Geochemical investigation of gold and chalcophile minerals of Rawayau Area Katsina State, Nigeria

This present study investigated the Gold and Chalcophile mineralisation potentials of the Rawayau area in Northwestern Nigeria. The aim of the investigation is to delineate the likely Gold and Chalcophile mineralisation occurrences in the study area so as to aid further exploration studies that will identify Gold rich targets worth investing resources for detail exploration project before mining. To achieve this, 17 samples (7 rock samples and 10 sediments) were collected and subjected to laboratory analysis at the National Geologic Survey Agency (NGSA) in Kaduna. The geochemical study showed that the Au concentration ranged from below detection level (bdl) to 0.09ppm in the rock samples, while ranging from 0.013ppm to 0.137ppm in the sediments. Ag concentration ranged from 0.37ppm to 0.97ppm with in the rock samples, while ranging from 0.088ppm to 0.229ppm in the sediments, thus showing a higher concentration in both rock and sediments than Au. Significant positive relationship was observed between Ni, Cr, Cu, Mn, Fe, Zn and Co from the correlation analysis. It also revealed a subsurface increment of Gold and Chalcophile concentration of Nickel, Copper and Zinc with higher concentration of Nickel, Copper, Zinc, Manganese, Chromium and Lead in comparison to Gold and Silver. The study concludes that the Rawayau area holds much prospects for Gold and other minerals. It is suggested that further exploratory studies be carried out so as to pave way for the commencement of mining activities in the study area”

Provenance Studies of Alluvial Tin Deposits in Parts of Ropp Younger Granite Complex, North Central Nigeria

The study area in this research is within the Ropp Complex, part of the Nigerian Mesozoic Younger Granite province. The study aims to interpret the depositional environment and establish the provenance of the alluvial cassiterite deposits in the study area. Boreholes/mining pits were logged for this study, and stanniferous sandstone samples were collected, which were used for textural and mineralogical studies. The mineral assemblages documented in the samples include ilmenite (3% to 27%). Cassiterite (2 to 14%), Zircon (2 to 16%), magnetite (0 to 17%), tourmaline (5 to 11%), rutile (2 to 8%) and monazite (2 to 7%).The ZTR Index calculated from the result of heavy minerals analysis for the selected pieces is 59%. Mineralogical studies revealed that quartz is the most dominant detrital mineral averaging about 93-99%, indicating that the stanniferous sandstones are compositionally matured and have experienced a high degree of chemical weathering. The quartz grains have grain sizes ranging from coarse to very coarse. They are poorly sorted, sub-angular to sub-rounded, with low sphericity. This also indicates a closeness to the source and textural immaturity. The occurrence of relatively very few feldspar grains suggests a slow sedimentation rate, very high rate of chemical weathering and composition maturity. The bivariate plots, univariate grain size parameters and probability plots, and the absence of fossils and trace fossils suggest deposition in a fluvial environment. The results of the granulometric analysis indicate that the study area's stanniferous sandstone was deposited in a fluvial environment by a low-energy fluvial (river) depositional system and the deposition in proximal (close to the source). This study suggests that the Basement complex and Younger Granite are the sources of the stanniferous placer deposits

The effect of cement replacement with metakaolin and sugarcane bagasse ash as supplementary cementitious materials on the properties of concrete

The use of supplementary cementitious materials in the cement and construction industry is growing rapidly owing to the numerous benefits the application of these materials offers. In this study, the effects of metakaolin (MK) and sugarcane bagasse ash (SCBA) used to partially replace cement on concrete are investigated. The experimental plan was designed using a constant 5% MK and 0-20% SCBA contents by weight. The mix design of 1:2:3 and water-binder (w/b) ratio of 0.5 was employed. Samples prepared were tested at the ages of 7, 14, 28, and 60 days respectively. Concrete workability, water absorption, and densities all showed a decrease with an increase in the percentage of SCBA. The compressive strengths at lower percentages of SCBA (5% and 10%) recorded higher values compared to that of 5% MK and 0% SCBA. An increase in the percentage of SCBA above 10% however led to a decrease in compressive strength. The maximum compressive strength of 22.17N/mm2 was obtained at 60 days in concrete containing 5% MK and 10% SCBA. Both the T-statistics and F-statistics values calculated were statistically significant and exceeded their critical values. This suggests that there is a good relationship between the compressive strength of SCBA and the curing period and that the variation in the curing period and SCBA also causes a variation in the concrete compressive strength. From the results obtained, it is concluded that 5% MK and 10% SCBA can be applied to replace cement for structural concrete production