Publication | Closed Access
Chromium basalts - Experimental determination of redox states and partitioning among synthetic silicate phases
124
Citations
0
References
1976
Year
Unknown Venue
Rare Earth MineralEngineeringSynthetic Silicate PhasesChemistryForsterite-anorthite-diopside SystemsMineral-fluid InteractionChromium BasaltsSilicate CompositionsHigh Temperature GeochemistryMaterials ScienceInorganic ChemistryGeologyCrystallographyLunar Basaltic LiquidsRedox StatesGeochemistryExperimental PetrologyPetrologyMineral Geochemistry
Experiments were performed on silicate compositions in the forsterite-anorthite-silica and forsterite-anorthite-diopside systems to determine the relative amounts of Cr(II), Cr(III), and Cr(VI) over a wide range of oxygen partial pressures from 10 to the -10th to 1 atm at 1500 and 1550 C. Redox states were measured by visible absorption spectroscopy and electron paramagnetic resonance spectroscopy and titration. It was found that Cr is present almost exclusively as Cr(III) in terrestrial basaltic liquids and as a mixture of Cr(III) and Cr(II) in lunar basaltic liquids.