The effect of lithology on the relationship between denudation rate and chemical weathering pathways – evidence from the eastern Tibetan Plateau

Abstract. The denudation of rocks in mountain belts exposes a range fresh minerals to the surface Earth that are chemically weathered by acidic and oxygenated fluids. impact resulting coupling between weathering rates fundamentally depends on types weathering. Whereas silicate sequesters CO2, combination sulfide oxidation carbonate dissolution emits CO2 atmosphere. Here, we combine concentrations dissolved major elements stream waters with 10Be basin-wide from 35 small catchments eastern Tibet elucidate importance lithology modulating relationships rate, chemical pathways, consumption or release. Our span 3 orders magnitude rate low-grade flysch, high-grade metapelites, granitoid rocks. For each stream, estimate solutes sourced weathering, dissolution, using mixing model. We find for all lithologies, cation largely independent but solute carbonates and, where present, sulfides increase increasing rate. With rates, may therefore shift consuming releasing both (meta)sedimentary lithologies. given report solid inferred fluxes underlain rock 2–10 times higher compared containing even though climatic topographic parameters do not vary systematically these catchments. Thus, varying proportions exposed igneous during orogenesis could lead changes sequestration release