Jump to main content
Jump to site search

Issue 10, 2012
Previous Article Next Article

Iron oxidation state in garnet from a subduction setting: a micro-XANES and electron microprobe (“flank method”) comparative study

Author affiliations

Abstract

The variation of the Fe-redox state across a strongly zoned garnet crystal occurring in a FeTi-oxide metagabbro from a subduction setting has been investigated comparing micro-XANES and electron microprobe (“flank method”) results. This sample represents an ideal monitor of the redox processes associated with devolatilization reactions occurring in the subducting slab and likely involved in the oxidation of the mantle wedge, as well as a challenge for the analytical methods. Since in the studied garnet the Fe3+/ΣFe variations are small and occur on a micrometric scale, we exploited the X-ray microprobe available at the ESRF ID22 beamline to reach a spot size of 1.7 μm × 5.3 μm. Our study represents a first attempt to measure the Fe3+/ΣFe variations across a single crystal of garnet, ca. 400 μm in diameter, using the micro-XANES technique. The absolute Fe3+/ΣFe values obtained with micro-XANES and “flank method” are perfectly comparable, ranging from a maximum of about 0.1 in the garnet core to a minimum of 0.0 in the garnet rim.

Graphical abstract: Iron oxidation state in garnet from a subduction setting: a micro-XANES and electron microprobe (“flank method”) comparative study

Back to tab navigation

Supplementary files

Publication details

The article was received on 18 May 2012, accepted on 31 Jul 2012 and first published on 01 Aug 2012


Article type: Paper
DOI: 10.1039/C2JA30149K
J. Anal. At. Spectrom., 2012,27, 1725-1733

  •   Request permissions

    Iron oxidation state in garnet from a subduction setting: a micro-XANES and electron microprobe (“flank method”) comparative study

    E. Borfecchia, L. Mino, D. Gianolio, C. Groppo, N. Malaspina, G. Martinez-Criado, J. A. Sans, S. Poli, D. Castelli and C. Lamberti, J. Anal. At. Spectrom., 2012, 27, 1725
    DOI: 10.1039/C2JA30149K

Search articles by author

Spotlight

Advertisements