Measured oxygen fugacities of the Angra dos Reis achondrite as a function of temperature

Measurements of the oxygen fugacity, f(O2), as a function of temperature, T, were made on an interior bulk sample of the cumulate achondrite, Angra dos Reis. Data clustered between the f(O2)-T relationship of the iron-wustite assemblage and 1.2 log atm units above iron-wustite. Interpretation of the data indicates that, throughout most of the cooling history of the meteorite, f(O2) values were defined by equilibria involving iron-bearing species at values close to the f(O2) of the assemblage iron-wustite. Measured f(O2) data are compatible with crystallization and cooling at pressures greater than 50 bars.