MINERALOGICAL AND GEOCHEMICAL STUDIES OF SANDSTONE IN IMOBI STUDY AREA AND ITS ENVIRONS, SOUTHWESTERN NIGERIA.

The combination of mineralogical and geochemical data of sedimentary rock can reveal the nature of source rocks, the tectonic settings of the sedimentary basins and the Paleoclimatic conditions. The aim of this research is to determine the geochemistry and mineralogy of the Imobi sandstones and to infer the provenance and possible depositional environment for these sand stones. Eight rock samples were collected from the study area, some portion were used for geochemical analysis to determine the chemical composition using X-ray fluorescence and the remaining portion were also used for mineralogical analysis to determine the mineralogical compositions and to estimate the modal percentages of minerals in the Imobi sandstone samples with the aid of the Petrological microscope. From the geochemical analysis, sixteen (16) elements and oxides were revealed and they includes SiO2, Al2O3, Fe2O3, CaO, V2O5, ZrO2, SO3, K2O, Br, P2O5, CuO, TiO2, MnO, Rb2O, As2O3, Cr2O3, while the mineralogical study show the presence of three minerals along with accessory minerals, they include quartz, iron oxide, microcline and accessory minerals. The presence of element and oxides like Br, V2O5, ZrO2, CuO, Rb2O, As2O3 and MnO (especially Br which occurred in a recognizable quantity of about 12%-27%) suggests the depositional environment of the Imobi sandstone to be a shallow marine or near marine environments.  However the abundance Of Fe2O3 infers the derivation of the sediments from a metamorphic source. The Petrography study reveals the presence of microcline, a feldspathic mineral commonly found in metamorphic rocks, and is consistent with the inference made from the geochemical composition that the provenance of these sandstones is from a metamorphic origin Key words: Geochemical, Sandstone, Aluminum, Bromine, Marine, Quartz, Provenance

PETROGRAPHY AND GEOCHEMICAL APPRAISAL OF AFOWO SANDSTONE FACIES, DAHOMEY BASIN, SOUTHWESTERN NIGERIA

Sandstones are sedimentary rocks formed by the cementation of sediment by material cements and they show a great deal of variation in mineral composition, degree of sorting and roundness. A petrographic and geochemical study of sandstones in the Afowo Formation of Dahomey basin southwestern Nigeria was carried out to infer the various elemental compositions, mineralogical composition, degree of sorting and degree of roundness of the sandstones in order to classify them. Seven (7) samples were collected and subjected to standard laboratory preparation and analytical method which include geochemical x-ray fluorescence for (trace and major elements analysis), and thin section petrography. The result of the geochemical analysis revealed the presence of some major elements (SiO2,Al2O3,Fe2O3,CaO,Br,and TiO2) and trace elements (V2O5,SO3,P2O5,CuO,MnO,Rb2O, and AS2O3) respectively. The mineral compositions obtained from the petrographical analysis are Quartz, Aluminum oxides, and high percentage of Iron oxides acting as the cementing material. The high percentage of Fe2O3 indicates that the sandstone is ferruginous while high concentration of Bromine ( Br) suggest a shallow marine environment of deposition of the sandstone. Key words: Petrography, Sand stone, Aluminum, Bromine, Marine, Quartz

Petro Chemistry of Major and Trace Elements Concentrations in the Stream Sediments of Awo Area and its Environs, Southwestern Nigeria.

Stream sediments are believed to record the environmental impact on fluvial system overtime and are often study to determine the overall pollution of an environment. This research work is aimed at mineralogical appraisal of various rock types through petro logical study, also to estimate the degree of enrichment of the element in the stream sediments and to determine if such enrichment has led to any form of pollution and also to produce a baseline geochemical data base for further geochemical investigation of the area under investigation. Ten soil samples were collected randomly within the study area and were analyzed for major and trace elements concentration using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) instrumentation techniques, while five rock types were selected for petro graphic studies. Thin section study shows that muscovite, biotite, microcline, and quartz are the main mineral assemblages present in the rocks of the study area. The result of the geochemical analysis were thereafter subjected to multivariate statistical analysis, the statistical plot from the result of major elements shows that Iron oxide (Fe2O3)  range from 9.30% - 1.60 %, with a mean value of 4.6865%. Aluminum oxide (Al2O3) range from 2.63% - 0.55% with a mean value of 1.6802%, Fe2O3 and Al2O3 are dominant major oxides within the study area and they show moderate enrichment in the environment under investigation.  From the result of the trace elements, Manganese [ Mn] with mean value of 3996.00 ppm, Zinc [Zn] with mean value of 272.40 ppm,  Copper [Cu]  with mean value of 628.10 ppm, Lead [Pb] with a mean value of 61.22 ppm, Nickel [Ni] with a mean value of 109.40 ppm and Cobalt [Co] with  mean value of  89.0 ppm have high concentration within the area of study, with Copper [Cu] having the highest degree of contamination factor 33%. The enrichment of Lead [ Pb] in the study area has been linked to anthropogenic  input of exhaust from motor bikes that ply the area, very strong positive correlation exist between V and Cr  (0.737), Co and Ni (0.648) while a positive strong correlation exist between Co and Cr (0.550), Mo and Ga  (0.535) indicating that they are from the same source. The conclusion drawn from the box plot study show that V, Cr, Co, Ni, Zn, Mn, As,  Rb,  Pb, Mo, Ga and Cd have values that are greater than zero, while Sr and  Zr have values that are less than zero. Copper [Cu] is the highest contaminating element within the study area, the presence of high amount of cupper in the study area may be probably due to geogenic factor, and in addition the  weathering of the associated rocks and precipitation of same within the environment and it can also be attributed to the mining operations going on in the study area; from this it can therefore  be deduced  that the study area range in the category of practically contaminated to moderately contaminated. Keywords: Sediment, Biotite, Enrichment, weathering, Geogeni

Strategic partnership of stakeholders: a veritable tool for sustainable fishery resources in Nigeria

Fishery resources are very important resource from the aquatic environment to the Nigerian economy. Stakeholders involvement in its management is highly important therefore, this paper proposes two frameworks against which sustainable fishery should be based, vis-a-vis stakeholders participation. The paper showed that decision-making involving stakeholders would enhance the goals of sustainable fishery development and create unity of purpose among various stakeholder

Simulation and Modeling of an Integrated Process Route for the Synthesis of Vinyl Chloride Monomer from Acetylene: Factorial Design Method and Artificial Neural Network

Vinyl Chloride gas is a nonirritating and colorless substance. It is usually colorless at a concentration lower than 3900 ppm (10,000 mg/m3). Vinyl Chloride is simply compressed to liquid for storage and shipping. At a concentration between 200 and 500 mg/m3, a Sweetish odor of Vinyl Chloride may be detected. This research paper is focused on the simulation of an integrated process route for the synthesis of Vinyl chloride Monomer from Acetylene via Aspen Hysys Simulation as well as the Factorial Design of the experiment with MINITAB 17.0. Fit Regression and Artificial Neural Network were employed for the modeling of the responses. Molar flow rates of acetylene (C2H2) and hydrogen chloride (HCl) predicts the conversions of acetylene and hydrogen chloride. A recycle unit is added to the process flow diagram and the maximum conversion of C2H2 and HCl is found to be 99.90 and 99.80 %, respectively. Analysis of variance (ANOVA) gives the results of the statistical correlation between the independent variables and response variables. The simulation and modeling results reveal that the Artificial Neural Network model gives better prediction and analysis of the process route with correlation coefficient (R squared values) of 97.921 % and 98.423 % for the conversion of C2H2 and conversion of HCl, respectively compared to the Factorial Design Method model with R squared values value of 79.47 % and 73.70 % for the conversion of C2H2 and conversion of HCl, respectively