Dunderlandsdalen. Fjeldbygningen inden gradavdelingskartet Dunderlandsdalens omraade

Abstract

This paper is a geological description of the Dunderland district in Nordland, a part of Northern Norway. The map accompanying the paper is a part of the official series of maps on the scale of 1:100 000, which is being published covering all Norway. The present map is the first in this series which has been published as a geological map. The author has in a previous paper divided Nordland into three regions: the granite region of the coast-zone (kystsonens granittregion) running parallel with coast-line and including larg masses of igneous rocks, principally granites. To the East of this region the inner region of schists (Den indre skiferregion or dalstrøkenes skiferregion) where sedimentary rocks as schists and limestone are predominant constituents. And thirdly, to the West of the granite region a similar zone of sedimentary rocks, the \"skjærgaardens\" region of schists (Skjærgaardens skiferregion). Dunderlandsdalen belong to the inner region of schists. Various types of mica schists are the ruling types of rocks within the area described. These rocks have sometimes the character of phyllitic schists, usually, however they are, more ordinary mica-schists very often with an abundance of garnets. Cyanite or disthene has been found in some cases as an accessory mineral.