Fig. 3: Link between sulfuric acid, weathering and pH.
From: Co-variation of silicate, carbonate and sulfide weathering drives CO2 release with erosion
a, Co-variation of cation concentrations with sulfate. b, Predicted maximum pH in the weathering zone (pHeq) against catchment-averaged steepness index (lower x axis) and inferred erosion rates (upper x axis). c, Predicted pH for a carbonate-buffered solution after addition of sulfuric acid (\({\mathrm{pH}}_{{\rm{SO}}_4}\)) against the equilibrium pH. The solid line shows regression with 95% confidence bands; the dotted lines show initial pH before addition of sulfuric acid. 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.
