IRON SITE POPULATIONS FROM MOSSBAUER-SPECTROSCOPY IN TI-BEARING GARNETS FROM MT VULTURE (ITALY)

The present work concerns the determination of the cation site populat ions and crystal chemical formulae of some Ti-rich silicate garnets. T he samples come from Mt. Vulture, a volcanic complex located on the ea st side of the Lucania Apennines (south Italy). Mossbauer spectroscopy (MS) has been used in order to obtain the iron site occupancies. Two different models for interpreting the Fe2+ peak positions in the Mossb auer spectra are compared, and some methodological aspects are discuss ed. The derived iron distributions have then been combined with the da ta obtained by electron probe microanalysis (EPMA) and single-crystal X-ray diffraction analysis (XRD) to obtain consistent crystal chemical formulae for these compounds.