Barium concentration and stable isotope ratio measurements of the dissolved and adsorbed phases from laboratory batch experiments and Himalayan river samples from 2015-2016

This dataset contains barium concentration and stable isotope ratio measurements of the adsorbed and dissolved phases associated with batch laboratory adsorption-desorption reactions using common environmental mineral adsorbents (clay minerals: kaolinite & montmorillonite, iron-oxyhydroxides: goethite and ferrihydrite) and surface waters (river water, groundwater and seawater). The experiments systematically changed several variables (reaction duration, adsorbent concentration, water type and the pre-experiment adsorbent cleaning procedure). Barium concentration and stable isotope ratio measurements of the adsorbed and dissolved phases from two Himalayan rivers (Saptakoshi River and Sunkoshi River) are also provided.

All experiments and analyses were performed in the Department of Earth Sciences at the University of Cambridge. Barium concentrations were determined in two independent ways: 1. Inductively coupled plasma optical emission spectroscopy (ICP-OES) on an Agilent 5100. 2. Isotope dilution via thermal ionisation mass spectrometer (TIMS) on a Thermo Fischer Scientific Triton Plus. Barium isotope ratios were measured via TIMS on a Thermo Fischer Scientific Triton Plus. Barium was separated from other elements via column elution chromatography (AG50W-X8 resin). A double-spike procedure was used to correct for mass-dependent isotope fractionation. The NIST-3104a and NBS-127 standards were used to quantify the uncertainty associated with isotope ratio measurements (0.03 ‰). Field samples of river water and sediment were collected from the surface of the water column from stationary sampling locations (Chatara and Khurkot) as part of the Perturbations of Earth Surface Processes by Large Earthquakes (PRESSurE) Project: https://www.gfz-potsdam.de/en/section/geomorphology/projects/pressure/. The water and sediment samples were immediately separated following collection via filtration through 0.22-micrometre polyethersulfone (PES) membrane filters. Further information on the field samples can be found at: https://doi.org/10.5880/fidgeo.2024.008. The desorption of barium from the surfaces of sediment and the laboratory adsorbents was achieved using repeated additions of 1.0 mol/L ammonium chloride (Puratronic™, 99.999% (metals basis), Thermo Scientific Chemicals).