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Zircon U-Pb and Hf - isotopes from the eastern part of the Sveconorwegian Orogen, SW Sweden : Implications for the growth of Fennoscandia

Petersson, Andreas LU ; Scherstén, Anders LU ; Andersson, Jenny LU and Möller, Charlotte LU (2015) In Geological Society Special Publication 389(1). p.281-303
Abstract

Current models for the growth of Fennoscandia, including the eastern part of the Sveconorwegian Province, are largely based on U-Pb data and do not discriminate between juvenile and reworked crust. Here we present new combined U-Pb and Hf isotopic data, from the Eastern Segment and the Idefjorden terrane of the Sveconorwegian Province, and suggest a revised model of crustal growth. Most of the crystalline basement in this part of the shield formed by mixing of a 2.1-1.9 Ga juvenile component and Archaean crust. Archaean reworking decreases between 1.9 and 1.7 Ga and a mixed Svecofennian crustal reservoir is generated. Succeeding magmatism between 1.7 and 1.4 Ga indicates reworking of this reservoir with little or no crust generation. At... (More)

Current models for the growth of Fennoscandia, including the eastern part of the Sveconorwegian Province, are largely based on U-Pb data and do not discriminate between juvenile and reworked crust. Here we present new combined U-Pb and Hf isotopic data, from the Eastern Segment and the Idefjorden terrane of the Sveconorwegian Province, and suggest a revised model of crustal growth. Most of the crystalline basement in this part of the shield formed by mixing of a 2.1-1.9 Ga juvenile component and Archaean crust. Archaean reworking decreases between 1.9 and 1.7 Ga and a mixed Svecofennian crustal reservoir is generated. Succeeding magmatism between 1.7 and 1.4 Ga indicates reworking of this reservoir with little or no crust generation. At c. 1.2 Ga, an influx of juvenile magma is recorded by granite to quartz-syenite magmatism with mildly depleted (εHf 1.18 Ga of c. 3) signatures. The amount of recycled crust in the 1.9- 1.7 Ga arc system is in contrast to previously proposed models for the growth of the southwestern part of the Fennoscandian Shield. This model agrees with long-term subduction along the western margin of Fennoscandia, but suggests substantial reworking of existing crust and decreasing amounts of <1.9 Ga crustal growth.

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organization
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Contribution to journal
publication status
published
subject
in
Geological Society Special Publication
volume
389
issue
1
pages
23 pages
publisher
Geological Society of London
external identifiers
  • scopus:84929847080
ISSN
0305-8719
DOI
10.1144/SP389.2
language
English
LU publication?
yes
id
8b791760-2804-412f-878a-59fa7601ddc2
date added to LUP
2016-05-24 09:01:55
date last changed
2017-09-10 05:06:30
@article{8b791760-2804-412f-878a-59fa7601ddc2,
  abstract     = {<p>Current models for the growth of Fennoscandia, including the eastern part of the Sveconorwegian Province, are largely based on U-Pb data and do not discriminate between juvenile and reworked crust. Here we present new combined U-Pb and Hf isotopic data, from the Eastern Segment and the Idefjorden terrane of the Sveconorwegian Province, and suggest a revised model of crustal growth. Most of the crystalline basement in this part of the shield formed by mixing of a 2.1-1.9 Ga juvenile component and Archaean crust. Archaean reworking decreases between 1.9 and 1.7 Ga and a mixed Svecofennian crustal reservoir is generated. Succeeding magmatism between 1.7 and 1.4 Ga indicates reworking of this reservoir with little or no crust generation. At c. 1.2 Ga, an influx of juvenile magma is recorded by granite to quartz-syenite magmatism with mildly depleted (ε<sub>Hf 1.18 Ga</sub> of c. 3) signatures. The amount of recycled crust in the 1.9- 1.7 Ga arc system is in contrast to previously proposed models for the growth of the southwestern part of the Fennoscandian Shield. This model agrees with long-term subduction along the western margin of Fennoscandia, but suggests substantial reworking of existing crust and decreasing amounts of &lt;1.9 Ga crustal growth.</p>},
  author       = {Petersson, Andreas and Scherstén, Anders and Andersson, Jenny and Möller, Charlotte},
  issn         = {0305-8719},
  language     = {eng},
  month        = {05},
  number       = {1},
  pages        = {281--303},
  publisher    = {Geological Society of London},
  series       = {Geological Society Special Publication},
  title        = {Zircon U-Pb and Hf - isotopes from the eastern part of the Sveconorwegian Orogen, SW Sweden : Implications for the growth of Fennoscandia},
  url          = {http://dx.doi.org/10.1144/SP389.2},
  volume       = {389},
  year         = {2015},
}