Data for: Control of riverine Mg isotopes by cation exchange in extremely-high-erosion catchments: Evidence from the Three Rivers, southeastern Tibetan Plateau

Raw data for all figures in the manuscript by Yang Xu et al. to be published by Geochimica et Cosmochimica Acta as "Control of riverine Mg isotopes by cation exchange in extremely-high-erosion catchments: Evidence from the Three Rivers, southeastern Tibetan Plateau".