LATE PLEISTOCENE CLIMATE CHANGE AND EROSION IN THE SANTA MARIA BASIN, NW ARGENTINA

ABSTRACT: Present erosion and sediment flux in the semiarid intra-montane Santa Maria Basin, NW Argentina, are compared with con-ditions during a period of wetter and more variable climate at about 30,000 14C yr ago. The results suggest that the influence of climate change on the overall erosional sediment budget is significant, mainly because of a change in the erosion regime coupled with an increase in mass movements. The most effective mechanism to increase landslide activity in this environment is a highly variable climate on interannual timescales. In contrast, Quaternary changes in erosional budgets due to variations in moisture regimes is small in the Santa Maria Basin. Because the magnitude of a potential increase in background erosion as well as enhanced landsliding is smaller than typical levels of uncer-tainty of erosional budgets for such large basins, it is not likely that climate-driven erosional unloading can influence tectonic style and rates in this semiarid environment on time scales of several thousands to a few tens of thousands of years