Global Journal of Geological Sciences https://www.ajol.info/index.php/gjgs <p><em>Global Journal of Geological Sciences</em> is aimed at promoting research in all areas of Geological Sciences including geochemistry, geophysics, engineering geology, hydrogeology, petrology, mineralogy, geochronology, tectonics, mining, structural geology, marine geology, space science etc. </p><p>Visit the Global Journal Series website here: <a title="http://www.globaljournalseries.com/" href="http://www.globaljournalseries.com/" target="_blank">http://www.globaljournalseries.com/</a></p><p> </p> en-US <span>©</span> 2018. This work is licensed under the creative commons Attribution 4.0 International license. bachudo@yahoo.com (Prof . Barth N. Ekwueme) info@globaljournalseries.com (Prof . Barth N. Ekwueme) Thu, 25 Jun 2020 00:00:00 +0000 OJS 3.1.2.4 http://blogs.law.harvard.edu/tech/rss 60 Geochemistry and paleoenvironment of the phosphorites from the Ameki Formation, Niger delta, Nigeria https://www.ajol.info/index.php/gjgs/article/view/197007 <p>The phosphorites of the Ameki Formation occur as nodules, pellets as well as primary phosphatic shales and siltstones. Geochemical analysis of the phosphate samples was carried out to determine its chemical composition as well as its depositional environment. The methodology applied include XRF, INAA, XRD and thin section petrography using Polarizing Microscope. The XRF result identified CaO- P<sub>2</sub>O<sub>5</sub>- F as the major mineral group, SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, Fe<sub>2</sub>O<sub>3</sub>, MgO and TiO<sub>2</sub>, which show minor occurrences and Cr, U, Pb, V, Cu, Zn, Se and Cd that occur in trace amounts. The nodules and pellets are of medium to high grade (25- 34wt% P<sub>2</sub>O<sub>5</sub>) whereas the primary phosphatic shales and siltstones are of low to medium grade (4.5– 22wt% P<sub>2</sub>O<sub>5</sub>). The phosphorites comprise mostly of francolites. The mean index of refraction estimated by Becke-line method using Standard Polarizing Microscope gave 1.634 and1.636.XRD analysis yielded an average values of 9.243 (± 0.002) A° and 6.715 (± 0.002) A° for a and c crystallographic axes respectively with an axial ratio (c/a) of 0.726for unit cell parameter, suggestive of low degree of carbonate substitution. An increase in P<sub>2</sub>O<sub>5 </sub>content is found to be accompanied by increase in CaO, CO<sub>2</sub> and F contents, but by a decrease in H<sub>2</sub>O, organic carbon, SiO<sub>2</sub> and Fe contents indicative of amorphous solid phase of calcium phosphate. The phosphorite is interpreted to form under high biologic productive, shelf setting. High nutrient availability in the ancient sea is linked to upwelling along the West African Coastline during the Eocene.</p> <p><strong>Keywords</strong>: Phosphorites; Geochemistry; Paleoenvironment; Ameki; Francolites; Nodules </p> Evangeline Njideka Onuigbo, Anthony Uwaoma Okoro, Stella ‘Nwaife’ Chibuzor Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/197007 Thu, 25 Jun 2020 00:00:00 +0000 Application of geological and electrical resistivity methods for groundwater studies at Tatiko, North Central Nigeria https://www.ajol.info/index.php/gjgs/article/view/197008 <p>The success probability of water wells constructed in crystalline rock terrains is largely dependent on the size, location and interconnectivity of the fractures present in them as well as the amount and nature of the material that may clog the fractures. Geological and geoelectrical studies were proposed and conducted at Tatiko to determine the structures in the underlying basement rocks and evaluate their groundwater potential. Geological study was used to delineate the structural control on groundwater availability while the geoelectrical study (Vertical Electrical Sounding) was used to investigate the properties of the subsurface materials and determine their potential to host sufficient quantity of groundwater.<br>Structural data were plotted on a rosset diagram and showed major structural control trending in the NW – SE direction. Quantitative interpretation of the geoelectric data indicates that the major fractures are within the weathered to competent basement indicating good hydraulic connection between the weathered and fresh basement. The fractures are deepest within the region that showed thicker weathering and are as shallow as 7 meters in other regions. Apparent resistivity of the fractures ranges between 100Ωm and 1200Ωm in most parts of the area with the highest values in the west. An integration of the result clearly showed that the NW and SW parts of the study area are the most favourable for drilling and further groundwater studies and drilling is recommended to a depth of 40m to 50m.</p> <p><strong>Keywords</strong>: Groundwater, Geoelectrical study, Fractures, Tatiko, Resistivity, Basement Complex. </p> Abdulwahid Kolawole Aweda , Ibrahim Kagara Shehu , Olusegun Omoniyi Ige , Mohammed Umar Umar, Joseph Barde David Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/197008 Thu, 25 Jun 2020 00:00:00 +0000 Paleo-environmental deduction from pebble morphometry and textural studies of sandstone deposits of Isuochi and Environs, Anambra Basin, South Eastern Nigeria https://www.ajol.info/index.php/gjgs/article/view/197009 <p>Textural analysis and pebble morphomentric were carried out on the sandstone deposits of Isuochi area in Anambra Basin, in an attempt to&nbsp; reconstruct the paleoenvironment of deposition. Field observation shows that the sandstone samples, collected from various locations were&nbsp; analyzed for sieve analysis, while two hundred fresh quartz pebbles that are greater than 2.00mm in diameter were collected for pebble&nbsp; morphomentric. Morphomentric parameters include; elongation ratio, flatness index, oblate index, and maximum projection sphericity were computed. Bivariate plots of Maximum Projection Sphericity against Oblate Prolate Index show that about 69% of the pebbles are of fluvial origin,<br>while 31% is surf, bivariate plots of Flatness Index against Maximum Projection Sphericity show that about 57% is of fluvial origin, while 43% show surf; these imply that the associated pebbles are of fluvial origin. Bivariate plots of sandstone textural parameters such as skewness against standard deviation also suggest that the sediments are more of fluvial origin while multivariate parameter shows partly shallow marine&nbsp; environment.</p> <p><strong>Keywords</strong>: Pebble Morphometry, Oblate-Prolate Index, Paleoenvironment.</p> Ejiofor C. Ezike, Henry I. Okonkwo, Emmanuel C. Iyi Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/197009 Thu, 25 Jun 2020 00:00:00 +0000 Geophysical investigation of foundation failure at Medina Estate, Lagos, Southwestern Nigeria https://www.ajol.info/index.php/gjgs/article/view/197010 <p>Integrated geophysical investigation involving Ground Penetrating Radar (GPR) and Electrical Resistivity methods were carried out at Medina Estate, Lagos southwestern Nigeria to map the subsurface lithology in order to delineate its peat stratigraphy that has been causing foundation failure in the area. Twenty-one traverses (varying from 35-880 m in length) of Ground Penetrating Radar (GPR) survey were conducted along the streets of Medina trending NE-SW and NW-SE directions using the Mala 250 MHZ bi-static shielded antenna. Thirty-six Vertical Electrical Soundings (VES) were carried out using Schlumberger electrode array at some selected points along the established traverses within the area. The GPR data were processed into radar section using Rad Explorer software. The VES data were interpreted quantitatively using the partial curve matching method and 1-D forward modeling with Win Resist Software. Available litho-logs from boreholes drilled within the area were compared with the geophysical results.&nbsp; Results of the GPR survey delineated three geologic layers which include the topsoil with high amplitude, parallel to sub parallel, horizontal reflections, with thickness varying from 1 to 2 m across the entire profiles and composed of lateritic clay; peat layer with low amplitude, parallel sinuous/wavy reflections with depth of occurrence ranging from 2.0 to 8 m and clay with low amplitude, planar, horizontal, sub-parallel reflections underlying the peat layer. Vertical Electrical Sounding results revealed the presence of three geological layers which are the topsoil, peat and clay and sandy clay with layer resistivity values ranging from 20- 225 Ωm, 5 – 90 Ωm and 36 to 366 Ωm and thickness values ranging from 0.5 – 2 m, 4.0-29.0 m and infinity respectively. Borehole information confirms the occurrence of shallow peat with depth ranging from 1.5 to 9 m and clay layer with depth ranging from 9 to 21 m beneath the area. The GPR survey results correlates with the well logs acquired in the study area. Based on the correlation of the geophysical results with the well logs, the GPR gives better information about the peat layer compared to the Electrical Resistivity<br>Method. The information obtained from this study shows that the soils at shallow depth are organic soils which are difficult foundation materials because they exhibit very high compressibility, as such making shallow foundation impossible except some form of soil improvement is carried out. The alternative approach is the adoption of deep foundations in form of piles.</p> <p><strong>Keywords:</strong> Foundation Failure, Geophysical Investigation, Ground Penetrating Radar, Vertical Electrical Sounding, Peat.</p> M.A. Oladunjoye, K.O. Adejato, A.O. Ogunkoya Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/197010 Thu, 25 Jun 2020 00:00:00 +0000 Compositional characteristics and Ta-Sn-Nb rare metal mineralization potential of Egbe Pegmatite, Southwestern Nigeria https://www.ajol.info/index.php/gjgs/article/view/201239 <p>Pan African (600 ± 150) pegmatite which intrudes gneisses, amphibolites, quartzite and schists around Egbe area were studied for their compositional features. This is with a view to characterizing and assessing their potential for rare metal Ta-Sn-Nb mineralization. Twenty seven samples comprising eleven (11) whole rock, sixteen (12) muscovite extracts and four (4) feldspar extracts samples were analyzed using the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Major oxide geochemical assessment of the whole rock pegmatite indicates that the pegmatite is siliceous (79.82% SiO<sub>2</sub>) and moderately high in Al2O3 (12.22%). The K<sub>2</sub>O, Na<sub>2</sub>O contents are averagely 2.25% and 2.87% respectively while Fe<sub>2</sub>O<sub>3</sub>, MnO, MgO are each less than 1.0%.</p> <p>Average values of trace elements in the pegmatite are Ta (52.55ppm), Sn (92.3 ppm), Rb (1083.5ppm), Nb (109.35 ppm), Cs (32.12ppm), Sr (17.84 ppm), Y (9.86 ppm), and Zr (41.27 ppm), Ba (50.47ppm), Hf (12.38ppm), Zr (41.27ppm), Ga (32.12ppm) and W(2.91PPM) and ratios of diagnostic elements are K/Rb (30.27), Rb/Sr (298.93), Zr/Hf (7.23), Rb/Cs (65.80), K/Cs (1103.11), Ta/W (41.81), Nb/Ta (55.397) Na/Rb (41.77) and Na/K (92.25) A/CAN &gt;1and Al<sub>2</sub>O<sub>3</sub>&gt;CaO+ Na<sub>2</sub>O+ K<sub>2</sub>O with enrichment of SiO<sub>2</sub>, Al<sub>2</sub>O<sub>3</sub>, Na<sub>2</sub>O, K<sub>2</sub>O and depletion of Fe<sub>2</sub>O<sub>3</sub>, MnO<sub>2</sub> and MgO suggests that Egbe pegmatite is of peraluminous bulk composition and plots of A/NK vs Al/CNK and Rb vs (Y+Nb) discriminates Egbe pegmatite in the peraluminous LCT (Li, Rb, Cs, Be, Ga, Nb &lt;,&gt; Ta, Sn, Hf, B, P, F) of syncollisional to within plate granitic family. The Ta/W vs Cs plot for the three sample media shows the relationship between increasing Ta/W ratio and elemental fractionation as indicated by Cs. The K/Rb vs Cs and K/Rb vs Rb plots for the three sample media further establishes the rare – metal nature and mineralization potential of Egbe pegmatite. Using the discriminant plots of TaVs Rb, Ta vs Cs .TaVs K/Cs, and Ta Vs (Cs+Rb) where most of the samples of the whole rock pegmatite and mineral extracts plots above the Beus line and about 30% plotting above the Gordinyenko line respectively. Overall geochemical assessment is that Egbe pegmatite is a rare metal, highly fractionated Beryl type with rare metal enrichment trend of Nb&gt;&gt;Sn&gt;&gt;Ta.</p> <p><strong>Keywords:</strong> Pegmatite, Peraluminous, Syncollisional, Within-plate, Discriminant, Fractionation, Sample media</p> J.A. Aderogbin, O.A. Okunlola Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/201239 Tue, 03 Nov 2020 00:00:00 +0000 Granulometry, heavy mineral and geochemical studies of stream sediments around Bula, Dass District, Northeast Nigeria https://www.ajol.info/index.php/gjgs/article/view/197011 <p>Active stream sediments generally consist of broken-down fragments of pre-existing rocks by the action of river (stream) flow. This makes them target materials for routine geochemical surveys and provenance analysis. Fifteen (15) stream sediment samples were collected in some parts of Bula and its environs, northeastern Nigeria, in order to determine their textural characteristics, heavy mineral and elemental composition. The sediments were subjected to granulometric, heavy mineral and elemental analyses. The result of granulometric analysis show that the stream<br>sediments are poorly to moderately well sorted, very platykurtic to leptokurtic, fine to medium grained and positively skewed. Zircon, rutile and tourmaline are the dominant heavy mineral species occurring in the sediments. The computed Zircon-Tourmaline-Rutile (ZTR) index values for the samples range from 59.18 - 83.53, indicating mineralogical maturity. The geochemical data of the stream sediment samples show that the mean contents of the trace elements [Ti (0.73 ± 0.74%), Fe (0.39±0.19%), Cr (816±639ppm), Ni (258±108ppm), Pb (48±12.37ppm) and Zn (502±126ppm)] were higher than their respective average crustal values except for Fe. Computed threshold values indicate possible mineralization containing Fe and Ti. The elements have variable spatial distribution. The study shows that the trace elements composition of the stream sediments is majorly lithogenic. Because mineralization in rocks and sediments are often characterized by considerable variation in their trace elements contents, the metal concentrations in these sediments are large enough for Ilmenite and Rutile mineralization to be suspected within the study area. </p> C. I. Adamu, E.E. Okon, D.O. Inyang Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/197011 Thu, 25 Jun 2020 00:00:00 +0000 Variations in geotechnical characteristics of some crude oil contaminated soils https://www.ajol.info/index.php/gjgs/article/view/197012 <p>Variations based on the effects of curing time and environmental exposures on the geotechnical characteristics of some crude oil contaminated soils were investigated. 2 to 10% by weight of crude oil was added to soils as a simulation of contamination. The contaminated soils were cured under room temperature (unexposed) as well as outside in the open air (exposed) for 21, 63 and 189 days. Geotechnical, geochemical and&nbsp; mineralogical analyses were carried out on the contaminated and uncontaminated soil samples. Results indicate that for the unexposed soils, the LL and PL increased as crude oil concentration (COC) increased up to 4%, above which both decrease. But the reverse was the case for PI after curing for 21 days. With increasing curing time to 63 and 189 days, LL and PL both increased with increase in COC while PI decreased. The UCS increased with increase in oil content up to 4%, but decreased as oil content increased above 4%. Furthermore, UCS decreased with increase in curing time. Across all curing periods, MDD increased upon addition of crude oil up to 4%, thereafter it decreased with increase in COC. The hydraulic conductivity decreased with increase in COC and curing time. For the exposed soils, LL, PL and PI all increased upon addition of crude oil up till 4% before decreasing as the amount of oil increased above 4% for the curing duration of 21 days. For 63 and 189 days, LL and PL decreased while PI increased. Maximum dry density (MDD) showed same variation trend in exposed soils similar to that shown by the unexposed soils. Hydraulic conductivity increased with increase in COC and curing time. Thus, crude oil is observed to be capable of altering the geotechnical properties of soils exposed to it. Furthermore, contaminated soils exposed to the open air and longer curing time were significantly modified than the unexposed variant and with reduced exposure time.</p> <p><strong>Keywords</strong>: Geotechnical variation, Contamination, Curing environment, Curing time, Exposure </p> Ibrahim Adewuyi Oyediran , Nchewi Ideba Enya Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/197012 Thu, 25 Jun 2020 00:00:00 +0000 An assessment of heavy metals concentration in water around quarries and barite mine sites in part of central Cross River State, Southeastern Nigeria https://www.ajol.info/index.php/gjgs/article/view/201241 <p>The assessment of the level of heavy metal concentrations in water sources around quarries and barite mine sites in central Cross River State, Southeastern Nigeria, was carried out to evaluate the degree of contamination due to mining and quarrying activity in the area. The investigation involved the collection of twelve water samples from ponds, streams, river and boreholes around the area. The water samples were passed through 0.45 µm filter paper and preserved with a drop of 0.1M HNO<sub>3</sub> acid. The preserved samples were analyzed for their heavy metal (Ba, Cr, Cu, Fe, Mn, Pb and Zn) content, using inductively coupled plasma-mass spectrometry (ICP-MS). The results show that the average concentration of Ba, Cu, MN, Pb and Zn were above WHO guideline value for drinking water quality, hence not suitable for drinking. The average concentration of the metals is in the order Ba&gt;Mn&gt;Cu&gt;Fe&gt;Pb&gt;Zn&gt;Cr. Computed values of contamination index show that the samples from four locations were contaminated. Single factor pollution index computation indicates that the waters are not contaminated with Cr, but slightly polluted with Fe and Zn, moderately polluted with Ba and severely polluted with Cu, Mn and Pb. Further, Nemerow comprehensive pollution index indicates that samples from four locations were severely contaminated. The study revealed that the water sources around the barite mines had elevated level of heavy metal concentration compared to location around the quarries. It is recommended therefore, that the water be treated before use for drinking purpose.</p> <p><strong>Keywords:</strong> heavy metals, contamination index, pollution index, barite mine, quarry</p> I Ochelebe, E.A. Kudamnya, G.E. Nkebem Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/201241 Tue, 03 Nov 2020 00:00:00 +0000 Geochemical evaluation of Campanian-Maastritchian clay-shale sediments of Patti formation, Southern Bida and Mamu Formation, northern Anambra basins https://www.ajol.info/index.php/gjgs/article/view/201242 <p>Two basins (Southern Bida and Northern Anambra Basins) were investigated to deduce weathering, paleooxygenation, provenance, depositional environment and tectonic setting, as well as to establish a relationship between the two basins. The obtained high values of calculated weathering indices such as Chemical index of alteration (CIA &gt; 90), Chemical Index of Weathering (CIW &gt; 90), Plagioclase Index of Alteration (PIA &gt; 90) and the Al<sub>2</sub>O<sub>3</sub>-(CaO + Na<sub>2</sub>O)-K<sub>2</sub>O ternary relationship for the clay – shale sediments from both basins indicate intense weathering in the source area. Important geochemical ratios such as V/Cr, Cu/Zn, Ni/Co, (Cu+Mo)/Zn, revealed predominantly oxic conditions for the clay – shale sediments from both basins, although, a more reducing or an anoxic condition cannot be ruled out for the clay – shale sediments from the Southern Bida basin due to high ratios of U/Th (1.93-5.67) and Cu/Zn (0.19-5.00). In addition, the Sr/Ba ratios (0.16–3.50) for the clay-shales from the Southern Bida basin indicated an alternated marine and continental paleo-depositional settings and only continental setting (Sr/Ba ratios = 0.22 – 0.50) for the Northern Anambra basin. The Th/Sc, La/Sc, Th/Co and the LREE/HREE ratios showed a derivation of the shale and clay deposits from similar felsic-rich source rock while the log of (K<sub>2</sub>O/Na<sub>2</sub>O) vs SiO<sub>2</sub>, revealed a Passive Margin tectonic setting for the two Basins. There is insignificant differences between the geochemical classifications, weathering, source rock/provenance and tectonic settings of clay-shale sediments of both sedimentary basins, however, there exist slight disparity in their salinity conditions and redox settings.</p> <p><strong>Keywords:</strong> Geochemistry, Clay-shale, Provenance, Tectonic Setting, Northern Anambra and Southern Bida Basins</p> Nathaniel Odoma Atabo , Ojochogwu Idakwo Sunday Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/201242 Tue, 03 Nov 2020 00:00:00 +0000 Foraminiferal biostratigraphy and paleoenvironmental analysis of the sediments penetrated by Sahaiawei-1 well in the Northern Delta Depobelt, Niger Delta Basin https://www.ajol.info/index.php/gjgs/article/view/201243 <p>Foraminifera biostratigraphy and paleoenvironmental analysis of the sediments penetrated by Sahaiawei-1 Well in the Northern Delta Depobelt, Niger Delta Basin was carried out in order to determine the foraminifera biozonation, age, paleobathymetry, depositional environment and paleo-oxygen condition of the well. The total foraminifera population recovered was two thousand, three hundred and sixty five (2365), with planktic foraminifera constituting one hundred and fifty four (154) forms, while calcareous benthic and agglutinated benthic foraminifera recovered accounted for two thousand, one hundred and sixty two (2162) and fourty nine (49) of the total foraminifera population respectively. The total foraminifera species recovered was fifty nine (59); planktic accounted for twenty (20) foraminifera species, while calcareous and agglutinated benthic foraminifera accounted for thirty one (31) and eight (8) foraminifera species respectively. Five benthic foramineferabiozones were identified: lumped P7-P13, P5-P6/P7, lumped P3-P4, lumped P1-P2 and M18 Zones of Blow (1969, 1979). The result of the analysis indicates that the entire analysed interval (1800ft – 10680ft) was deposited during the Late Maastrichtian to Late Eocene epoch. The depositional environments of the Well varied from littoral, marginal, shallow and deep marine environments.</p> <p><strong>Keywords:</strong> Biozonation, Calcareous, Arenaceous, Agglutinated, Hyposaline Marshes, Hyposaline Shelf Sea</p> K Itiowe, F.A. Lucas, C.O. Olise Copyright (c) https://www.ajol.info/index.php/gjgs/article/view/201243 Tue, 03 Nov 2020 00:00:00 +0000