Short description of important scientific result: Novel techniques for measuring the wetting contact angle of clay surfaces, modes for preparing a clay specimens and statistical processing of measurements have been worked out. The hysteresis peculiarities of wetting on clay specimens are refined for the various mineral composition and pore space structure. A digital database of the contact angle for 100 types of clay surfaces and their analogues has been compiled. Model experiments were carried out to detect the effect of carbophilic chemolithotrophic biofilm on clay particles. Biocementation during the propagation of a psychrophilic carbophilic chemolithotrophic biofilm was originally simulated in a deterministic way considering the conservation of an organic matter part.