[en] Earlier unknown chlorite metasomatites and veinlets with elevated (about 1 kg/t) and high (up to 5 kg/t) concentrations of yttrium and rare earth elements were revealed in Strel'tsovskij uranium ore region and studied. Besides chlorite they include xenotime, monazite, rare-earth-containing apatite, bastnaesite, zircon, fluorite, quartz, calcite and hematite. Vienlets are deposited by alkaline (pH ∼ 9) hydrothermal solutions with carbon dioxide under pressure of not less than 0.5 kbar, 310-330 deg C temperature and redox potential close to -0.7 V. Spatial discreteness of different-age mineral associations of the region, the absence of noticeable concentrations of yttrium and rare earths in uranium ores enable to consider chlorite veinlets and metasomatites as independent mineralization. refs., 2 figs., 3 tabs