Precambrian basement complexes in the North-Central Scandinavian Caledonides and their pre-Caledonian tectonic evolution

Abstract

Precambrian basement lithology, as exposed in four tectonic windows of the northcentral Scandinavian Caledonides, comprises uniform sequences of metasedimentary mica schists and gneisses (Borgefjell) as well as mica schists dominated by acid metavolcanics (Bangonaive) with minor basic rocks. The major part, however, is made up of intrusive rocks. Older granites are distributed in the Borgefjell area and to the east of it, obviously related to the Svecofennian Revsund granites. Younger granodiorites/quartzsyenites, subordinate in the Borgefjellet, dominate the Bangonaive window.