Sveconorwegian orogeny

[5] The period between 1050 and 980 million years ago was the Sveconorwegian orogeny's most active phase with the Telemarkia and Idefjord Terranes being subject to metamorphism, thickening of their crust and deformation.

One view, known as the "classical", postulates that a continent–continent collision, possibly with Amazonia, was responsible for giving the orogenic belts its current characteristics.

An alternative view postulated in 2013 claims such collision did likely not occur as the characteristics of the orogen would be explained solely as the result of subduction and accretion of smaller terranes.

[4] The southern part of what would eventually become the Western Gneiss Region of Norway formed migmatites and was intruded by granites during the orogeny.

[9] About 920 million years ago, in the aftermath of the orogeny, Bohus granite intruded the Idefjorden terrane.