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Subduction-flip during Iapetus Ocean closure and Baltica-Laurentia collision, Scandinavian Caledonides

Andréasson, Per-Gunnar LU ; Gee, DG; Whitehouse, MJ and Schoberg, H (2003) In Terra Nova: the European journal of geosciences 15(6). p.362-369
Abstract
Evidence is presented here from the northern Scandinavian Caledonides for development of an extensional basin of Ashgill to Mid Llandovery age along the Baltoscandian margin immediately prior to Baltica-Laurentia collision. U/Pb multigrain and ion microprobe zircon dating of plagiogranites in the Halti Igneous Complex complement previous baddeleyite and zircon dating of a dolerite dyke, and zircon dating of anatectic granite; they demonstrate that this dunite, troctolite, gabbro, sheeted-dyke complex ranges in age from c. 445 to 435 Ma. The dolerite dykes intruded and melted arkoses of inferred Neoproterozoic age. This evidence, taken together with previous documentation of ophiolites (Solund-Stavfjord), ophiolite-like associations... (More)
Evidence is presented here from the northern Scandinavian Caledonides for development of an extensional basin of Ashgill to Mid Llandovery age along the Baltoscandian margin immediately prior to Baltica-Laurentia collision. U/Pb multigrain and ion microprobe zircon dating of plagiogranites in the Halti Igneous Complex complement previous baddeleyite and zircon dating of a dolerite dyke, and zircon dating of anatectic granite; they demonstrate that this dunite, troctolite, gabbro, sheeted-dyke complex ranges in age from c. 445 to 435 Ma. The dolerite dykes intruded and melted arkoses of inferred Neoproterozoic age. This evidence, taken together with previous documentation of ophiolites (Solund-Stavfjord), ophiolite-like associations (Sulitjelma Igneous Complex) and several other mafic suites (e.g. Rana, Artfjallet) of Ashgill to Llandovery age further south in the northern Scandinavian Caledonides, implies that Scandian collisional orogeny along this nearly 2000-km-long mountain belt was immediately preceeded by development of short-lived marginal basins. The latter developed during the final closure of the Iapetus Ocean and are inferred to be of back-arc origin, some (perhaps all) related to E-dipping subduction. Collision of the continents at c. 435 Ma is inferred to have induced a flip in subduction polarity, leading to underthrusting of Laurentia by Baltica. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Terra Nova: the European journal of geosciences
volume
15
issue
6
pages
362 - 369
publisher
Wiley-Blackwell
external identifiers
  • wos:000187257100001
  • scopus:0346462886
ISSN
0954-4879
DOI
10.1046/j.1365-3121.2003.00486.x
language
English
LU publication?
yes
id
4c995dc1-6833-4e2b-9d6e-78a2885a1d4d (old id 292536)
date added to LUP
2007-08-22 12:25:57
date last changed
2018-05-29 11:06:08
@article{4c995dc1-6833-4e2b-9d6e-78a2885a1d4d,
  abstract     = {Evidence is presented here from the northern Scandinavian Caledonides for development of an extensional basin of Ashgill to Mid Llandovery age along the Baltoscandian margin immediately prior to Baltica-Laurentia collision. U/Pb multigrain and ion microprobe zircon dating of plagiogranites in the Halti Igneous Complex complement previous baddeleyite and zircon dating of a dolerite dyke, and zircon dating of anatectic granite; they demonstrate that this dunite, troctolite, gabbro, sheeted-dyke complex ranges in age from c. 445 to 435 Ma. The dolerite dykes intruded and melted arkoses of inferred Neoproterozoic age. This evidence, taken together with previous documentation of ophiolites (Solund-Stavfjord), ophiolite-like associations (Sulitjelma Igneous Complex) and several other mafic suites (e.g. Rana, Artfjallet) of Ashgill to Llandovery age further south in the northern Scandinavian Caledonides, implies that Scandian collisional orogeny along this nearly 2000-km-long mountain belt was immediately preceeded by development of short-lived marginal basins. The latter developed during the final closure of the Iapetus Ocean and are inferred to be of back-arc origin, some (perhaps all) related to E-dipping subduction. Collision of the continents at c. 435 Ma is inferred to have induced a flip in subduction polarity, leading to underthrusting of Laurentia by Baltica.},
  author       = {Andréasson, Per-Gunnar and Gee, DG and Whitehouse, MJ and Schoberg, H},
  issn         = {0954-4879},
  language     = {eng},
  number       = {6},
  pages        = {362--369},
  publisher    = {Wiley-Blackwell},
  series       = {Terra Nova: the European journal of geosciences},
  title        = {Subduction-flip during Iapetus Ocean closure and Baltica-Laurentia collision, Scandinavian Caledonides},
  url          = {http://dx.doi.org/10.1046/j.1365-3121.2003.00486.x},
  volume       = {15},
  year         = {2003},
}