Azov and Yastrubetskyy massifs (Azov and Volyn megablocks Ukrainian shield, respectively) are typical hipersolvus syenites, anorthoclase-perthite contains 55-75% of albite component and the femic minerals of high and limit ferruginous composition (hedenbergite, ferohastingsite, fayalite, annite) are characterized by low values of the oxidation coefficient. These objects are petrologically identical. The goal of the work is: a) to compare the mineral composition, conditions of formation of geological objects containing REE, Y, Zr of the Azov and Volyn megabloks; b) to determine the cause of the absence of industrial REE mineralization of the Yastrubetskyy zirconium ore occurrence; c) to impose conditions on the accumulation of REE and Y on the unique Azov deposit. For research we used the following methods: X-ray diffraction analysis, thermobarogeochemical analysis (methods for the study of inclusions), electron microprobe analysis, luminescent analysis (PL, RL), IR spectroscopic analysis, ICP MS determination of elements. The results showed that the major minerals-concentrators of REE (zircon and britholite) of Azov and Yastrubetskyy syenite massifs have magmatic origin. In the Azov deposit britholite crystallized simultaneously with zircon or before zircon. This feature of crystallization of these minerals is explained compatible and separate accumulation in the deposit. High PT parameters (> 1030°C, > (450-520) MPa) took part in formation of CO2 fluids streams of the Azov deposit. Postmagmatic fluids are caused metasomatic replacement of britholite, in resulting it was redistribution of contents REE and Y: the contents of light REE increased in monazite and heavy REE and Y - in bastnaesite and secondary britholite. Influence of CO2 solution siderite at the Azov deposit, and is formed carbonate-fluorite veins at the Yastrubetskyy deposit . In Yastrubetskyy deposit the absence of britholite is caused probably very low content of phosphorus in magmatic melt, resulting in REE have been concentrated in fluorite. A small content of yttrium and rare earths in fluorite mineralization occurs within and outside of the massif. At present it is not the subject of commercial recovery yttrium and rare earth elements.
2007 to 2011