The rocks have undergone several periods of regional metamorphism, to at least upper amphibolite facies, and there was a subsequent phase of retrograde metamorphism.
12.
If burial continues along Barrovian Sequence metamorphic trajectories, greenschist facies gives rise to amphibolite facies assemblages, dominated by amphibole and eventually to granulite facies.
13.
S1 schistosity is defined by hornblende and chlorite, and this mineralogical association suggests that the deformation occurred under upper greenschist to lower amphibolite facies conditions.
14.
Amphibolite facies conditions are experienced at temperatures in excess of 500 �C and pressures less than 1.2 GPa, well within the ductile deformation field.
15.
The original 20 30 m thick Homestake Formation, has been deformed and metamorphosed, resulting in upper greenschist facies of siderite-phyllite, and lower amphibolite facies of grunerite schists.
16.
At amphibolite facies, the diopside-in isograd is reached ( dependent on carbon dioxide partial pressure ) and metamorphic assemblages trend toward talc-pyroxene and eventually toward metamorphic olivine.
17.
It consists of Proterozoic orthogneisses and early Paleozoic sedimentary ( pelites, calcareous schists and marbles ) rocks that were metamorphosed at high grade during the Hercynian orogeny ( up to amphibolite facies ).
18.
The deposits show evidence of an Early Cretaceous, amphibolite facies event and a younger, mid-Cretaceous lower greenschist facies event which resulted from the accretion of the Yukon-Tanana Terrane.
19.
The now high-grade metamorphic rocks essentially the amphibolite facies with medium-pressure high-temperature conditions was reached-were originally deposited as flysch sequences along Gondwanas northern continental slope.
20.
The metamorphic grade increases gradually from the Prince Olav Coast ( amphibolite facies; eastern part of the LHC ) to the Soya Coast ( granulite facies; western part of the LHC ).
