Compositional attributes of gold host rock and the significance of potentially toxic elements (PTEs) and their possible effects on human and ecosystem

The signatures of different compositions are very crucial in understanding the characteristics of geomaterials and it is much more important for gold, being a highly valuable economic material. The compositional attributes of gold host rock and the significance of potentially toxic elements (PTEs) and their probable effects on human and ecosystem have been investigated through geochemistry, mineralogy and toxic element (TE) analysis. Studying the significance of TEs is very important due to human exposure during mining and processing of the material as well as deposition of tailings into the environment consisting of soil, plant and water. The chemical composition is dominated by silica, alumina and hematite. While the silica content increases with depth, alumina and hematite reduce with depth owing to possible slight decomposition in the materials. Chromium, lead, arsenic, nickel, copper, zinc, barium, lanthanum, cerium, cobalt, rubidium and strontium are the toxic elements obtained. The gold in the host rock increases with depth. Quartz and feldspar are the most prominent minerals in the specimens. The geochemical indices variations with depths are variable but generally, the weathering in deeper strata is less and this could be linked to lesser intensity of chemical alteration in the gold host rock. The concentrations of lead, arsenic, nickel, copper and zinc are substantial in some specimens and this could cause adverse effects on human and the ecosystems. It is very essential to note that high concentration of gold attract high proportion of TEs. It is therefore necessary for the practitioners to investigate the presence or otherwise of TEs in these vital materials.