Ferric Iron Content of Mineral Inclusions in Diamonds from São Luiz: A View into the Lower Mantle
- 17 October 1997
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 278 (5337) , 434-436
- https://doi.org/10.1126/science.278.5337.434
Abstract
Mössbauer spectroscopy on inclusions in diamonds from São Luiz, Brazil, show that (Mg,Fe)O inclusions contain little Fe3+ (Fe3+/ΣFe ≤ 7%), whereas inclusions with pyroxene composition (believed to have been originally in the perovskite structure) and tetragonal almandine-pyrope phase (TAPP) inclusions contain high relative amounts of Fe3+ (Fe3+/ΣFe = 20 to 75%). These observations are consistent with high-pressure experiments on synthetic samples and support the idea that the inclusions originated in the lower mantle. Fe-Mg partitioning data for co-existing (Mg,Fe,Al)(Si,Al)O3 – (Mg,Fe)O pairs also indicate that the phases were in equilibrium at the time of diamond formation in the lower mantle.Keywords
This publication has 14 references indexed in Scilit:
- A new tetragonal silicate mineral occurring as inclusions in lower-mantle diamondsNature, 1997
- The Effect of Alumina on Phase Transformations at the 660-Kilometer Discontinuity from Fe-Mg Partitioning ExperimentsScience, 1996
- Crystal chemistry of iron-containing perovskitesPhase Transitions, 1996
- Lower Mantle Mineral Associations Preserved in DiamondsMineralogical Magazine, 1994
- Partitioning of MgO, FeO, NiO, MnO and Cr2O3 between magnesian silicate perovskite and magnesiowüstite: implications for the origin of inclusions in diamond and the composition of the lower mantleEarth and Planetary Science Letters, 1992
- X-ray microanalysis of high-pressure/high-temperature phases synthesized from natural olivine in a diamond-anvil cellEarth and Planetary Science Letters, 1988
- The mineralogy and chemistry of the lower mantle: an implication of the ultrahigh-pressure phase relations in the system MgO FeO SiO2Earth and Planetary Science Letters, 1984
- Ferric iron in orthopyroxene: a Mössbauer spectroscopic studyLithos, 1978
- Applications of the Mössbauer effect to silicate mineralogy—I. Iron silicates of known crystal structureGeochimica et Cosmochimica Acta, 1967
- Phase Equilibria in the System MgO‐FeO‐Fe2O3: The 1300°C Isothermal Section and Extrapolations to Other TemperaturesJournal of the American Ceramic Society, 1967