Tiny but timely: Crystal surface reactivity constraints on diagenesis

Quantitative variability of diagenetic alteration is a major challenge for the development of predictive concepts. Here, we focus on the nano- and microscopic variability of crystal surface reactivity as a major constraint to fluid-solid reactions. While density and distribution of defect structures play a critical role, additional important impact is provided by the interaction of surfaces with nanoparticles and colloids during precipitation reactions. Quantitative data are available from multiple surface-sensitive methods that provide mechanistic insight via reaction rate maps and rate spectra and challenge the prevailing view that crystal dissolution is simply the inverse process of continuous crystal growth at crystal dislocations, e.g., during secondary porosity formation. Mechanistic insight is available from kinetic Monte Carlo methods, e.g., about inherited reactivity. The upscaling of such simulation results to the pore scale is a challenging task that requieres novel numerical approaches. Additionally to heterogeneities of the fluid flow field, reactive transport modeling approaches need to address ultimately the variability in surface reactivity in order to provide improved predictability.