Dear Ioannis,
Specific references don't come to mind just now, but I wonder if this is
similar to the situation in certain orthogneisses within the Tauern
Window, Eastern Alps, where re-equilibrated igneous plagioclase in
meta-tonalite and meta-granodiorite contains small garnets in addition
to clinozoisite and white mica (the so-called "gefuellte" feldspars).
This arises from the expulsion of Al- and Ca-rich anorthite component
from the original andesine to give a more sodic plagioclase plus these
precipitated products. The metamorphic grade here is at the
greenschist/amphibolite boundary.
Dave
Ioannis Iliopoulos wrote:
>
> Dear all,
>
> I am working on metamorphic rocks from Ikaria island (Greece) which belong
> toAttic-Cycladic Metamorphic Belt. Metamorphic conditions range from
> greenschist to medium amphibolitic grade. In both metabasites and
> metapelites, I often find abundant garnet inclusions in plagioclase
> crystals. Whenever garnet is present as inclusion in plagioclase then the
> latter is oligoclase. If plagioclase is free of garnet inclusions (and
> garnet exists only in the main matrix of the rock), then its composition is
> more close to andesine.
>
> I would appreciate if anybody could let me know about references
> encountering similar situation.
>
> Best regards,
> Ioannis
>
> __________________________________
> Ioannis Iliopoulos
> Section of Earth Materials, Dept. of Geology
> University of Patras, 26500 Patras, Greece
> Tel: +30 2610 996305 Fax: +30 2610 997560
> email: [log in to unmask]
--
Dave Waters - Lecturer in Metamorphic Petrology, Oxford University
Dept of Earth Sciences, Parks Rd, Oxford OX1 3PR, UK
Tel: +44 1865 272000
Direct: +44 1865 272058 Email: [log in to unmask]
Fax: +44 1865 272072 http://www.earth.ox.ac.uk/~davewa/
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