En geologisk undersøkelse på den sørøstre del av kartbladet Salangen.

Abstract

Petrographic and structural investigations were made in a Cambro-Ordovician area of the Caledonides of Northern Norway, situated in Salangen, Troms. The rocks, mainly mica schists rich in biotite and\/or muscovite, are mostly folded and the schistosity is very distinct. This group of rocks also comprises light gneisses rich in microcline; probably they represent metamorphic sediments. In the upper parts of the sequence are found some amphibolites and layers with large hornblende crystals in the mica schist. Crystalline limestones occur in the lower parts, the zones are always less than 20-30 meters in thickness. Precambrian granite represent windows at the bottom of the Salangen valley. A Caledonian granite is intruded in the schists near Lavangen. Analysis, norm and mode of the last mentioned granite are given. The mineral assemblies suggest that the rocks are in the lower part of the almandine-amphibolite facies. Albite is the common feldspar in the rocks and the biotite isograd as well as the garnet isograd are exceeded in the area. The described rocks lies in the continuation of the Håfjell synclinorium in Ofoten. A north-north-east direction of the strike combined with dip to the west certifies this. Folding on almost horizontal axes trending along the main Caledonian direction is combined with north-east cross-folds.