Ice-VII inclusions in Diamonds: Evidence for Aqueous Fluid in Earth’s Deep Mantle
Water-rich regions in Earth’s deeper mantle are suspected to play a key role in the global water budget and the mobility of heat-generating elements. We show that ice-VII occurs as inclusions in natural diamond and serves as an indicator for such water-rich regions. Ice-VII, the residue of aqueous fluid present during growth of diamond, crystallizes upon ascent of the host diamonds but remains at pressures as high as 24 gigapascals; it is now recognized as a mineral by the International Mineralogical Association. In particular, ice-VII in diamonds points toward fluid-rich locations in the upper transition zone and around the 660-kilometer boundary.
Prakapenka, V. B.,
Rossman, G. R.,
Shen, A. H.,
Ice-VII inclusions in Diamonds: Evidence for Aqueous Fluid in Earth’s Deep Mantle.