A preliminary account of the geology of the Signaldalen-Upper Skibotndalen area, Inner Troms, N. Norway.
MetadataVis full innførsel
- Artikler 
A preliminary account of the petrography, stratigraphy and structure of an area at the Caledonian front in inner Troms, N. Norway, is given. Precambrian autochthonous gneisses are overlain by autochthonous and par-autochthonous Cambrian sediments - the Hyolithus Zone. These are themselves overlain by Caledonian thrust metamorphics, divided into the Lower and Upper Allochthonous units. The lower unit consists mostly of quartzo-feldspathic phyllonites, which may be mainly sedimentary in origin. It is bordered below and above by low angle thrusts. The Upper Allochthonous unit has a very varied lithology of calcareous, quartzitic, pelitic and basic rocks all in a fairly advanced Metamorphic state. Some of the rock boundaries (especially quartzites) are tectonic. A provisional stratigraphy is suggested but this is uncertain due to the structural complexities in the area. At least one early period of isoclinal folding is recognized, and the main thrusting is associated with this. These structures were refolded by a system of open NW-SE folds and a possibly later system of gentle NE-SW flexures. The regional significance of this structural history is discussed.