The present work quantifies the erosive processes in the two main substrates (schists-phyllites and granites-gneisses) of the upper Maracujá Basin in the Quadrilátero Ferrífero/MG, Bra- zil, a region of semi-humid tropical climate. Two measuring methods of concentration were used: (i) in situ produced 10 Be in quartz veins (surface erosion rates) and (ii) 10 Be in fluvial sediments (basin erosion rates). The results confirm that (i) erosion tends to be more aggres- sive close to the headwaters than in the lower parts of the basin and (ii) the region is now affected by dissection.
