Chris Ballhaus

Redox states of lithospheric and asthenospheric upper mantle

AbstractThe oxidation state of lithospheric upper mantle is heterogeneous on a scale of at least four log units. Oxygen fugacities (

Is the upper mantle metal-saturated?

f_{O_2 }

The generation of oxidized CO2-bearing basaltic melts from reduced CH4-bearing upper mantle sources

) relative to the FMQ buffer using the olivine-orthopyroxene-spinel equilibrium range from about FMQ-3 to FMQ+1. Isolated samples from cratonic Archaean lithosphere may plot as low as FMQ-5. In shallow Proterozoic and Phanerozoic lithosphere, the relative

The partitioning of Fe, Ni, Cu, Pt, and Au between sulfide, metal, and fluid phases: A pilot study

f_{O_2 }

Platinum-group elements in the Merensky Reef: II. Experimental solubilities of platinum and palladium in Fe1−xS from 950 to 450°C under controlled ƒS2 and ƒH2

is predominantly controlled by sliding Fe3+-Fe2+ equilibria. Spinel peridotite xenoliths in continental basalts follow a trend of increasing