Hydrological modelling of a Pleistocene landslide-dammed lake in the Santa Maria Basin, NW Argentina
Abstract Around 30,000 14 C yr BP, multiple landslides in the Quebrada de Cafayate (26°S, 66°W) dammed the Rio de las Conchas and caused a lake in the Santa Maria Basin, NW Argentina. Since climate could have played a major role in landslide generation, we used a lake-balance model to compare the present-day climate with the conditions during landsliding. This model reveals that a hypothetical present-day lake would stabilize around 70 m below the reconstructed paleolake level. The volume of the water body would be one third of the corresponding paleolake volume. However, a minimum 10–15% increase in mean-annual precipitation accompanied by at least a 3–4°C drop in temperature would result in a stable lake level at the reconstructed elevation. This result implies wetter and cooler conditions at 30,000 14 C yr BP as compared to the present. Wetter climate in turn could help to explain enhanced landsliding in the Quebrada de Cafayate during this time.