Khaldzan Buragtag massif, Altai Mts, Hovd Aimag (Khovd Aimag), Mongolia

Complex tantalum-niobium-zirconium-rare earth mineralization spatially and genetically associated with a multiple phase intrusion of alkaline granitoids.
The massif is formed by two outcrops: Concentric Southern (with top on Khaldzan Buregtei Ula Mt) and garpolite like Northern one (with top on Ulyn Khuren Mt). In shape massif resemble "!". Southern outcrop includind Khaldzan Buregtei Ta-Nb-Zr-REE deposit in agpaitic alcaline granites of V&VII intrusive phases. Northern outcrop composed mainly from nordmarkites of I intrusive phase and including Tsakhirin Khuduk Y-Zr-Nb deposit in exocontact metasomatic zone.

References:
- Kartashov P.M., Voloshin A.V., Pakhomovsky Ya.A. (1992) On plumbopyrochlore from Western Mongólia. Doklady Akademii Nauk SSSR, 322, p. 1137-1140. (in Rus.).
- Kovalenko V.I., Tsaryeva G.M., Goreglyad A.V., Yarmolyuk V.V., Troitsky V.A., Hervig R.L., Farmer, G.L., (1995) The peralkaline granite-related Khaldzan-Buregtey rare metal (Zr, Nb, REE) deposit, western Mongolia - ECONOMIC GEOLOGY, v. 90, p. 530–547.