Contributions of visible and invisible pores to reactive transport in dolomite

Recent technical advances have demonstrated the importance of pore-scale geochemical processes for governing Earth’s evolution. However, the contribution of pores at different scales to overall geochemical reactions remains poorly understood. Here, we integrate multiscale characterisation and reactive transport modelling to study the contribution of pore-scale geochemical processes to the hydrogeochemical evolution of dolomite rock samples during CO2-driven dissolution experiments. Our results demonstrate that approximately half of the total pore volume is invisible at the scale of commonly used imaging techniques. Comparison of pre- and post-experimental analyses demonstrate that porosity-increasing, CO2-driven dissolution processes preferentially occur in pores 600 nm–5 μm in size, but pores