This study, which has been funded by the German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV, grant agreement No. 0325217), the European Union's Horizon 2020 Research and Innovation Programme (grant agreement No. 850626) and the Helmholtz Association in the framework of the national German geoscientific large-scale infrastructure project GeoLaB (https://www.geolab.kit.edu/english/index.php), reports on newly acquired density data of synthetic aqueous solutions of sodium chloride (NaCl) and calcium chloride (CaCl₂), which have been prepared in a single salt and mixed form. The solutions span a wide range of concentrations and mixing ratios that are geothermally encountered. The data presented here cover temperatures between 293 K and 353 K at ambient pressure.

The measured data were obtained at the GFZ German Research Centre for Geosciences.