nasarawa State University Keffi, 2018-10-09) Yusuf, Abdulwahid; Iyakwari, Shekwoyandu; Stephenson, Randell A.
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    Kwoi 2016 Multiple Tremors: An Emerging Geotourism Phenomenon
    (Department of Geology and Minning, Nasarawa State University Keffi, 2017-01-01) Goki, N.G.; Baba, Adama Oleka; Iyakwari, Shekwoyandu; Tanko, I.Y.; Kana, A.A.; Umbugadu, A.A.; Usman, Halima Osu
    For a stretch of three days, the residents of Kwoi, Central Nigeria were held hostage by what is now accepted as an earth tremor of magnitudes ranging between 2.9 and 3.1. In its initial stages, various versions of interpretations were given including religious and traditional myths. These triggered national and international attention making the area to be temporarily a tourist’s attraction of some sorts with different groups visiting and reporting different versions. The aim of this paper is to report first hand the occurrence of systematic cracks on rocks and buildings as well as the safety aspects associated with this tremor. The study confirms that this is a purely geoscientific phenomena triggered by deep seated tectonic movements manifested on the surface through short distance travel of the accompanying vibrations which lead to collapse and breakage of buildings. It is unpredictably episodic but relatively safe for tourists as an intra-cratonic tremor.
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    Lineament analysis and interpretation for assessement of groundwater potential ofWamba and environs, Nassarawa state. Northcentral Nigeria
    (Department of Geology and Minning, Nasarawa State University Keffi, 2011-02-02) Anuda, G.K.; Obrike, Stephen E.; Iyakwari, Shekwoyandu; Onuba, L.N.
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    Near infrared sensors for minerals identification and discrimination in the extractive industries
    (Department of Geology and Minning, Nasarawa State University Keffi, 2014-01-06) Iyakwari, Shekwoyandu; Usman, Halima Osu; Umbugadu, A.A.
    This paper considers the early identification and discrimination of copper bearing minerals from their associated gangue minerals. The proposed mineral identification and discrimination is based on individual mineral spectral signature(s) in the near infrared region. Ten copper ore samples, sampled from Akiri mine, Akiri, Awe Local Government Area of Nasarawa State Nigeria were analysed. Individual samples were subjected to mineralogical analysis using X-ray diffraction equipment and elemental analysis using hand-held X-ray florescence equipment. Prior to the mineralogical and elemental analysis, samples were scanned with a near infrared line scanner. Results of the X-ray diffraction, X-ray florescence and near infrared were compared. The comparison indicated that in addition to the minerals identified by the XRD, other NIR-active minerals with concentration below the XRD detection limit (5%) were also detected by the near infrared line scanner. Hence, the near infrared line scanner had a better detection limit. Furthermore, eight out of the ten samples analysed showed a good correlation where near infrared and elemental data were compared
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    NITRATE CONCENTRATION AND GROUNDWATER VENERABILITY IN TYPICAL SHALLOW BASEMENT AQUIFERS AROUND KEFFI AREA, NORTH-CENTRAL NIGERIA
    (Department of Geology and Minning, Nasarawa State University Keffi, 2011-11-06) Obrike, Stephen E.; Anudu, G.K.; Iyakwari, Shekwoyandu; Nghargbu, K.; Osadebe, C.C.
    Keffi 414 environs is characterized لا near surface outcrops o f underlying basement rocks and s h a lli overburden thickness.The study assessed tire potential ofnitrate-nitrogen (NOj-N) contamination o f surface and groundwater within the study area. Thirty-two groundwater samples and four stream samples were collected from different locations across the study area and analysed for their NO٢N concentration. Groundwater sampling were restricted to well-covered shallow hand-dug wells SHW}, medium depth hand pumps (MHP) and motorised boreholes (DMBH). In all the groundwater samplesanalysed,12.5°/oofthemexhibitedN03-Ncontentshigherthan O h g L 1 and 60% o f the samples collectedfrom the agricultural fields contained N o ٢N higher than 0 .05mgL؛ in contrast to 20% of samples from residential areas. Results also revealed an inverse relationship between the NOj-N concentrations and the depth o f the sampling aquifers (SHW>MHP>DMBH). All of the analysed samples contained NO3-N load 1656 than thefixed threshold limit by WHO (2006١ for drinkingpurposes of below lOmgi;1, thus, rendering the waters safe for drinking purposes.
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    NITRATE CONTAMINATION IN GROUNDWATER AROUND KEFFI TOWN, NORTHCENTRAL NIGERIA
    (Department of Geology and Minning, Nasarawa State University Keffi, 2011-08-08) Obrike, Stephen E.; Anuda, G.K.; Iyakwari, Shekwoyandu; Osadebe, C.C.
    Ten (10) vertical electrical soundings (VES) were carried out in the study area, the field data obtained were then interpreted using partial curve matching and a 1-D inversion algorithm. Resistivity results indicate the presence of top soil (<300 ohm- m), weathered basement (100 to 150 ohm-m) and fractured basement (<3000 ohm-m). The thickness of the topsoil is generally less than 2m while the weathered basement varies from 5m to 30m. Fifteen (15) groundwater samples were collected from different locations across the Keffi area and analysed for their NO3-N concentration. Groundwater sampling were restricted to well-covered shallow hand-dug wells (SHW), medium depth hand pumps (MHP) and motorised boreholes (DMBH). In all the groundwater samples analysed, 10.5% of them exhibited NO3-N contents higher than 0.03mgL-1 and 65% of the samples collected from the agricultural fields contained NO3- N higher than 0.03mgL-1 in contrast to 15% of samples from residential areas. Results also revealed an inverse relationship between the NO3-N concentrations and the depth of the sampling aquifers (SHW>MHP>DMBH). Most of the analysed samples contained NO3-N load less than the fixed threshold limit by WHO (2006) for drinking purposes of below 10mgL-1, thus, rendering the waters safe for drinking purposes.
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    PRELIMINARY APPRAISAL OF CHEMICAL AND GEOTECHNICAL PROPERTIES OF CLAY DEPOSITS IN DOMA AREA, MIDDLE BENUE TROUGH, NIGERIA
    (Department of Geology and Minning, Nasarawa State University Keffi, 2011-06-06) Essien, B.I.; Obrike, Stephen E.; Anuda, G.K.; Iyakwari, Shekwoyandu
    A appraisal of the chemical and geotechnical properties o f the Dorna sedimentarp claps was conducted and consequently assessed for their possible industrial potential.The chemical analpsis o f samples repealed the predominance of ) 2.04-9.01%(,1:0٤)0,94- 3.94%/,7٧40000.83-1.10%/,04000.05-0,91%( ,* 2 0 )0.21-1.82%( 4/147420) 0.08-0.18%(. The characteristic physicalparameters o f the clap specimens included linear shrinkage (3.6-15.6%), plastic limit (15 20%), liquid limit (25 41%) andplasticitp index (5 20% ). 1716 chemical and geotechnical properties o f the Dorna claps indicated that they are potentially suitable for the production o f ceramics, pottery and refractorp bricks
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    Preliminary geological evidence for multiple tremors in Kwoi, Central Nigeria
    (Department of Geology and Minning, Nasarawa State University Keffi, 2020-01-09) Goki, Nathaniel; Onwuka, Solomon Anayo; Baba, Adama Oleka; Iyakwari, Shekwoyandu; Tanko, Ishak Yau; Abubakar, Aisha Kana; Umbugadu, A.A.; Usman, Halima Osu
    Preliminary field assessment of the geological evidence for the September 2016 multiple tremors was felt as far as 10 km in Nok and Chori villages in the north and northwest of Kwoi respectively. This involved systematic studies of the crack pattern and intensity on buildings, rocks and hanging walls of slopes around the area with the highest shock. The structural mapping was complemented by composite images of SPOT 5, supplementary subsurface investigations utilized aeromagnetic data, seismic data, and Digital Terrain Model (DTM) for the area. Results show that the major evidence that proved a possible link to the area of highest impact is the tremor triggered displacement of a 4 by 3 m diameter rock boulder situated about a kilometre from the Kwoi town, some 3 km from the nearest epicentre that fell through a cumulative distance of 25 m, splitting the fresh granite boulder into two and creating a high impact scar on its path. Seismic vibrations that shook the residents of Kwoi and environs (with epicentres located along a NE-SW linear traverse and remotely coinciding with buried fractures) appear to have been generated and propagated laterally from the rocks along a northwest-southeast profile. Despite the non- homogenous strengths of the impacted buildings, the near-consistency of the E-W striking walls being the most fractured gives a remote connection with the major 345° to 015° fracture patterns on the granitic plutons that shields Kwoi town to the north. Additionally, the intensity of the fractures and collapse in the buildings increased south-westwards from the perceived area of highest impact. A possible tectonic origin related to stress build up in the rocks of the area for the tremors can be insinuated thereby foreclosing the theory of a non-tectonic origin being considered in some quarters including the recent Mpape Abuja tremor of 2018. All these epicentres plot along an extrapolated trend that coincides with the Chain Fracture Zone of the North Atlantic.
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    Preliminary structural study of Landsat Imagery overWamba and Environs, Nasarawa state, Northcentral Nigeria
    (Department of Geology and Minning, Nasarawa State University Keffi, 2012-01-03) Anuda, G.K.; Obrike, Stephen E.; Iyakwari, Shekwoyandu; Ikpokonte, A.E.
    Wamba and environs is underlain by the migmatities, gneisses. Older Granites, Younger Granites, Awgu Shale and Lafia Formation. LANDSAT 5-TM imagery over the area has been analysed and interpreted in order to determine the lineament trends, drainage network and lineament density across the area. Rose (azimuth-frequency) diagram plots of the structures (lineaments) from both the imagery and field measurements show NE-SW, NNE-SSW, E-W, NNW-SSE andN-S directions with the dominant trends intheNE-SW andNNE- ssw directions. Two prominent faults (Fl, F2) were identified on the imagery. The superposition of the lineament map and drainage map depicts that the dendritic drainage pattern of the area is lithologically and structurally controlled. The lineament map, lineament density contour map, lineament density image map and lineament density surface map show that the lineament density is high around Monkwar, Zamatak, Ninkade, Mugu, Gwanzu and Garko underlain by migmatites, gneisses and Older Granites.
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    The risk o f groundw ater contam ination from land-use activities in shallow basem ent terrains, a case o f K effi and environs, N orth Central Nigeria.
    (Department of Geology and Minning, Nasarawa State University Keffi, 2017-03-13) Obrike, Stephen E.; Anuda, G.K.; Iyakwari, Shekwoyandu; Abubakar, Aisha Kana; Umbugadu, A.
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    Safety Practices in Surface Mining in North Central Nigeria
    (Department of Geology and Minning, Nasarawa State University Keffi, 2010-03-04) Baba, Adama Oleka; Iyakwari, Shekwoyandu; Obrike, Stephen E.; Anuda, G.K.