I have seen similar textures and compositions for cpx from
calc-silicate rocks at Cascade Slide, Adirondacks, NY, at a contact with
anorthosite. The texture is caused by a reaction involving CaTs to make
garnet. Various calc-silicate assemblages from that well known locality
were described by Tracy et al. (1979) and Valley and Essene (1980).
Megacrystic cpx from Salt Lake Crater, Hawaii show lamellar "exsolution"
of garnet where cooling of a near-liquidus CaTs-rich cpx produces garnet
(albeit not grandite but gralpyite), cf. Dave Green (1967? EPSL). The cpx
in many garnet clinopyroxenite and some grospydite xenoliths show similar
textures, which are probably produced by a similar process.
>We are working on a suite of calc-silicate granulites at the contact of an
>anorthosite body. We have got mesoperthite like intergrowth between garndite
>garnet (Grs65-75 Adr25-35) and clinopyroxene (Al2O3~ 4-6 wt%). The other
>minerals are wollastonite,scapolite with or without quartz. The Cpx grains
>devoid of garnet exsolution are highly aluminous (up to 11 wt% Al2O3).
>Please enlighten me about the natural occurrences where such an intergrowth
>between grandite and Cpx has been observed.
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