Aqueous fluid speciation calculations with Thermolab for modelling open system processes

Aqueous fluids play an essential role in the distribution of chemical elements in the lithosphere. Together with the biosphere, hydrosphere and atmosphere they form an important part of the geochemical cycles in the Earth System. Calculating the chemical composition of aqueous fluids in equilibrium with minerals involving solid solutions is a prerequisite for predictive modelling of open system processes that occur at depth in the Earth. Here it is shown how to do such calculations with Thermolab (Vrijmoed & Podladchikov, 2022). The focus is on the technical details related to Thermolab where efforts were made to facilitate education and clarification of widely known concepts in aqueous speciation calculations. Technical advancements are proposed and compared with classical methods.
Vrijmoed, J. C., & Podladchikov, Y. Y. (2022). Thermolab: A thermodynamics laboratory for nonlinear transport processes in open systems. Geochemistry, Geophysics, Geosystems, 23, e2021GC010303. https://doi.org/10.1029/2021GC010303