Karly Z. Geochemistry REE-U-Th ore occurrences in the western part of the Ukrainian Shield

Dissertation is devoted to the solution of actual problems of ore-bearing in Precambrian complexes of Ukrainian Shield. It was established that the primary source of REE-U-Th mineralization were primary sedimentary Proterozoic and Archean rocks which have been enriched in uranium, thorium, rare earths, molybdenum and bismuth. Aplite-pegmatoid granitoids have been form during granitization processes that formed Si-K metasomatites are relate to these granitites. Similar values of primary 87Sr/86Sr of these rocks indicate their genetic relation. The mineral-concentrators of REE, U and Th in Si-K metasomatites are apatite, zircon, monazite, thorite, xenotime, uraninite, pitchblende, coffinite, uranium black, autunite and schoepite. In the western part of the Ukrainian Shield ore-bearing aplite-pegmatoid granites and related REE-U-Th metasomatites Si-K association formed during age range in 2080-1980 Ma. For the first time in the Precambrian rocks of the Ukrainian Shield the epigenetic uranium ore mineralization is determined in the crack zones of aplite-pegmatoid granitoids, extending over 330 m depth. Uranium is deposit as lowtemperature oxides and hydroxides in the cracks filled with hydromica-carbonate aggregates, iron oxides, manganese oxides. Coronadite is rare mineral that rarely mentioned in Precambrian rocks of the Ukrainian Shield, is detect as well. Schoepite is mineral that was formed due to the decay of pitchblende and uranium oxide-hydroxide mineral, has been detect for the first time.