Cryogenesis of granites and gneisses in South Yakutia

Based on field and laboratory studies of the rock massifs in South Yakutia using remote earth sensing technologies, methods of scanning electron microscopy, X-ray 3D tomography, lithological-mineralogical and optical-petrographic studies, quantitative data on the intensity of cryogenesis of granites and gneisses in this area were obtained. A 16%-20% increase in the fracturing of rocks at the near-surface part of the rock massif was shown to have occurred over a 10-year period; during this time, vertical landforms, represented by granites and gneisses, retreated at a rate of 3 mm per year. However, no variations in the chemical and mineral composition of these rock types were identified over the study period. When alternate freezing and thawing (cryogenesis) soils undergo diverse metamorphoses resulting in changes of soil properties. The establishment of mechanisms occurring at cryogenesis in soils at the scale of chemical compounds and minerals grains has a universal character and can be applied to address a wide range of engineering-geological problems.image