Dominique and all,
Yes, the effect you mention has been repeatedly documented.
Resorption can also occur without seein retrograde zoning in garnet.
Chlorite can simply replace the former margins of the garnet.
eric
On Monday, July 12, 2004, at 10:00 AM, Laduron wrote:
> My comment, in agreement with other previous comments, is that
> "resorption" implies "textural modification" -in this case, size or
> form of the
> garnet grains- which is not always evident.
> For me, "resorption" can be also established by "microprobe profile"
> across several garnet grains (porphyroblasts or not) in the same thin
> section which show "reverse zoning" around the grains with a variable
> shortening of the "normal zoning".
> It is also important to not forget that "resorption" -a concept
> different of "retrogression"- is possible during prograde or
> retrograde metamorphism.
> In the same context, an other important aspect to consider, is the
> "refractory character" of the garnet in the context of "solid state
> reaction".
>
> For example, with the "textural evidence" and "microprobe profile" see
> the following papers of what I was a co-author :
> P.de Bethune et al,. 1968, Bull.Suisse, Min.Petr., 48, 437-454.
> P.de Bethune and al., 1975, Contrib.mineral.Petrol., 50, 197-204
> J.Desmons et al., 1977, Mém.Inst.Géol.Univ.Louvain, t.29, 327-347.
> D.Laduron et al., 1981, Mém.Inst.Géol.Univ.Louvain, t.31, 335-347.
>
> With best wishes.
>
> Dominique
>
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