Mössbauer study of amphiboles originated from the Carpathian region

Abstract

Mössbauer spectroscopy was used in order to get information about the differences in the geological occurences at the different areas by investigating the distribution of iron in various crystallographic positions in amphiboles originated from the Carpathian region. The spectra of amphibole samples can be decomposed into doublets corresponding to Fe²⁺ and Fe³⁺ in different crystallographic sites. In the case of spectra recorded up to very high counts a distinction of the M1, M2, M3 and M4 positions occupied by Fe²⁺ was achieved. In contrast to previous investigations, two different doublets of Fe³⁺ were found in each spectrum. These can be associated with Fe³⁺ substituted tetrahedrally as well as in M1, M2, and M3 sites. Dramatic changes in Fe²⁺/Fe³⁺ ratio were observed among the amphiboles (found to be similar by microscopic studies) originated from Mecsek Mts, Balaton Highland and other localities. Consequently, conclusion were drawn for the differences in formation of amphiboles.