High pressure, high temperature studies of methane-water mixtures

Recently, experiments conducted on methane at high pressures and temperatures have produced evidence to suggest that abiogenic processes in the upper mantle have the potential to yield longer-chain hydrocarbons, including petroleum spectrum hydrocarbons. We have conducted in-situ Raman scattering measurements in the laser-heated diamond-anvil cell on methane-water mixtures to characterize how an oxidizing agent, water, would alter methane-methane interactions from those observed in the pure phase. Results from laser heating showed diamond and hydrogen formation and complex hydrocarbon production in the presence of water, suggesting that abiogenic reactions of methane to form heavy hydrocarbons can occur in hydrous environments within the Earth.