Tomtor, the world's largest Sc-REE-Y-Nb-deposit
Kravchenko, S. M.
The Tomtor Massif, which is exposed over an area of more than 250 km 2, belongs to the class of giant carbonatite-nepheline syenite massifs within the alkaline ultramafic association. The spatial restriction of the Tomtor Massif to a junction zone between mantle convective cells led us to suggest the existence of a giant longlived mantle plume. Such plume could bring mantle matter rich in different trace elements related to different metasomatic processes at different depths. The uniqueness of the Tomtor Sc-REE-Y-Nb deposit, which jointly contains both Nb and REE ore mineralisations, can be explained by the genetic relation of the complex to a K-Ca parent mantle magma.