Late Pleistocene detrital sediment yield of the Jura glacier, France

Measures of present-day glacial erosion vary widely with the technique empl oyed. This paper quantifies the glacial material trapped in a proglacial la ke during the Wurm glacial period. The Combe d'Ain site was occupied by a m eltwater lake where all the detrital material entering it from the Jura gla cier accumulated, Sediment yield is computed from three factors: (1) the si ze of the sediment source area, (2) the length of time the system operated, and (3) the volume of sediment trapped. The sediment budget of the lake sy stem suggests a detrital sediment yield of 4400 +/- 1700 metric tons per sq uare kilometer and per calendar year. This represents a denudation rate of 1.6 +/- 0.6 mm per year, illustrating that mechanical erosion by the Jura g lacier is more intensive than other processes of erosion. (C) 2001 Universi ty of Washington.