The total global emission of CO2 from soils is recognized as one of largest fluxes in the global carbon cycle and changes in the approach of reclamation of quarries could have a large effect on the concentration of CO2 in the atmosphere and environmental sustainability of ecosystem. CO2 production and sequestration are underestimated for mining areas of Russian North-West. Therefore, investigation of soil organic matter content and quality was conducted on examples of reclaimed postmine lands of Russian North-West. Long-term monitoring data on soil restoration on reclaimed dumps of open quarries in the Kingisepp area of phosphorite mining are discussed. An application of C-13 NMR spectroscopy for investigation of humic substances has revealed very low levels of compositional variability within the soil age. High alifaticity rate has been considered to be indicative of a higher availability of soil organic matter to mineralization.