The Scandinavian ‘Mountain Problem’

Abstract

A General feature in the geological structure of the eastern zone of the Caledonian mountain-range of the Scandinavian Peninsula is the existence of highly metamorphic, often gneissose, unfossiliferous rocks above slightly-altered fossiliferous Cambro-Silurian sediments. This feature is met with from the Stavanger district in the south to Finmarken in the north. It is now more than thirty years since the Swedish geologist A. E. Törnebohm 1 suggested that this remarkable feature, this mountain problem' of Scandinavia, might be explained by employing the overthrust theory: by assuming, as had proved to be the fact in Scotland, that the overlying metamorphic rocks originally belonged to the pre-Cambrian System, and by means of an enormous thrust had been brought into their present position above what was left of the Cambro-Silurian sedimentary series. After further investigations, inter alia in the Norwegian mountain-district of Jotunheimen (see map, fig. 1, p. 388), Törnebohm became increasingly convinced of the correctness of this view, of the ancient date of, for instance, those metamorphic stratified rocks of Central and South-Western Southern Norway for which the Norwegian investigator Th. Kjerulf had established the term ‘höifjeldskvarts’: that is, ‘Highland Quartz’ (or Highland Quartzite). In 1896 appeared Törnebohm's famous paper2 on the geological structure of Central Scandinavia, in which, among others, the well-known sections from the Trondhjem district of Norway in the west, into Jemtland in Sweden in the east, showing an immense overthrust from west to east, were published. During subsequent years Törnebohm's views were taken up by several other Swedish investigators: