The Quadrilátero Ferrífero region, in the State of Minas Gerais, became internationally known due to the exploitation of gold in the eighteenth century. In this paper, we will present background values for arsenic in alluvial sediments from areas that were heavily affected by the exploitation of gold in the past, in the Carmo River Basin. The analyses of the facies succession of the alluvial profiles were carried out in the sedimentary deposits of flood plains, cutbank and alluvial terraces; this being the foundation for obtaining the arsenic background in the facies of the channel and flood plains. From the knowledge of the background obtained by the statistical method, and based on the construction of cumulative frequency curves on a linear scale, geochemical maps were generated in the SIG system. The acquisition of the background values and the geochemical map for arsenic in the Carmo River Basin, representing areas with anomalous concentrations of this element, are essential for the diagnosis and environmental planning of a mining district potentially contaminated by arsenic.
Background; arsenic; sediments; flood plains; alluvial terraces; Quadrilátero Ferrífero
