Kyanite-grade metamorphism in the Evenes and Bogen Groups, Ofoten, North Norway

Directly north of Ofotfjorden in northern Norway, pelitic schists within the Evenes and Bogen Groups contain the mineral assemblage garnet + biotite ± kyanite ± staurolite + white mica + quartz ± plagioclase.
This assemblage implies metamorphic P-T minima of ˜ 540°C and ˜ 4. 8 kb. The rocks are thus at a higher grade than suggested by previous reports, which placed them in the greenschist facies. This indicates that several metamorphic allochthons in Ofoten, including rocks of the Narvik, Evenes, Bogen, and Niingen Groups, are all at kyanite grade, supporting recent interpretations which on structural grounds concluded that the metamorphic peak outlasted stacking of these allochthons. A proposed correlation of the Evenes Group with the Middle Ordovician-Lower Silurian Balsfjord Supergroup implies that this stacking and associated kyanite-grade metamorphism are post-early Silurian and are
related to the Scandian phase of the Caledonian orogeny.