This locality belongs to a small number of thorianite deposits called the "Groupe d'Ambonaivo" by Behier (1960), situated in the southeastern part of Madagascar. The thorianite mine named Ambonaivo is located about 9 km NE of Belafa. Besaire (1966), who calls it "Amboanaivo", groups the locality under the heading "Zone de Belafa".
References:
- Behier, J. (1960): Contribution á la mineralogie de Madagascar. Annales Géologiques de Madagascar XXIX, Tananarive.
- Besaire, H.(1966): Gites mineraux de Madagascar. Ann. Geo. Mad XXXIV, Tananarive