Measurement of Cl⁻ : Br⁻ Ratios in the Porewater of Clay-Rich Rocks—A Comparison of the Crush-and-Leach and the Paper-Absorption Methods

Figure 10

Relationship between air-entry pressure and the difference in Cl⁻ : Br⁻ ratios (Cl⁻ : Br⁻) measured by the crush-and-leach versus the paper-absorption method for the Opalinus Clay (circles) and the Michigan Basin (squares). The error bars represent the range of air-entry pressures reported by Intera [37] for Ordovician shales in the Michigan Basin and by Marschall et al. [38] for the Opalinus Clay.