The flotation of magmatic sulfides transfers Cu-Au from magmas to seafloor massive sulfide deposits

Copper and gold-rich seafloor massive sulfide deposits formed in intra-oceanic subduction settings are typically associated with hydrous and oxidized magmas, but processes leading to their formation remain controversial. Sulfide-bubble interaction has been suggested to play an important role in metal transfer from magmas to seawater-derived hydrothermal fluids. Here we use textural observations of magmatic sulfides, geochemical numerical models of chalcophile element concentrations, and numerical models of magmatic sulfide growth within a mafic to felsic submarine magmatic suite (Fatu Kapa, SW Pacific) associated with copper-gold-rich seafloor massive sulfide deposits. We demonstrate that concomitant sulfide and aqueous fluid formation at the andesitic stage results in floating sulfide-bubble compound drops in magmas, which play a crucial role in the transfer of copper and gold toward the surface. We emphasize that late sulfide saturation in copper-gold-rich intra-oceanic subduction-derived felsic magmas favors upward sulfide transfer via flotation. The flotation of sulfide-bubble compounds in magmas plays an important role in forming Cu-Au hydrothermal seafloor ore deposits, according to petrographic observations, geochemical and physical modeling.

Full Text

FilePagesSizeAccess
Publisher's official version
164 Mo
Transparent Peer Review file
30176 Ko
Supplementary Information
413 Mo
How to cite
Jeanvoine Aurelien, Park Jung-Woo, Pelleter Ewan, Bezos Antoine, Chazot Gilles, Hwang Jiwon, Fouquet Yves (2024). The flotation of magmatic sulfides transfers Cu-Au from magmas to seafloor massive sulfide deposits. Communications Earth & Environment. 5 (1). 462 (16p.). https://doi.org/10.1038/s43247-024-01571-9, https://archimer.ifremer.fr/doc/00905/101737/

Copy this text