The present studies in the northwesternmost part of the Western Gneiss Region, Norway, have demonstrated the existence of previously unknown metasediments and metavolcanics in the Caledonian nappe units. Tectonic and metamorphic breaks as well as lithological differences separate these units from the underlying migmatized gneissic granites and granodiorites. Structural concordance between basement and cover developed as a result of high strain induced by nappe translation. An intense interfolding of basement and cover units postdated the thrusting event. Metamorphic and lithological contrasts in the area are generally preserved. Garnet-biotite thermometry data suggest that the temperatures during post-thrusting metamorphism did not exceed 600°C. Later movements were cataclastic in character and often occurred parallel to older thrust planes.