Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden)
Agentúra na Podporu Výskumu a Vývoja, Grant/Award Number: APVV-18- 0107; Deutsche Forschungsgemeinschaft, Grant/ Award Number: FR700/18-1 We thank Christopher Barnes (AGH University of Science and Technology, Kraków) for providing us with some of the studied samples. Kathrin Fassmer thanks Svenja Tr...
Published in: | Journal of Metamorphic Geology |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley-Blackwell Publishing
2021
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Subjects: | |
Online Access: | http://hdl.handle.net/10481/68383 https://doi.org/10.1111/jmg.12591 |
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ftunivgranada:oai:digibug.ugr.es:10481/68383 |
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Open Polar |
collection |
DIGIBUG: Repositorio Institucional de la Universidad de Granada |
op_collection_id |
ftunivgranada |
language |
English |
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 Bukała, Michał 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 |
Agentúra na Podporu Výskumu a Vývoja, Grant/Award Number: APVV-18- 0107; Deutsche Forschungsgemeinschaft, Grant/ Award Number: FR700/18-1 We thank Christopher Barnes (AGH University of Science and Technology, Kraków) for providing us with some of the studied samples. Kathrin Fassmer thanks Svenja Trapp and Matthias Hauke (University of Bonn) for help during Lu–Hf laboratory work. We would also like to thank M. Smit, F. Corfu and A. Kylander-Clark for their reviews which greatly contributed to improving the manuscript. This research was funded by DFG-Grant FR700/18-1 to N. F. and the Slovak Research and Development Agency project APVV-18- 0107 to M.J, and partially supported by the National Science Centre (Poland) project 2014/14/ST10/00321 to J. Majka. M.Bukała acknowledges The Polish National Agency for Academic Exchange for the scholarship no. PPN/ IWA/2018/1/00046/U/0001. This is contribution no. 64 of the DFG-funded LA-ICP- MS Laboratory at the Institute for Geosciences, University of Bonn, Germany. 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 Tsakkok Lenses. Eclogites occur in the Vaimok and Tsakkok 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 Tsakkok 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 Jamtland. Eclogites from the Vaimok (one sample) and Tsakkok (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 (Tsakkok). The ages from Tsakkok 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 Jamtland (c. 460-450 Ma) and Norrbotten (c. 488-480 Ma) may reflect the collision of an island arc with an irregularly shaped passive continental margin of Baltica or alternatively the collision of a straight margin with a microcontinent (Sarek Lens) accreted to the upper plate. Agentura na Podporu Vyskumu a Vyvoja APVV-18-0107 German Research Foundation (DFG) FR700/18-1 |
format |
Article in Journal/Newspaper |
author |
Fassmer, Kathrin Bukała, Michał |
author_facet |
Fassmer, Kathrin Bukała, Michał |
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 Publishing |
publishDate |
2021 |
url |
http://hdl.handle.net/10481/68383 https://doi.org/10.1111/jmg.12591 |
long_lat |
ENVELOPE(17.500,17.500,67.350,67.350) ENVELOPE(16.896,16.896,67.033,67.033) |
geographic |
Sarek Vaimok |
geographic_facet |
Sarek Vaimok |
genre |
North Sweden Norrbotten |
genre_facet |
North Sweden Norrbotten |
op_relation |
Fassmer, K, Froitzheim, N, Janák, M, et al. Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden). J Metamorph Geol. 2021; 00: 1– 24. [https://doi.org/10.1111/jmg.12591] http://hdl.handle.net/10481/68383 doi:10.1111/jmg.12591 |
op_rights |
Atribución-NoComercial 3.0 España http://creativecommons.org/licenses/by-nc/3.0/es/ info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY-NC |
op_doi |
https://doi.org/10.1111/jmg.12591 |
container_title |
Journal of Metamorphic Geology |
_version_ |
1766141215132090368 |
spelling |
ftunivgranada:oai:digibug.ugr.es:10481/68383 2023-05-15T17:40:20+02:00 Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden) Fassmer, Kathrin Bukała, Michał 2021-01-09 http://hdl.handle.net/10481/68383 https://doi.org/10.1111/jmg.12591 eng eng Wiley-Blackwell Publishing Fassmer, K, Froitzheim, N, Janák, M, et al. Diachronous collision in the Seve Nappe Complex: Evidence from Lu–Hf geochronology of eclogites (Norrbotten, North Sweden). J Metamorph Geol. 2021; 00: 1– 24. [https://doi.org/10.1111/jmg.12591] http://hdl.handle.net/10481/68383 doi:10.1111/jmg.12591 Atribución-NoComercial 3.0 España http://creativecommons.org/licenses/by-nc/3.0/es/ info:eu-repo/semantics/openAccess CC-BY-NC Caledonian Orogeny Garnet High‐P metamorphism Lu-Hf geochronology Seve Nappe Complex info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftunivgranada https://doi.org/10.1111/jmg.12591 2021-05-11T23:20:48Z Agentúra na Podporu Výskumu a Vývoja, Grant/Award Number: APVV-18- 0107; Deutsche Forschungsgemeinschaft, Grant/ Award Number: FR700/18-1 We thank Christopher Barnes (AGH University of Science and Technology, Kraków) for providing us with some of the studied samples. Kathrin Fassmer thanks Svenja Trapp and Matthias Hauke (University of Bonn) for help during Lu–Hf laboratory work. We would also like to thank M. Smit, F. Corfu and A. Kylander-Clark for their reviews which greatly contributed to improving the manuscript. This research was funded by DFG-Grant FR700/18-1 to N. F. and the Slovak Research and Development Agency project APVV-18- 0107 to M.J, and partially supported by the National Science Centre (Poland) project 2014/14/ST10/00321 to J. Majka. M.Bukała acknowledges The Polish National Agency for Academic Exchange for the scholarship no. PPN/ IWA/2018/1/00046/U/0001. This is contribution no. 64 of the DFG-funded LA-ICP- MS Laboratory at the Institute for Geosciences, University of Bonn, Germany. 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 Tsakkok Lenses. Eclogites occur in the Vaimok and Tsakkok 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 Tsakkok 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 Jamtland. Eclogites from the Vaimok (one sample) and Tsakkok (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 (Tsakkok). The ages from Tsakkok 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 Jamtland (c. 460-450 Ma) and Norrbotten (c. 488-480 Ma) may reflect the collision of an island arc with an irregularly shaped passive continental margin of Baltica or alternatively the collision of a straight margin with a microcontinent (Sarek Lens) accreted to the upper plate. Agentura na Podporu Vyskumu a Vyvoja APVV-18-0107 German Research Foundation (DFG) FR700/18-1 Article in Journal/Newspaper North Sweden Norrbotten DIGIBUG: Repositorio Institucional de la Universidad de Granada Sarek ENVELOPE(17.500,17.500,67.350,67.350) Vaimok ENVELOPE(16.896,16.896,67.033,67.033) Journal of Metamorphic Geology |