P-T-conditions and fluid compositions were estimated for mineral parageneses from inclusions in diamonds, diamond-bearing and diamond-free xenoliths using a garnet-clinopyroxene-silica oxygen barometer (Simakov, 2006). These data indicate that the upper mantle is zoned, with relatively oxidized lithosphere and reduced asthenosphere. Calculations in the system C-O-H indicate that eclogite inclusions within diamonds and xenoliths have formed mainly in equilibrium with water-rich fluids.
1. Simakov S.K. 2006. Contrib Mineral Petrol .151: 282-296.