Main genetic models of the formation of ultra-rich rare metal ores of the Tomtor deposit (Yakutia) are compared on the basis of their structural-textural features, mineral composition, and geologic setting: 1) reducing epigenesis of laterite weathering crusts of carbonatites and 2) redeposition of weathering products of carbonatites. It is shown that the unique features of the Tomtor deposit are explained by more complex (compared with other deposits of weathering crusts of carbonatites) evolution, which is expressed in two consecutive stages of supergenesis: laterite weathering and reducing epigenesis and their total ore-concentrating efects. The searching-forecast criteria for ores of the Tomtor type are suggested on the basis of epigenetic model of their formation.

Figures 10. Table 1. References 16.

Key words: Tomtor deposit, unique rare-metal ores, genesis, pyrochlore, monazite, reducing epigenesis, residual lacustrine placer.

A.V. Lapin, Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare Elements, ul. Veresaeva 15, Moscow, 121357 Russia; lapin@imgre.ru

A.V. Tolstov, Research Geological Enterprise AK «ALROSA», Chernyshevskoe shosse 16, Mirny, Republic of Sakha (Yakutia), 678170 Russia

I.M. Kulikova, Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare Elements, ul. Veresaeva 15, Moscow, 121357 Russia

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