Print

Print


At 09:00 15.6.01 -0600, you wrote:
>Does anyone know of occurrences of the following rather rare metamorphic
>mineral assemblage:
>
>Muscovite+Chloritoid+chlorite+Al2SiO5 mineral (with or without biotite)
>
>Okuyama-Kusunose (J Met Geol 1994) reports extensive development of
>MsChlCtdBt and MsCtdAndBt in metamorphosed lateritic pelites in the Tono
>aureole, Japan, and alludes to the occurrence of MsCtdChlAnd(without Bt).
>
>The most likely rock types for these assemblages are aluminous metapelites,
>aluminous quartzites and metamorphosed altered felsic volcanics.
>
>
>
>David R.M. Pattison, Department of Geology and Geophysics,
>University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
>Phone: 403-220-3263 (my office); 403-220-5841 (dept. office)
>Fax: 403-284-0074     email: [log in to unmask]
>
---------------
David,
Similar Metamorphic mineral assemblage is described in high-Al metapelites
from the North-western Rila Mt., Bulgaria:
Kolcheva, K., Z. Cherneva. 1999. Metamorphic evolution of metapelites from
the North-western Rila Mt. - Geochem., Mineral. and Petrol., 36, 45-66.

We have recognised three mineral forming phases with chloritoid in the last one:
F1: Grt1 + Qtz1 + Rt1
F2: Grt2 + Ms2 + Chl2 + Ky + Sil + Qtz2 + St + Pl2 + Bt2 + Ilm
F3: And + Cld + Ms3 + Chl3 + Qtz3

You can find an attached abstract.

Best regards
Zlatka