Uranium-bearing zeolite-analcime concretions with authi genous loellingite

Zeolite-analcime concrections, mounted in green-coloured molasses of middle Palaeozoic, were studied by X-ray radiometric method. It is established that concrection formator is heliogenious carbonated pellitemorphic material arisen at the cost of aluminium-silicon gels in the process of their dehydration into the sediment diagenesis stage. Uranium, molybdenum, arsenic, zirconium and other metals are scattered in a dispersed way in the pellitemorphic material. They are present in the aqueous solution of liquid inclusions. They can also form smallest extractions of nasturane, uranium black (coffinite), loellingites, pyrite, chalcopyrite, arseno-pyrite, molybdenite and others in the substrate. Loellingite forms tetra and hexabeam triplets. There are xenomorphic extractions and seldom crystals with extended rectangular or hexagonal cross sections in big grains. Its main constituents are arsenic and ferrum. The loellingite presence in the concrections studied testifies to the possibility of its formation not only under the conditions of hydrothermal and metasomatic deposits, but in a wider range of thermodynamic conditions