RATES OF CHEMICAL DENUDATION AND CO2 DRAWDOWN IN A GLACIER-COVERED ALPINE CATCHMENT

Solute fluxes from a glacier-covered alpine catchment are partitioned into components derived from sea salt, acid aerosol, dissolution of at mospheric CO2, and crustal weathering. The bulk of solute is crustally derived. Coupled sulfide oxidation and carbonate dissolution (SO-CD) and carbonation of carbonate minerals generate approximately equal amo unts of solute. Chemical denudation constitutes <1.5% of solid denudat ion but is significantly higher than the continental average. CO2 draw down by weathering reactions varies directly with discharge and suspen ded-sediment load and inversely with meltwater p(CO2). If it is genera lly true that flushing rates control CO2 drawdown in glacier-covered c atchments, then glacially driven chemical weathering could be a signif icant factor in carbon cycling and climate change on glacial-interglac ial time scales.