Dear Pulak,
I note that some of the respondents (Antonio Garcia Casco, Jochen Mezger)
express doubts about garnet-andalusite-garnet-staurolite-muscovite
constituting an equilibrium assemblage. Another area where the
"assemblage" is common, but demonstrably not an real equilibrium
assemblage, is the late-Proterozoic Wadi-Kid metamorphic belt in eastern
Sinai.
Andalusite-staurolite-garnet-biotite-muscovite schists are common in the
Umm-Zariq Formation in the upper Wadi Kid : however, syn-D2 andalusite and
locally staurolite enclose pre-D2 garnet, and locally andalusite mantles
staurolite.
Here and probably elsewhere, unravelling these "assemblages" using the
deformational phases of deformation is a useful approach .
References :
Blasband, B. et al. 1997, A Pan-African core complex in the Sinai, Egypt.
Geologie en Mijnbouw 76, 247-266
Blasband, B. et al. 2000, Late-Proterozoic extensional collapse in the
Arabian-Nubian Shield. J. Geol. Soc. London 157, 615-628
Reymer, A.P.S. et al. 1984, Pressure-temperature conditions in the Wadi Kid
metamorphic complex ..... Contr. Miner. and Petrol. 85, 336-345.
Shimron, A.E. 1984, Evolution of the Kid Group, southeast Sinai Peninsula
... Geology 12, 242-247.
Regards
Hanan Kisch
Prof. Hanan J. Kisch
Department of Geological and Environmental Sciences
Ben-Gurion University of the Negev
P.O.B. 653, Beer-Sheva 84105, Israel
Tel.: +972 8 646 1290
Fax (Dept office): +972 8 647 2997 and +972 8 647 7655
E-mail: [log in to unmask]
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