Resumen
The activity and distribution of 210Pb and 137Cs through the sedimentary record of a lake, which is located in the Nahuelbuta mountain range, are influenced by anthropic activity. Isotope analyses, X-rays, magnetic susceptibility, pollen and grain size analyses show both erosion rates variations-produced by land use changes within the watershed-and the 137Cs atmospheric inputs have affected on the behavior of those isotopes in the record. The role of some natural variables -as the low ratio of land to ocean in southern latitudes, and the Nahuelbuta mountain range locations are also discussed.