Vol.:(0123456789) 1 3 Environmental Earth Sciences (2019) 78:167 https://doi.org/10.1007/s12665-019-8158-7 ORIGINAL ARTICLE Impacts of mining in artifcial lake of Iron Quadrangle-MG: past marks and changes of the present Larissa Paraguassú 1  · Mariangela G. P. Leite 1,2,3  · Francisco W. A. Moreira 3  · Fellipe P. C. Mendonça 1,4  · Eneida M. Eskinazi‑Sant’Anna 1,3,5 Received: 3 April 2018 / Accepted: 16 February 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract A locus of intense mining activity since the seventeenth century, the Iron Quadrangle, corresponds to one of the most impor- tant mineral provinces in the world. Located in Minas Gerais, Brazil, it keeps in its territory marks of past mining activities still in expansion. Such changes, recorded in water bodies of the region’s watersheds, impact not only locally, but also reach adjacent ecosystems as well as those located downstream of mining companies. In this situation, an artifcial lake is found in the upper course of the Mata Porcos creek sub-basin. The area was once an old place of gold exploration in the eighteenth and nineteenth centuries, and is currently infuenced by active iron mining and inactive iron–manganese mining upstream. With the aim of evaluating this reservoir and contributing to the understanding of lentic systems under the infuence of mining, this study analyzed the physical and chemical characteristics of sediments from the bottom of this lake, identifying the possible contributions of anthropic origin. Sediment samples were collected at nine points along two hydrological years and then submitted to granulometric, mineralogical and geochemical analyses. The geochemical signature of this lake is marked by As, Fe and Mn elements associated with both the local geological substrate and anthropic activities undertaken in the surroundings. Due to the high As concentrations, distribution maps were made using the IDW interpolation method to understand the distribution of this potentially toxic element that has a strong correlation with gold mining practiced for more than 300 years at the site. Keywords Mining impacts · Iron Quadrangle · Artifcial lakes · Arsenic · Sediments · Environmental geochemistry Introduction Of recognized socioeconomic importance, mining is a booming economic activity that has been associated with numerous environmental impacts around the world. Because it is a type of temporary land use, it is difcult to precisely predict its impacts, in both temporal and spatial domains (Bridge 2004; Zhang et al. 2017). In general, mining regions have mineral resources that are abundant and economically accessible and, therefore, often suffer rapid and exten- sive changes in land use (Bridge 2004). Such changes are largely associated with changes in the local landscape and generation of large amounts of waste and efuents, which may afect both mined and adjacent areas (Lechner et al. 2017), sometimes culminating in signifcant geochemical changes along the watershed in which the intervention area is inserted, with contamination of water, soils and sediments that may continue to impact the environment, even decades Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12665-019-8158-7) contains supplementary material, which is available to authorized users. * Larissa Paraguassú larissaparaguassu@gmail.com 1 Graduate Program in Crustal Evolution and Natural Resources, Federal University of Ouro Preto, Ouro Preto, Minas Gerais 35400-000, Brazil 2 Department of Geology, Federal University of Ouro Preto, Ouro Preto, Minas Gerais 35400-000, Brazil 3 Graduate Program in Tropical Biomes, Federal University of Ouro Preto, Ouro Preto, Minas Gerais 35400-000, Brazil 4 Minas Gerais State Forestry Institute (IEF), Itacolomi State Park, Ouro Preto, Minas Gerais 35400-000, Brazil 5 Department of Biodiversity, Evolution and Environment, Federal University of Ouro Preto, Ouro Preto, Minas Gerais 35400-000, Brazil