Magmatic vs. hydrothermal - origin of parisite-hosted REE mineralization at Nam Xe, Vietnam.


Magmatic vs. hydrothermal - origin of parisite-hosted REE mineralization at Nam Xe, Vietnam.

Heinig, T.; Möckel, R.; Krause, J.; Gutzmer, J.; Phan Quang, V.; Burisch, M.

The REE mineralization of Nam Xe, Vietnam, provides important new insights into paragenically complex carbonatite-related REE mineral formation associated with the transition from magmatic to hydrothermal conditions. Carbonatite dykes at Nam Xe comprise of calcite, ankerite and barite; these are crosscut by younger veins consisting of rare earth fluorcarbonates, fine-grained barytocelestine and calcite. The dominant rare earth fluorcarbonate is parisite [(REE)2Ca(CO3)3F2] with only minor bastnäsite and synchysite. Petrographic observations reveal that REE-mineralization is polystadial. Early bastnäsite associated with the magmatic stage is subsequently replaced by parasite in the presence of a Ca-CO3-rich carbothermal fluid. Parisite is then again overprinted by a Sr- rich hydrothermal fluid resulting in the formation of REE-enriched parisite and calcite.

Keywords: Rare earth fluorcarbonates; parisite; bastnäsite; carbonatite

  • Lecture (Conference)
    15th Biennial Meeting of the Society for Geology Applied to Mineral Deposits, 27.-30.08.2019, Glasgow, Scotland

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Publ.-Id: 28959