Mineralogy and Geochemistry

Minerals precipitated in the rock matrix during diagenesis or hydrothermal alteration, as well as fracture infilling minerals, are archives of past fluid-flow events. Based on the textures, the chemical and isotopic compositions of rocks and individual minerals, we reconstruct the sequence of events and infer the fluid sources.

Carbonate and sulphate minerals frequently are the primary controls on the pore-water compositions. In clay-bearing rocks, clay minerals also affect pore-water chemistry via cation-exchange equilibria. We identify and characterise these minerals as a basis for thermodynamic models that reconstruct the pore-water composition.