Akintola AI, Ikhane PR, Bankole SI, Adeokurolere DM
Petrographic studies and geochemical analysis were carried out on the rocks and stream sediments samples around Ede in Osun, Southwestern Nigeria, the study area fall in the coordinates N 07â°45’ - 07â°48’ and E004â°25’-004â°28’. This investigation was carried out in order to identify the rock units with their mineralogical appraisal and to determine the concentration and distribution of major and trace elements in the stream sediments with a view to elucidate the mineral potentials of the study area. Five (5) rock samples were selected for thin section, which was then subjected to petrographic studies Ten (10) stream sediments were also collected for determination of all possible elements using inductively coupled plasma (ICP AES) Instrumentation technique. Geological mapping of the study area on the scale of 1:50,000 reveal three rock types which are pegmatite, banded gneiss and biotite gneiss. Petrographic studies show that Quartz, Plagioclase, Microcline, Biotite, and opaque minerals are the main mineral constituents under the transmitted light. The analytical results reveal major oxide Feâ�?�?Oâ�?�? to range from (0.70-3.32%) with a mean value of 1.69%, Alâ�?�?Oâ�?�? ranges from (0.34-2.87%) with a mean value of 0.94% and Caâ�?�?O ranges from (0.03-0.42%) with a mean value 0.17%. Some of the trace elements analyzed for include; Mn, Cr, V, Zn, Cu, Pb, Co, Rb, Sr, Ni, Y, Ga, Zr, As and Mo. Manganese [Mn] ranges from (225.0- 946.0ppm) with a mean value 541.0ppm, Cr ranges from (16.6-59.3ppm) with mean value of 33.2ppm and V ranges from (12.0-52.0ppm) with a mean value of (27.9ppm). This could be attributed to its underlying geology (rock types). Location 8 has the highest level of cumulative metal enrichment (1027.89%) while location 3 has the least level of cumulative metal enrichment (0.67%). It can therefore be inferred that from various geochemical parameters used, there are indications that the stream sediments from the study area, are showing low contamination factor (Cf<1). Indicating low contamination with respect to V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Mo, Rb, Sr, Y, Zr and Pb. The degree of contamination is calculated to be 3.50°. Manganese [Mn] contributed most to the overall degree of contamination index with a value of 65.83°.
Share this article