[en] Chlorite-orthoclase uranium-bearing metasomatites, particularities of their geological location and mineral-petrographical composition, their zonality are studied. A detailed characteristic of the main rockforming metasomatite minerals - hematite, chlorite, potassium feldspar and calcite is given. For studying the NbR, X-ray and chemical analyses and electron-microscopic investigations are used. Using the homogenization method for gas-liquid inclusions in calcite it is found that solutions are low-temperature ones with a high carbonic acid content. It is shown that the described rocks are typical hydrothermal metasomatites having nothing in general with the crusts of weathering. At the same time these rocks differ in the main from the known metasomatites of low-temperature formations