Trondheimsfeltet
The Trondheimsfeltet is a mountainous landscape in the Norwegian province of Trøndelag . It extends roughly from Trondheimfjord south to northern Gudbrandsdalen .
geology
The mountains in the Trondheimsfeltet were formed by displacement from the northwest, mainly from the Cambrian to the Silurian , but only acquired their present-day appearance through metamorphosis in the course of the Caledonian orogeny . The dominant near-surface rock types are mainly sandstone , mica schist , slate , limestone and intrusive rocks such as gabbro , oppdalitt , and trondhjemitt . In the limestone and shale layers there are numerous fossils that are more like the fossil fauna of North America than that of Scandinavia . The individual rock types in Trondheimsfeltet are often in the four groups Gulagruppen , Størengruppen , Hovingruppen and Horggruppen divided.
A high pyrite content in the rock made it possible to mine this raw material profitably in many places in the Trondheimsfeltet , for example in Løkken Verk , in parts of the Røros copper mine and in the Folldal mine .