Groundwater infiltration in a gold mine–A geoelectrical investigation model as an aid to dewatering process determination

Abstract

Mineral resources are fundamental to the existence of mankind and their exploitation is synonymous with progress and advancement since ancient time. The twenty-first century is characterized by heightened concerns for Earth's water resources. Preservation and reuse in a sustainable way is one of the main goals of the population in the present day. Mining of renewable and non-renewable energy resources usually occurs through underground mines or open pits, some of which, when developed below the water table, cause intensified sub-surface water infiltration and percolation. In cases where the volume of water is relatively large, there are financial losses and delays in mining activities. Considering this, there is a need for more subsurface geologic and structural investigations with the aim to characterize the recharge zone areas, main pathways and concentration for subsequent solution of water infiltration. The present study suggests the use of the DC resistivity geophysical method for the characterization of the galleries surrounding a fully functioning underground mine in the municipality of Faina, Goiás State, Brazil. A total of 12 resistivity profiles in the area, along with inversion interpretation and analysis provided a three-dimensional conductivity/resistivity visualization (geoelectrical model) integrated with the locations of underground galleries. The results show significant resistivity contrasts (anomalous low electrical resistivity) associated with water inflows, recharge zone, water accumulation and its related subsurface structures. The study is an effective approach that helps to locate drainage pumps for optimizing the dewatering process. It also provides useful subsidy information for a better and more comprehensive hydrogeological model in the area.