Anthropogenic isotope (Pb-210, Cs-137) variations in the sedimentary record from a lake in the Nahuelbuta mountain range, Chile.

The activity and distribution of Pb-210 and Cs-137 through the sedimentary record of a lake, which is located in the Nahuelbuta mountain range, are in fluenced by anthropic activity. Isotope analyses, X-rays, magnetic suscepti bility, pollen and grain size analyses show both erosion rates variations-p rod uc ed by land use changes within the watershed-and the Cs-137 atmospher ic inputs have affected on the behavior of those isotopes in the record. Th e role of some natural variables -as the low ratio of land to ocean in sout hern latitudes, and the Nahuelbuta mountain range locations are also discus sed.