Petrography and Geochemistry of Neoproterozoic Sandstones of the Northeastern Parts of the Voltaian Basin of Ghana: Implications for Industrial Usage

Sandstone is a source of silica sand for the production of a wide variety of glass. The northeastern parts of the Voltaian Basin of Ghana have a wide distribution of quartzitic sandstones whose industrial usage prospects have not been assessed. For the first time, this study evaluates the probable usage of the sandstones within this area as silica sands for the production of glass based on the petrographic and major oxides assessment. The sandstone samples studied are medium to coarse-grained with angular to sub-rounded textures. The mineralogy of the sandstones is predominantly quartz with grain-supported and silica matrix fabric, with evidence of quartz overgrowth. The dominant oxide from the whole rock geochemical study is SiO2, with an average value of 93.31 %. The mean concentrations of the other major oxides – Al₂O₃, K₂O, Fe₂O₃, MgO, CaO, and Na₂O – are 2.90%, 0.93%, 0.84%, 0.09%, 0.04%, and 0.04%, respectively. The sandstones are moderately altered, with the chemical index of alteration (CIA) mean values of 67. This is supported by compositionally immature sediments with an index of compositional variability (ICV) mean value of 1. The SiO2/Al2O3, however, shows that the sediments are compositionally mature or from a close silica-rich source rock. Given the levels of SiO₂, Al₂O₃, MgO, CaO, and Na₂O, the sandstones have not met the world standards for quality glass production, they have the potential for use as silica sand in the production of soda-lime silica containers and glass fiber. The relatively high concentrations of Al2O3 and Fe₂O₃ as impurities could be reduced while increasing the SiO2 levels through beneficiation techniques, to meet world-glass chemical specifications. A comprehensive evaluation of these sandstones by relevant stakeholders, including the Ghana Geological Survey Authority, is strongly recommended due to their potential to contribute significantly to the national economy.