Are you analysing all your Fe as FeII or FeIII? In the latter case, this will
push the totals up a bit. At the end of the day you may have a mix of the two.
I'm fiddling around with garnets dominated by And-Grs and have little problem (we
also use a JXA-733 but with Advanced Microbeam's set up). I would not expect the
matrix corrections to be an issue. Just ensure that the standards you are using
have sufficient of the element you are interested in. I use a range of different
things and there isn't a grt in sight.
Cheers,
Malc.
Julie Vry wrote:
> I encounter persistent difficulties in analysing the Fe-Ca-Mn garnets
> (about 1/3 of each component) that are common on the NZ Southern Alps
> (usually I get about 103% totals). I suspect that the problem is in
> the matrix correction factors, but that is not easy for me to sort
> out.
>
> I wonder if using a garnet standard of similar composition might help...
> (I don't have such a standard)
>
> Any suggestions as to how I might deal with the problem would be appreciated.
> The probe (a 20+ year-old JEOL JXA-733 SuperProbe, using Moran
> Scientific software) works wonderfully except for this.
>
> Julie Vry
> --
> Dr. Julie Vry
> Senior Lecturer - Geology (metamorphic petrology)
> School of Earth Sciences
> Victoria University
> PO Box 600
> Wellington, New Zealand
>
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