42 research outputs found
Pyrolytic and provenance evaluation of organic matter from the tertiary niger delta basin, nigeria: implication on hydrocarbon generation.
The present work deals with evaluation of organic matter based on detailed Rock-Eval pyrolysis techniques studies to evaluate hydrocarbon generation potential of source rocks by collecting twenty- nine shale samples from well cuttings in the Tertiary Formations of the Niger Delta, Nigeria. The values of vitrinite reflectance (0.57–0.74%Ro) and maximum (Tmax: 420–445°C) confirmed that samples are at early maturity to matured stage enough to generate liquid and gaseous hydrocarbon. The cross-plot between hydrogen index (HI) and oxygen index (OI) atomic ratio indicates that samples were predominant in the bituminous rank and having kerogen Type III makes it suitable for hydrocarbon generation. Rock-Eval pyrolysis analysis (Types II-III and Type III kerogen) on shale samples from the Niger Delta reveals organic matter of predominantly terrestrial origin based on type III kerogen. The organic matter (OM) assemblages suggests a marine setting but dominated by terrestrial inputs likely related to fluvial processes which is function of most delta system. Based on high total organic carbon (TOC) value of 5.42wt% and Type III kerogen made the shale an excellent source rock, with gas-prone kerogen. The high OI, low total sulphur (TS) suggests terrestrially derived OM and deposition in an oxic and dysoxic shallow marine environment. In addition, HI and Tmax values describe the samples as a characteristic Type III dominant kerogen and potential to generate oil and gases while the Tmax, consistently indicate an immature to mature on the shale organic matter
Structural framework and deformation episodes in the igarra schist belt, southwestern nigeria
The structural framework of the Igarra schist belt consists of brittle (mainly fractures) and ductile (foliation, cleavage, folds, lineations, strain markers) structures. The geometry of these structures reveals two major occurrences of transpressional deformation affected the schist belt. These are an older dominantly ductile deformation with NW–SE λ1 which developed foliations, cleavage, folds, and mineral/stretching lineations deforming only the metasediments and a younger brittle–ductile, E-W tectonic shortening deformation which closed deformations in the Igarra schist belt, deforming both the metasediments and granitoids, producing almost all the brittle structures in the belt. Minor fracture trends which are not associated with any of the major episodes of deformation and E-W transposition foliation in marble and gneisses constitute a relic of an unconfirmed possibly older episode of deformation. Ductile and semi-brittle shear zones in the Igarra schist belt are few and usually occur on small scale (outcrop scale), hence, they do not constitute a major episode of deformation. Mineralizations in the Igarra schist belt are pegmatite and quartz which are emplaced mainly in fractures with industrial minerals like marbles
Api gravities and geochemical evaluation of crude oils from sapele, niger – delta, nigeria
The investigation is to provide information on source organic matter input, depositional conditions and the correlation between crude oils recovered from Sapele oilfield in the Niger Delta. A suite of twenty-five crude oils from the Agbada reservoirs (synsedimentary) of the Tertiary Niger Delta (Southern Nigeria) were analysed based on API gravities and geochemically compared with extracts from source rock of the Akata and Agbada Formations. The Sapele shallow reservoirs occur between the depths of 4000ft and 6000ft, containing heavy crudes with API gravities 20 – 22 degrees. The deep reservoirs lie within 7000ft and 12000ft accumulating the light crudes with API gravities of 24.70-35.60 degrees, and viscocity of 1.64cP. The investigated biomarkers indicated that the Sapele oils were derived from mixed marine and terrigenous organic matter and deposited under suboxic conditions. This has been achieved from normal alkane and acyclic isoprenoids distributions, terpane and sterane biomarkers. These oils were also generated from source rock with a wide range of thermal maturity and ranging from early-mature to peak oil window. Based on molecular indicators of organic source input and depositional environment diagnostic biomarkers, one petroleum system operates in the Niger Delta Region; as observed on the source rocks from the Agbada organic – rich shale sediments. Therefore, the hydrocarbon exploration processes should be concentrating on the Akata and Agbada area of the Tertiary strata for determining the source kitchen
Malaria in Pregnancy in Nigeria: A Literature Review
Malaria is caused by the parasite plasmodium which can be spread to humans through the bite of an infected mosquito. Of the five types of plasmodium (P. Falciparium, P.Ovale, P. Malaria, P. Vivax and P. Knowlesi), the plasmodium falciparium is the deadliest and affects the lives of almost 40 per cent of the world’s population with pregnant women and children under-five years of age being the most affected. This mini-review involved the collation of findings from recent studies in regards to the prevalence of malaria infection among pregnant women and infants. A systematic analysis of recent literature on the prevalence of malaria in pregnancy from many authors was carried out and the facts synthesized to make an easy read. From the analysis of literature, Ten Thousand women and 200,000 babies were reported to be dying annually from complications of malaria in pregnancy which recorded a prevalence of 85 per cent in sub-Saharan Africa. More so, Fifty per cent of pregnant women were discovered to be carrying plasmodium falciparium in their placenta without even experiencing malaria signs/ symptoms, and this development was reported to have been responsible for Twenty per cent of stillbirths and 11 per cent of all maternal deaths. Malaria infection is considered a major threat to the lives and well-being of pregnant women and infants. Therefore, stakeholders should ensure that every clinical diagnosis of malaria in pregnancy is confirmed with a laboratory plasmodium falciparium-based diagnosis before the administration of antimalarial drugs. Furthermore there should be a stepping –up on the distribution of insecticide treated nets alongside enlightenment of pregnant women on ways of preventing mosquito bite. Instituting the aforementioned approaches is key to improving the health- seeking behaviour of pregnant women in particular and the wider population in general thus enabling them to stay malaria free throughout the period of pregnancy and infancy
Multi-element association and regional geochemistry of protoliths in tashan jatau area, northwestern nigeria: implications for gold exploration
Soil geochemical surveys are widely used in the early stages of gold exploration, especially in areas with poor outcrops and thick overburden. Fifty-one (51) soil samples were collected in duplicate with the aim of analyzing them geochemically and determining the gold grade through panning and weighing methods. The geochemical results were subjected to multivariate statistical treatment through Factor analysis and Pearson correlation matrix. Four factors were generated from the PCA. These are Factor 1: Cu-Sr-Nb-Ba-La-W-Pb-Zr, suggesting sulfide mineralization that is related to granitic rock while Factor 2 has Au with a low to negative correlation with Mo and Nb suggesting a second phase of intrusion-related activity which must have emplaced gold in this area. Factor 3 is made up of W-Pb suggesting a second sulfide mineralization distinct from the first. While Factor 4 gives a single element factor, Hg. Single-elementt maps were constructed to show the element dispersion in the catchment. In general gold concentrations in this study is erratic and attain a high of 0.67ppm and 0.90g/t. The study delineates the northwestern part of the catchment to be the most prolific in terms of gold potential and shows that the granitic batholiths are the most primary gold-hosting lithology.
 
Trace element geochemical imprints and multi-path health risk assessment of potentially toxic elements in soils from the polymetallic area of tashan-jatau, northwestern nigeria
The occurrence of Potentially toxic elements (PTEs) in the soil phase may portend environmental, ecological and health-related risks. Hence, this study has combined high-precision geochemical analyses (X-ray fluorescence (XRF) and inductively Coupled Plasma Mass Spectrometry (ICP-MS)), quantitative soil pollution indices and health risk assessment modelling for a holistic and precise assessment of the intrinsic vulnerability of the soil system to contamination. Geochemical analysis showed that the soils are highly enriched with PTEs such as V (mean = 449.5 mg/L), Cr (mean = 529.9 mg/L), Cu (mean = 374.4 mg/L), Sr (mean = 1365.3 mg/L), Zr (mean = 2703 mg/L), Zn (mean = 282.5 mg/L), and Pb (mean = 127.3 mg/L). Quantitative soil pollution assessment (contamination factor and enrichment factor) revealed that besides mining, the distribution and association between trace elements and oxides were from surface environmental conditions (including mobility potential, leaching metal-complexation, weathering and oxidation of parent material). Health risk assessment based on hazard quotient and hazard index revealed that the inhabitants are generally more exposed to risks from toxic elements ingestion than dermal contact and inhalation; the children are vulnerable to risks than adults. The cancer risks from ingestion and dermal contact of As and Cr for both children and adults are relatively higher (> 1.0E−04) than the acceptable range; although the children population seems to be more susceptible to cancer risks due to lower body weight.
 
REFUGEE INFLUX: A SOCIOLOGICAL INSIGHT AND EMPIRICAL ANALYSIS OF ITS CONCOMITANT EFFECT ON FOOD SECURITY IN ETUNG CROSS RIVER STATE, NIGERIA
The study examines the impact of Cameroun refugee influx and its impact on food security in Etung Local Government Area of Cross River State, Nigeria. The study adopted the survey research method in eliciting information from 400 samples from two political wards in Etung Local Government Area of Cross River State, Nigeria, using the purposive and random sampling technique. a self-administered structured questionnaire was the instrument of Data collection. Data gathered from the field was meticulously collated, coded and analyzed using simple percentages, frequency distribution, figures and simple lineal regression at 0.05 confidence level. Result revealed that there is a significant relationship between refugee influx and Food Security in Etung Local Government Area of Cross River State, Nigeria. The study recommends That the Cross-River state synergizes with the relevant agencies of the Federal Government as well as other international Agencies to stimulate production in Etung through agricultural programs such as farmers smallholders schemes, cassava, banana, yam, plantain plantations schemes, animal husbandry, cottage industries etc. to promote aggressive food revolution within affected areas to avert serious food crisis amongst others. Article visualizations
Field Observations and Geophysical Research Applied to the Detection of Manganese (Mn) Deposits in the Eastern Part of Oban Massif, South-Eastern Nigeria: An Integrated Approach
The growing need for an industrialized world, especially in Africa, cannot be feasible without adequate mineral resources. Thus, the search for more mineral deposits will continue to be necessary. An integrated approach involving geological mapping and a high-resolution geophysical
(aeromagnetic) investigation was conducted to assess the manganese mineralization in parts of the Oban Massif, southeast Nigeria. The aeromagnetic data were processed using regional-residual anomaly separation techniques, first vertical derivative (1VD), analytical signals, source parameters imaging (SPI), and Euler deconvolution to better understand magnetic source distributions and their
depths of occurrence. The geological investigation revealed a dominant variety of metamorphic rock types, including migmatitic (banded) gneisses hornblende granite gneisses, amphibolites, charnockites, and some quartzite ridges. Also present are some indications of pockets of dolerites. The study area also observed epithermal Mn+Fe+Qtz vein type mineralization associated with hydrothermal alteration zones whose orientation coincides with dominant structural orientation from aeromagnetic interpretation. Analysis of aeromagnetic data shows that the study area is dominated by ENE, NNE, and E-W structural directions (near-surface basement structures), with the ENE trends related to
mineralization in the area. The manganese mineralization within Oban Massif is structurally controlled. The depths of the magnetic anomalies in the study area were estimated using SPI and Euler decomposition algorithms. SPI delineated the shallow, intermediate, and deep magnetic anomalies
at 84–142 m, 152–200 m, and 215–656 m, respectively. Euler decomposition, however, revealed that shallow, intermediate, and deep depths occurrence of the magnetic anomalies are at 200–377 m, 393–472 m, and 499–793 m, respectivel
Field Observations and Geophysical Research Applied to the Detection of Manganese (Mn) Deposits in the Eastern Part of Oban Massif, South-Eastern Nigeria: An Integrated Approach
The growing need for an industrialized world, especially in Africa, cannot be feasible without adequate mineral resources. Thus, the search for more mineral deposits will continue to be necessary. An integrated approach involving geological mapping and a high-resolution geophysical
(aeromagnetic) investigation was conducted to assess the manganese mineralization in parts of the Oban Massif, southeast Nigeria. The aeromagnetic data were processed using regional-residual anomaly separation techniques, first vertical derivative (1VD), analytical signals, source parameters imaging (SPI), and Euler deconvolution to better understand magnetic source distributions and their
depths of occurrence. The geological investigation revealed a dominant variety of metamorphic rock types, including migmatitic (banded) gneisses hornblende granite gneisses, amphibolites, charnockites, and some quartzite ridges. Also present are some indications of pockets of dolerites. The study
area also observed epithermal Mn+Fe+Qtz vein type mineralization associated with hydrothermal
alteration zones whose orientation coincides with dominant structural orientation from aeromagnetic
interpretation. Analysis of aeromagnetic data shows that the study area is dominated by ENE, NNE,
and E-W structural directions (near-surface basement structures), with the ENE trends related to
mineralization in the area. The manganese mineralization within Oban Massif is structurally controlled. The depths of the magnetic anomalies in the study area were estimated using SPI and Euler decomposition algorithms. SPI delineated the shallow, intermediate, and deep magnetic anomalies
at 84–142 m, 152–200 m, and 215–656 m, respectively. Euler decomposition, however, revealed that shallow, intermediate, and deep depths occurrence of the magnetic anomalies are at 200–377 m, 393–472 m, and 499–793 m, respectively