Abstract
Olivine basalts from southern Egypt were studied by
57
Fe Mössbauer spectroscopy at 297 and 77 K, and by optical microscopy and X-ray diffraction. The
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Fe Mössbauer spectra show three-magnetic sextets, three doublets of ferrous (Fe
2+
), and a weak ferric (Fe
3+
) doublet that is attributable to a nanophase oxide (npOx). The magnetic sextets relate to titanomagnetite and the Fe
2+
doublets to olivine, pyroxene, and ulvöspinel. Variations in the hyperfine parameters of the various Fe components are attributed to changes in the local crystal chemistry. The intensity of oxidation (Fe
3+
/ΣFe) in the rocks varies from 20-27% with the oxidized iron largely residing in the titanomagnetite.