Dear colleagues
I have been studying gneisses from
Erzgebirge, which have mineral assemblage quartz-Kfs-Pl-Ms-Bt. To
constrain P-T conditions of their metamorphism, I can use phengite
barometry - however, determination of temperatures seems to be
difficult. At least muscovite is outside the compositional range defined by
Hoisch (1989) biotite-muscovite thermometer, being too Mg-rich.
I will be grateful to any advice or comment
from those who have experience with this and other thermobarometers (e.g. Green
and Usdansky 1986 based on Na-K exchange reaction between Pl and Ms, and
more recent ones), which could be used for these rocks.
Thank you in advance!
Dr. Jana Kotkova
Czech Geological
Survey
Klarov 3
118 21 Praha 1
Czech
Republic
