Rare Earth Element Resource Potential of Super-Large Deposits in Eastern Fennoscandia

This work has been carried out to assess the rare-earth potential of the main ore minerals of the Lovozero and Khibiny deposits. The loparite and eudialyte deposits are associated with the giant Lovozero intrusion (Eastern Fennoscandia, Kola Peninsula). There are several deposits of apatite-nepheline ores in the Khibiny complex. All these ores take the leading position in the structure of the raw material base of Russia. The highest contents of the sum of rare earth metals (REMs) are typical of loparite ores (the content of Sigma REE in loparites is about 28 wt %), light rare earths sharply dominate over heavy ones (the Ce/Yb ratio is about 78000). The sum of REEs in eudialytes is about 2 wt %. A remarkable feature of eudialyte ores is the high concentration of the heavy REM group (the Ce/Yb ratio is about 14). The apatites of the Khibiny deposits occupy an intermediate position: the Ce/Yb ratio is 680, and the average concentration of the REE sum is 0.9 wt %. The conditions of formation of apatite, loparite, and eudialyte ores are considered.