An overview of trace elements in soils of Keana-Awe Brine-Fields, Middle Benue Trough, Nigeria

The objective of this study was to determine the concentration of trace elements in soils of Keana-Awe brine-fields. Composite soil samples were randomly collected at a depth of 0–15 cm and were analysed for molybdenum, zinc, arsenic, lead, cobalt, chromium, copper, barium and nickel using Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Quantification of the degree of soil contamination by these trace elements was carried out using the enrichment factor (EF) and the geo-accumulation index (Igeo). The data were subjected to principal component analysis (PCA). The average concentrations were 1.56 ppm molybdenum, 1116.42 ppm zinc, 23.80 ppm arsenic, 71.40 ppm lead, 17.64 ppm cobalt, 237.35 ppm chromium, 24.16 ppm copper, 254.67 ppm barium and 143.71 ppm nickel. Cobalt, nickel and chromium showed positive loadings in component 1 with a total variance of 29.56%. Zinc, copper and lead showed positive loadings in component 2 with a total variance of 18.79%, while copper showed negative loading in component 3 with a total variance of 14.79%. Considering the concentration of trace elements in the soils and statistical analyses, we conclude that soils of the study area were severely enriched in molybdenum, cobalt, chromium, copper, barium, nickel, while arsenic and zinc are in excessive concentrations in the soils. These trace elements could have originated from geogenic and anthropogenic sources.DHE

Age control and designation of the standard stratotype of Nsukka formation of Anambra Basin, Southeastern Nigeria

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Petrography And Mode Of Formation Of The Oolitic Ironstone Beds In The Campano-Maastrichtian Nkporo Formation In Leru, Southeastern Nigeria

The dark grey to black Nkporo Formation (Campanian – Maastrichtian) exposed in Leru area, southeastern Nigeria, contains several interbeds of oolitic ironstone in the upper parts. The ironstone consists of calcareous groundmass with pockets of unevenly distributed ferriferous ooids. The ooliths are “egg”- shaped and vary between 0.50 mm and 1.50 mm in diameter. From thin section studies, the oolitic ironstones are comprised of framework grains of chamosite ooliths in siderite cement and secondary limonite. The spheroidal shapes, absence of radial shrinkage fractures, lack of relict textures, and clean and clear, near-perfect cortices are indices of primary precipitation of the ooliths on the sea floor. The poor winnowing and presence of intact shell fragments indicate their deposition in a low energy environment. Concentric chamosite accretion on the nuclei developed while the nuclei were under low hydrodynamic turbulence on the sediment-water interface. Keywords: Petrography, Chamosite ooliths, Oolitic Ironstone, Primary precipitation, Diagenetic replacementGlobal Journal of Geological Sciences Vol. 6 (1) 2008: pp. 57-6

Hiv infection prevalence among women visiting the Hiv counselling centre in Nnewi, Nigeria.

Objective: This study is aimed at determining the HIV prevalence rate among women attending the HIV counselling & testing centre at Nnewiand the effect of marital status on this.Method: This is a retrospective review of the records of women visiting the HIV counselling and testing (HCT) centre of the Nnamdi AzikiweUniversity Teaching Hospital from July 2004 to June 2005 to determine their HIV status. They include women attending antenatal clinic,premarital test, pre employment test and those referred from other centres for confirmation of their status. The data was analysed and presented in tables using comparative percentages.Results: HCT uptake during this period was 87.6% (1419/1620) while HIV sero-prevalence was 28.3% (402/1419). The breakdown of thefemale population showed a 15.3% (70/458) sero-positivity among pregnant women, 25.8% (69/268) sero-positivity among single non-pregnant girls and 38.0% (269/693) sero-positivity among married non-pregnant women. The 25 – 29 years age range had the highest sero-prevalence for HIV infection though there was no significant difference in prevalence of HIV infection for women above 20 years of age. However, the adolescents (15-19 years) had a significantly lower prevalence (