Rare metal mineralization in uncommon scapolite-bearing rocks from Ilmeny Mountains (South Urals)

Korinevsky V. G., Korinevsky E. V., Kotlyarov V.A.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2018. V. 147. N 4. P. 52-68

https://doi.org/10.30695/zrmo/2018.1474.04

Full text is available on eLIBRARY.RU

Language: Russian

Abstract

Unusual magmatic rocks: scapolite-bearing gabbro, granites, mica rocks (glimmerites), and quartz-scapolite pegmatites have been found in the Ilmeny Mountains at the South Urals. They occur as cross-cutting dyke bodies in the block of calcite-dolomite carbonatites. Quartz-scapolite pegmatite contains disseminated small zonal grains of titanium-uranium-niobates of pyrochlore and betafite groups, with content of UO2 up to 13—27 %. This rock contains also small amount of ilmenorutile segregations with up to 21.8 % Nb2O5 and 20.5 % Ta2O5, as well as allanite-(Ce) with 15 % REE2O3. There are separate grains of monazite and scheelite, too. Up to the date, the similar mineralization was described only in granite pegmatites and carbonatites; in scapolite-bearing rocks it is discovered for the first time.

Key words: quartz-scapolite pegmatites, titano-uranium-niobates, pyrochlore, ilmenorutile, allanite, zircon, thorite, the South Urals.