The Genesis of Blue Diamonds

Lucille Daver , Helene Bureau (1) , Eloise Gaillou (2) , E. Boulard (1) , Benoît Baptiste (3) , Oulfa P Belhadj (4) , Nicolas Guignot (5) , Eddy Foy (6) , Pierre Cartigny (7) , Daniele L. Pinti (8)

1 IMPMC - Institut de minéralogie et de physique des milieux condensés
2 Mines Paris - PSL (École nationale supérieure des mines de Paris)
3 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
4 CRC - Centre de Recherche sur la Conservation
5 SSOLEIL - Synchrotron SOLEIL
6 LAPA - UMR 3685 - Laboratoire Archéomatériaux et Prévision de l'Altération
7 IPGP - Institut de Physique du Globe de Paris
8 GEOTOP - Centre de recherche sur la dynamique du système Terre

Forming fluid: Primary and secondary inclusions may be the witness of a H 0-C parent fluid 2 graphite Mineral assemblage: Inclusion of Ilmenite : Eclogitic paragenesis at lithospheric depth Inclusion of walstromite (retrogressed Ca-Perovskite (CaTiO3); >9 Gpa): Sub-lithospheric depth Boron: inherited from sea water through the subduction zone : H 0 + C + boron, available in the 2 organic lithosphere after slab dehydration: Data suggest a deep recycling of marine fluids that may be the the parents of blue diamonds We suggest that blue diamonds are not exclusively ultra-deep and may form at any depth in the mantle, from lithosphere (>150km) down to the lower mantle (~750 km), in subduction-related B-CH O-rich fluids.

Domaines: Physique Générale [physics.gen-ph]

Lucille Daver, Helene Bureau, Eloise Gaillou, E. Boulard, Benoît Baptiste, et al.. The Genesis of Blue Diamonds. 2019 Diamond Conference, Jul 2019, Warwick, United Kingdom. ⟨hal-02506335⟩