Geothermobarometry in staurolite-grade mica schists from the southern part of the Niemcza-Kamieniec Metamorphic Complex (Fore-Sudetic Block, SW Poland)
published: Sep 1, 2000
ArtNo. ESP154017503001, Price: 29.00 €
The southern part of the Niemcza-Kamieniec Metamorphic Complex (Fore-Sudetic Block, SW Poland) consists of mica schists forming two units: the Kamieniec Unit and the Byczeń Unit. The Kamieniec Unit schists are of staurolite grade, whereas those of Byczeń Unit were metamorphosed under greenschist facies conditions. Both the units contact through a transition zone formed by mica schists with staurolite and garnet. The geothermobarometry shows significant differences in metamorphic conditions between the schists of the Kamieniec Unit (590 ± 30 °C, 10.5 ± 1.5 kbar) and those of the transition zone (540 ± 35 °C, 7.5 ± 1.0 kbar). The temperatures calculated for the transition zone schists are about 30 °C lower than those predicted by petrogenetic grids. This is because in the Kamieniec Unit schists garnet crystallised simultaneously with staurolite and was not significantly involved in later metamorphic reactions, whereas in the transition zone schists staurolite post-dates garnet. The consumption of garnet rims during staurolite crystallisation causes lowering of metamorphic temperatures calculated using garnet-biotite geothermometer.