Relief evolution of the Quadrilatero Ferrifero (Minas Gerais, Brazil) by means of (Be-10) cosmogenic nuclei
Résumé
This paper investigates the evolution of the relief within the so-called Iron Quadrangle (Quadrilátero Ferrífero) in Minas Gerais, Brazil, by means of quantification of erosion processes, which affected the principal rock types of the region. The method used is based on measurement of in-situ produced cosmogenic 10Be concentration in fluvial sediments. The results indicate that the regional landscape evolution is controlled by lithotypes: the most resistant areas correspond to substrates developed on itabirites and quartzites (long-term erosion rates between 0.29 to 2.35 m/My) and, whereas the most fragile ones developed on schist-phyllites (long-term erosion rates between 7.95 to 11.82 m/My) and granite-gneisses (long-term erosion rate at 12.92 m/My).