Mantle-derived Fluids in
Oded Navon, Ian D.
Hutcheon, George R. Rossman, Gerald J. Wasserburg
Division of Geological and Planetary Sciences
California Institute of Technology, Pasadena, CA 91125
Micro-inclusions in diamonds from Zire and Botswana differ in
composition from the more common large inclusions of the peridotitic or
eclogitic assemblages. These sub-micrometre inclusions resemble
potassic magmas in their composition, but are enriched in H2O,
CO32-, and K2O
and depleted in MgO. This composition
represents a volatile-rich fluid or melt from the upper mantle, which
was trapped in the diamonds as they grew.
Coated diamond from Zaire