Speciation of reduced C-O-H volatiles in coexisting fluids and silicate melts determined in-situ to similar to 1.4 GPa and 800 degrees C

The structure of silicate melts in the system Na2O center dot 4SiO(2) saturated with reduced C-O-H volatile components and of coexisting silicate-saturated C-O-H solutions has been determined in a hydrothermal diamond anvil cell (HDAC) by using confocal microRaman and FTIR spectroscopy as structural probes. The experiments were conducted in-situ with the melt and fluid at high temperature (up to 800 degrees C) and pressure (up to 1435 MPa). Redox conditions in the HDAC were controlled with the reaction, Mo + H2O = MoO2 + H-2, which is slightly more reducing than the Fe + H2O = FeO + H-2 buffer at 800 degrees C and less.