Quantifying rates of paraglacial sedimentation: an example from Chilean Patagonia

Debris cones are a typical geomorphic consequence of sediment mobilisation following glacier retreat. Whereas chronological controls for paraglacial debris cones of Late Glacial and early Holocene age are rarely refined enough for process rates to be estimated, formation rates of recently formed cones can be quantified. This paper quantifies the accumulation rate of a debris cone formed in the Nef Valley, Chilean Patagonia, by the resedimentation of morainic material since the retreat of Glaciar Nef around 1863. Soiric 17,800 m(3) of material has been moved mainly by debris flows and snow avalanches representing a minimum mean sedimentation rate of 132 m(3) a(-1).