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

About 75% of the terrestrial land surface of our planet is covered by sedimentary rocks, butabout 80% of this area is composed of fine-grained shale or carbonate lithologies. When alsoincluding mafic rocks, a large global terrestrial area is inaccessible to the in situ 10Becosmogenic nuclide method, as it requires the presence of sand-sized quartz minerals. Hence,in order to quantitatively constrain the erosion and weathering rates of these areas andto derive globally meaningful solid and solute fluxes, new methods are required.A recently developed tracer to study Earth surface erosion and weathering is themeteoric 10Be/9Be ratio1, from which meteoric denudation rates (Dmet) can becalculated. Meteoric cosmogenic 10Be is deposited from the atmosphere onto Earthsurface, where it is adsorbed to any fine-grained solid material or, depending on pH,is present in the dissolved form, whereas stable 9Be is a trace metal released byweathering. We show the broad versatility of this new approach by its application to twogeomorphically contrasting settings. In the transport-limited setting of the middle Europeanuplands of the Slavkov Forest, Czech Republic, small (<1 km2) neighboring catchments ofsimilar size, climate, slope, and vegetation are underlain by mafic (amphibolite), ultramafic(serpentinite), and felsic (granitic) rocks. Quartz is present in all these catchments in thebedrock or in quartz veins, making a comparison with in situ cosmogenic-deriveddenudation rates (Dinsitu)possible. Due to acid rain deposition in the 20th century,pH values of stream waters vary from acidic to alkaline, depending on the acidbuffering capability of individual lithologies. By balancing the depositional 10Be fluxwith the exported dissolved and particulate 10Be flux, we show that steady stateattained before industrial soil acidification in all three catchments, suggesting anegligible loss of dissolved Be due to acidic conditions. This is supported by the overallagreement of Dmet with Dinsituin the studied catchments that range from 0.04 to 0.08mm/yr2. In the supply-limited setting of the high and steep mountainous island of Taiwan, amongthe World´s highest denudation rates prevail due to high uplift rates and frequent typhoonattacks. We studied Taiwan´s longest river, the Zhuoshui River (3000 km2), whereheadwaters are dominated by slate with Dmet ranging from 4-8 mm/yr, agreeing withpublished long-term exhumation rates. In the mid-lower sandstone-dominated reaches, lowerDmet agree with published Dinsitu, being in the order of 1-2 mm/yr. We suggest that agradual dilution of the sediment contribution from the rapidly-eroding slate in the headwaterswith sediment from slowly-eroding sandstone reaches is responsible for the downstreamdecrease in Dmet. In both these settings representing geomorphic end members, denudation rates calculatedfrom the 10Be/9Be ratio of the particle-bound Be are very similar to independent denudationrate estimates and prevailing lithological and geomorphological conditions. This agreementevidences the versatile potential of the meteoric 10Be/9Be proxy to quantify Earth surfaceprocesses in a wide range of landscapes, lithologies, hydrological conditions and sedimenttransport processes. 1 von Blanckenburg, F., et al. EPSL, 2012. 2 Dannhaus, N. et al., GCA, 2018. [ABSTRACT FROM AUTHOR]