Temporal variation of chemical and mechanical weathering in NE Iceland: Evaluation of a steady-state model of erosion

摘要: Abstract This study critically assesses the temporal sensitivity of steady-state model erosion that has been applied to chemical and mechanical weathering studies volcanic islands continents, using only one sample from each catchment. The assumes a geochemical mass balance between initially unweathered rock drainage basin dissolved solid loads river. Chemical composition 178 samples suspended inorganic river constituents, collected in 1998–2002, were studied five basaltic catchments NE Iceland. Hydrological Service Iceland monitored discharge total matter concentration (SIM) glacial rivers for ~ four decades, making it possible compare modelled measured SIM fluxes. Concentration grain size increased with discharge. As proportion clay particles increased, concentrations insoluble elements soluble decreased. highest altered glass was particles. ratio used along data on rocks (high-Mg basalts, tholeiites, rhyolites) calculate pristine original catchment rocks. calculated rhyolite proportions nicely area-weighted average proportions, geological maps these catchments. bedrock model, together constituents Seasonal changes constituent resulted too low SIMmod at high (and discharge). Samples annual load yielded close ones. According had specific denudation rates 1.3–3.0 kg/m2/yr whereas 0.8–3.5 kg/m2/yr which are among Earth. validates use estimate scale when riverine represents over mean hydrological year.