Solute fluxes from a glacier-covered alpine catchment are partitioned into components derived from sea-salt, acid aerosol, dissolution of atmospheric 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 amounts of solute. Chemical denudation constitutes <1.5% of solid denudation but is significantly higher than the continental average. CO2 drawdown by weathering reactions varies directly with discharge and suspended-sediment load and inversely with meltwater p(CO2). If it is generally true that flushing rates control CO2 drawdown in glacier-covered catchments, then glacially driven chemical weathering could be a significant factor in carbon cycling and climate change on glacial-interglacial time scales.
- Geological Society of America