Geological map of Fennoscandia.
  Archean rocks of the Karelia, Belomorian and Kola domains
  Proterozoic rocks of the Karelia and Kola domains
  Sveconorwegian Orogen inc. the Western Gneiss Region

The Sveconorwegian orogeny was an orogenic system active 1140 to 960 million years ago and currently exposed as the Sveconorwegian orogenic belt in southwestern Sweden and southern Norway.[1][2] In Norway the orogenic belt is exposed southeast of the front of the Caledonian nappe system and in nappe windows.[3] The Sveconorwegian orogen is commonly grouped within the Grenvillian Mesoproterozoic orogens.[4] Contrary to many other known orogenic belts the Sveconorwegian orogens eastern border does not have any known suture zone with ophiolites.[3]

Tectonic segments

The Sveconorwegian orogen orogenic belt is composed of five segments largely made up of gneiss that were disrupted by both extension and compression in the timespan between 1140 and 980 million years ago.[1] From west to east the segments are the terranes of Telemarkia, Bamble, Kongsberg and Idefjorden plus the Eastern Segment. The segments are separated from each other by large-scale shear zones.[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. This episode, known as the Agder phase, was followed by the Falkenberg phase that lasted until 970 million years ago during which the orogeny propagated eastward.[5] There are differing views on the nature of the orogeny. 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. These different views have implications for the configuration of the ancient supercontinent Rodinia.[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.[10]


  1. ^ a b Andesson, Jenny; Bingen, Bernard; Cornell, David; Johansson, Leif; Möller, Charlotte (2008). "The Sveconorwegian orogen of southern Scandinavia: setting, petrology and geochronology of polymetamorphic high-grade terranes". 33 IGC excursion No 51, August 2 – 5.
  2. ^ "Sveconorwegian Orogen". Retrieved 26 August 2015.
  3. ^ a b c d e Bingen, Bernard; Nordgulen, Øystein; Viola, Giulio (2008). "A four-phase model for the Sveconorwegian orogeny, SW Scandinavia". Norwegian Journal of Geology. 88: 43–72.
  4. ^ a b c d Slagstad, Trond; Roberts, Nick M. W.; Markens, Rogens; Røhr, Torkil; Schiellerup, Henrik (2013). "A non-collisional, accretionary Sveconorwegian orogen". Terra Nova. 25: 30–37. doi:10.1111/ter.12001.
  5. ^ a b c d e f Viola, G.; Henderson, I.H.C.; Bingen, B.; Hendriks, B.W.H. (2011). "The Grenvillian–Sveconorwegian orogeny in Fennoscandia: Back-thrusting and extensional shearing along the "Mylonite Zone"". Precambrian Research. 189: 368–388. doi:10.1016/j.precamres.2011.06.005.
  6. ^ a b c d e Bingen, Bernard; Andersson, Jenny; Söderlund, Ulf; Möller, Charlotte (2008). "The Mesoproterozoic in the Nordic countries". Episodes. 31 (1): 29–34.
  7. ^ Gorbatschev, Roland; Bogdanova, Svetlana (1993). "Frontiers in the Baltic Shield". Precambrian Research. 64: 3–21. doi:10.1016/0301-9268(93)90066-b.
  8. ^ Möller, Charlotte; Andersson, Jenny; Dyck, Brendan; Ildiko Antal, Lundin (2015). "Exhumation of an eclogite terrane as a hot migmatitic nappe, Sveconorwegian orogen". Lithos. 226: 147–168. doi:10.1016/j.lithos.2014.12.013.
  9. ^ Austrheim, Håkon; Corfu, Fernando; Bryhni, Inge; Andersen, Torgeir B. (2003). "The Proterozoic Hustad igneous complex: a low strain enclave with a key to the history of the Western Gneiss Region of Norway" (PDF). Precambrian Research. 120: 149–175. doi:10.1016/S0301-9268(02)00167-5.
  10. ^ Schouenborg, Björn; Eliasson, Thomas (2015). The Swedish Bohus granite - a stone with a fascinating history. EGU General Assembly. Vienna, Austria. Bibcode:2015EGUGA..1714883S.