Geochemistry and mineralogy of soils around Atok, Limpopo Province, South Africa

Abstract

Mining activities for mineral resources over the years have, according to certain people, resulted in soil damage in the Atok area because of huge amounts of waste earth and rock that was brought to the surface, this waste often becomes toxic when it comes into contact with air and water. However, the geology of the area which is mafic in composition has caused major damage to the soil in the area as well. Due the removal process of desired mineral materials, soil textures have been destroyed, various nutrient cycles disturbed, and microbial communities altered, changing the vegetation and leading to the format of land in the area. Therefore, soil restoration of mining lands became a very important part of sustainable development strategies and also prescribed by law in South Africa. The geochemistry and mineralogy of soil samples taken from the area of Atok were studied using X-Ray Fluorescence (XRF) and physio-chemical parameter analysis. These methods are used for investigating the element and mineral associations and the distribution of heavy metals in these soils around the mine. The chemical and mineralogical data from soil and tailings were collected from each of the following areas around Atok: (Sefateng, Moonametsi, Mohlahlaneng, Sefateng Tailing Dam and Mafeo), the samples were collected at various depths; at each sampling points. The results of XRF analysis indicated that the soils are rich in MgO, CaO and Fe2O3 with minerals such as pyroxenes, plagioclase feldspar and occasional olivine being dominant. An excess of these minerals caused the soil to be infertile. The physio-chemical analysis showed that the soil texture is sandy, therefore this is the reason that the soil has low water holding capacity (27%) and low soil moisture (1.2%), the pH (8.50) and EC (<0.50 dS/m). Keywords: Soil composition, chemical properties, heavy metal, contamination.