Fig. 2: Stream-water chemistry across the erosion rate gradient.
From: Co-variation of silicate, carbonate and sulfide weathering drives CO2 release with erosion
a–e, Concentrations of calcium and sulfate (a), silica and sodium (b), magnesium and potassium (c), cations from carbonate weathering (d) and cations from silicate weathering and sulfate from sulfide oxidation (e). f, Fraction of cation charge contributed from carbonate weathering and fraction of cation charge balanced by sulfate. All results are plotted against the catchment-averaged steepness index (lower x axis) and inferred erosion rates (upper x axis). Symbols mark dominant lithology (see Fig. 1). Error bars are equivalent to a 95% confidence interval. Samples with anomalously high sulfate concentrations are marked as darker points.
