Séminaire ISTeP - Tatsuhiko Kawamoto

(Kyoto Univ.)

Importance of being salty: Salinity of fluid inclusions in subduction channels and mantle wedges

Saline fluids can effectively transport large-ion-lithophile elements such as Pb, Rb, and Sr. The salinity of fluid inclusions ranges from 3.1 to 5.1 wt% NaCl in mantle peridotites (Luzon, NE Japan, Papua New Guniea) and from 4.3 to 5 wt% in quartz-bearing jadeite-rich rocks of serpentine mélanges (SW Japan, Dominican Republic). These data have values similar to or slightly greater than the value of salinity of seawater (3.5 wt%). Seawater recycling in subduction zones likely occurs without much chemical fractionation with respect to the salinity.

07/10/2016 à 12h30, Salle Fourcade