The Biraya Fe-REE deposit is located in the northern part of the Irkutsk district, Siberia. We are currently studying, along with Dr Pavel M. Kartashov (RAS), a thin, 5-6 cm, carbonatite vein in the deposit. The vein is mineralogically complex – so far more than 30 species have been identified – and records a multistage history of magmatic and hydrothermal events. We can distinguish at least three hydrothermal stage marked by different proportions of F, CO2, SO4, PO4 and Pb in the fluids. Remarkably the history of the vein matches that in some major carbonatite bodies, such as the Palabora Complex, South Africa, and the Khibina massif, Russia.
Mineralogical delights include cordylite-(Ce), daquingshanite-(Ce), törnebohmite-(Ce) and an as yet unidentified REE-carbonate, all with their own petrogenetic story to tell.