Tracing the impact of glacial-interglacial climate variability on erosion of the southern Andes

Sediment accumulation rates of well-dated, primarily terrigenous marine sediments collected along the Chilean continental margin were used to infer erosion rates of the southern Andes and the adjacent Coastal Cordillera. Compared to the Holocene, sediment supply to the margin and thus erosion were substantially enhanced during the last glacial, when continental rainfall in the region was higher. Major changes in precipitation forcing to the southern Andes on such glacial-interglacial time scales appear to be transferred to offshore sedimentation rates by a fixed relation. These data show that marine archives can make it possible to trace variability in erosion at adjacent continents on time scales to [10.sup.3] yr, a much better resolution than provided by commonly used methods such as thermochronometry or seismic studies. Keywords: marine sediments, erosion, climate change, Andes, southeast Pacific, precipitation.