Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden)
The collision of Baltica and Laurentia during the Caledonian Orogeny happened at c. 400–420 Ma. However, subduction and collision processes also took place before this main collisional phase and the tectonic history of these is still not fully resolved. The Seve Nappe Complex in Sweden has recorded...
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2021
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Online Access: | http://hdl.handle.net/10261/270108 https://doi.org/10.1111/jmg.12591 |
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ftcsic:oai:digital.csic.es:10261/270108 2024-02-11T10:06:57+01:00 Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) Fassmer, Kathrin Froitzheim, Nikolaus Janák, Marian Strohmeyer, Merle Bukała, Michal Lagos, Markus Münker, Carsten 2021-01-09 http://hdl.handle.net/10261/270108 https://doi.org/10.1111/jmg.12591 unknown Wiley-Blackwell Publisher's version http://dx.doi.org/10.1111/jmg.12591 Sí doi:10.1111/jmg.12591 issn: 1525-1314 Journal of Metamorphic Geology 39: 819- 842 (2021) http://hdl.handle.net/10261/270108 open Caledonian Orogeny Garnet High-P metamorphism Lu–Hf geochronology Seve Nappe Complex artículo http://purl.org/coar/resource_type/c_6501 2021 ftcsic https://doi.org/10.1111/jmg.12591 2024-01-16T11:24:42Z The collision of Baltica and Laurentia during the Caledonian Orogeny happened at c. 400–420 Ma. However, subduction and collision processes also took place before this main collisional phase and the tectonic history of these is still not fully resolved. The Seve Nappe Complex in Sweden has recorded these earlier phases. The Seve Nappe Complex in Norrbotten (North Swedish Caledonides) comprises four superimposed nappes emplaced by eastward thrusting (from base to top according to the conventional structural interpretation): Lower Seve Nappe, Vaimok, Sarek, and Tsäkkok Lenses. Eclogites occur in the Vaimok and Tsäkkok Lenses. The Vaimok Lens represents rocks of the Baltican continental margin intruded by Neoproterozoic dolerite dikes which were later eclogitized and boudinaged. By contrast, eclogites of the Tsäkkok Lens are former oceanic basalts associated with calcschists, possibly representing the ocean–continent transition between Baltica and Iapetus. Previous age determinations for eclogitization yielded various ages between c. 500 and 480 Ma, in contrast to younger (460–450 Ma) ages of ultra high-P metamorphism in the Seve Nappe Complex further south in Jämtland. Eclogites from the Vaimok (one sample) and Tsäkkok (three samples) lenses were dated using Lu–Hf garnet geochronology. Garnet from all samples shows prograde zoning of major element and Lu contents and yielded well-defined isochrons of the following ages: 480.4 ± 1.2 Ma (Vaimok); 487.7 ± 4.6 Ma, 486.2 ± 3.2, 484.6 ± 4.6 Ma (Tsäkkok). The ages from Tsäkkok are interpreted to date the burial of the Iapetus–Baltica ocean–continent transition in a west-dipping subduction zone around c. 485 Ma, and the age from the structurally deeper Vaimok Nappe the following subduction of the continental margin. Previously reported ages of 500 Ma and older are not supported by this study. The age difference between eclogites in the Seve Nappe Complex in Jämtland (c. 460–450 Ma) and Norrbotten (c. 488–480 Ma) may reflect the collision of an island arc with an ... Article in Journal/Newspaper North Sweden Norrbotten Digital.CSIC (Spanish National Research Council) Sarek ENVELOPE(17.500,17.500,67.350,67.350) Tsäkkok ENVELOPE(16.783,16.783,67.067,67.067) Vaimok ENVELOPE(16.896,16.896,67.033,67.033) Journal of Metamorphic Geology 39 7 819 842 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
unknown |
topic |
Caledonian Orogeny Garnet High-P metamorphism Lu–Hf geochronology Seve Nappe Complex |
spellingShingle |
Caledonian Orogeny Garnet High-P metamorphism Lu–Hf geochronology Seve Nappe Complex Fassmer, Kathrin Froitzheim, Nikolaus Janák, Marian Strohmeyer, Merle Bukała, Michal Lagos, Markus Münker, Carsten Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) |
topic_facet |
Caledonian Orogeny Garnet High-P metamorphism Lu–Hf geochronology Seve Nappe Complex |
description |
The collision of Baltica and Laurentia during the Caledonian Orogeny happened at c. 400–420 Ma. However, subduction and collision processes also took place before this main collisional phase and the tectonic history of these is still not fully resolved. The Seve Nappe Complex in Sweden has recorded these earlier phases. The Seve Nappe Complex in Norrbotten (North Swedish Caledonides) comprises four superimposed nappes emplaced by eastward thrusting (from base to top according to the conventional structural interpretation): Lower Seve Nappe, Vaimok, Sarek, and Tsäkkok Lenses. Eclogites occur in the Vaimok and Tsäkkok Lenses. The Vaimok Lens represents rocks of the Baltican continental margin intruded by Neoproterozoic dolerite dikes which were later eclogitized and boudinaged. By contrast, eclogites of the Tsäkkok Lens are former oceanic basalts associated with calcschists, possibly representing the ocean–continent transition between Baltica and Iapetus. Previous age determinations for eclogitization yielded various ages between c. 500 and 480 Ma, in contrast to younger (460–450 Ma) ages of ultra high-P metamorphism in the Seve Nappe Complex further south in Jämtland. Eclogites from the Vaimok (one sample) and Tsäkkok (three samples) lenses were dated using Lu–Hf garnet geochronology. Garnet from all samples shows prograde zoning of major element and Lu contents and yielded well-defined isochrons of the following ages: 480.4 ± 1.2 Ma (Vaimok); 487.7 ± 4.6 Ma, 486.2 ± 3.2, 484.6 ± 4.6 Ma (Tsäkkok). The ages from Tsäkkok are interpreted to date the burial of the Iapetus–Baltica ocean–continent transition in a west-dipping subduction zone around c. 485 Ma, and the age from the structurally deeper Vaimok Nappe the following subduction of the continental margin. Previously reported ages of 500 Ma and older are not supported by this study. The age difference between eclogites in the Seve Nappe Complex in Jämtland (c. 460–450 Ma) and Norrbotten (c. 488–480 Ma) may reflect the collision of an island arc with an ... |
format |
Article in Journal/Newspaper |
author |
Fassmer, Kathrin Froitzheim, Nikolaus Janák, Marian Strohmeyer, Merle Bukała, Michal Lagos, Markus Münker, Carsten |
author_facet |
Fassmer, Kathrin Froitzheim, Nikolaus Janák, Marian Strohmeyer, Merle Bukała, Michal Lagos, Markus Münker, Carsten |
author_sort |
Fassmer, Kathrin |
title |
Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) |
title_short |
Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) |
title_full |
Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) |
title_fullStr |
Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) |
title_full_unstemmed |
Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) |
title_sort |
diachronous collision in the seve nappe complex: evidence from lu–hf geochronology of eclogites (norrbotten, north sweden) |
publisher |
Wiley-Blackwell |
publishDate |
2021 |
url |
http://hdl.handle.net/10261/270108 https://doi.org/10.1111/jmg.12591 |
long_lat |
ENVELOPE(17.500,17.500,67.350,67.350) ENVELOPE(16.783,16.783,67.067,67.067) ENVELOPE(16.896,16.896,67.033,67.033) |
geographic |
Sarek Tsäkkok Vaimok |
geographic_facet |
Sarek Tsäkkok Vaimok |
genre |
North Sweden Norrbotten |
genre_facet |
North Sweden Norrbotten |
op_relation |
Publisher's version http://dx.doi.org/10.1111/jmg.12591 Sí doi:10.1111/jmg.12591 issn: 1525-1314 Journal of Metamorphic Geology 39: 819- 842 (2021) http://hdl.handle.net/10261/270108 |
op_rights |
open |
op_doi |
https://doi.org/10.1111/jmg.12591 |
container_title |
Journal of Metamorphic Geology |
container_volume |
39 |
container_issue |
7 |
container_start_page |
819 |
op_container_end_page |
842 |
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1790604993525448704 |