The earth is a hugh and complex chemical reactor. From its atmosphere and surface to crust and mantle down to its inner core, phases adapt to changing physical and chemical conditions, which could be changes in pressure, temperature, or chemical potentials. Accordingly new phase assemblages form and individual phases adjust their composition.
In the geosciences natural rocks, minerals, soils, melts, glasses, fluids, and gases are sampled and the question usually arises, where and at what conditions have they formed and how are they linked to large and small scale geological processes. These processes might be large scale such as mantle convection, subduction of oceanic crust, collision of continents, or of regional extend like magmatism, metamorphism, metasomatism or just local like formation of ore deposits, shallow fluid, and weathering.

Content of PhysChemGeo

This site intends to provide information how geological systems can be treated and addresses students and all interested geochemists. The content of this site will not be complete, it can not replace textbooks, however, it will provide derivations which are often hard to find. Moreover the content of this site will grow over time.

• introduction to chemical thermodynamics
• treatment of solid, fluids, and melts at elevated pressures and temperatures
• mixing properties of complex phases
• providing code and tools to perform thermodynamic calculations using Mathematica
• providing and communicating thermodynamic standard properties


• fluids and fugacities