The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia
The Sveconorwegian orogeny encompasses magmatic, metamorphic and deformational events between ca. 1140 and 920 Ma at the southwestern margin of Fennoscandia. In recent years, the tectonic setting of this nearly 200 Myr-long evolution has been debated, with some workers arguing for collision with an...
Published in: | Precambrian Research |
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Main Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
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2020
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Online Access: | http://hdl.handle.net/10852/81098 http://urn.nb.no/URN:NBN:no-84183 https://doi.org/10.1016/j.precamres.2020.105877 |
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Open Polar |
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Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
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ftoslouniv |
language |
English |
description |
The Sveconorwegian orogeny encompasses magmatic, metamorphic and deformational events between ca. 1140 and 920 Ma at the southwestern margin of Fennoscandia. In recent years, the tectonic setting of this nearly 200 Myr-long evolution has been debated, with some workers arguing for collision with an unknown continent off the present-day southwest coast of Norway, and others advocating accretionary processes inboard of an active margin. Recently, it has been suggested that orogeny may have been gravity-driven by delamination and foundering of heavy subcontinental lithospheric mantle in an intraplate setting, in some ways similar to proposed sagduction processes in the Archaean. Resolving the tectonic setting of the Sveconorwegian orogen has implications for correlation with other orogens and Rodinia supercontinent reconstructions and for assessments of the evolution of plate tectonics on Earth, from the Archaean to the present. Here, we present new mapping and geochronological data from the Bamble and Telemark lithotectonic units in the central and western Sveconorwegian orogen – the former representing a critical region separating western parts of the orogen that underwent long-lived high- to ultrahigh-temperature metamorphism and magmatism from parts closer to the orogenic foreland that underwent episodic high-pressure events. The data show that the units constituting the Sveconorwegian orogen most likely formed at the southwestern margin of Fennoscandia between ca. 1800 and 1480 Ma, followed by fragmentation during widespread extension between ca. 1340 and 1100 Ma marked by bimodal magmatism and sedimentation. A summary of Sveconorwegian magmatic, metamorphic and depositional events in the different units shows disparate histories prior to their assembly with adjacent units. The most likely interpretation of this record seems to be that episodic, Sveconorwegian metamorphic and deformational events in the central and eastern parts of the orogen represent accretion and assembly of these units. This process most likely took place behind an active margin to the southwest that sustained mafic underplating in the proximal back-arc, resulting in high- to ultrahigh-temperature metamorphism in the western parts. In this interpretation, all features of the Sveconorwegian orogen are readily explained by modern-style plate tectonic processes and hypotheses involving some form of vertical, intraplate tectonics are not supported. |
format |
Article in Journal/Newspaper |
author |
Slagstad, Trond Marker, Mogens Roberts, Nick M.W. Saalmann, Kerstin Kirkland, Christopher L. Kulakov, Evgeniy Ganerød, Morgan Røhr, Torkil Sørlie Møkkelgjerd, Steinar Halvdan Hansen Granseth, Anette Sørensen, Bjørn Eske |
spellingShingle |
Slagstad, Trond Marker, Mogens Roberts, Nick M.W. Saalmann, Kerstin Kirkland, Christopher L. Kulakov, Evgeniy Ganerød, Morgan Røhr, Torkil Sørlie Møkkelgjerd, Steinar Halvdan Hansen Granseth, Anette Sørensen, Bjørn Eske The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia |
author_facet |
Slagstad, Trond Marker, Mogens Roberts, Nick M.W. Saalmann, Kerstin Kirkland, Christopher L. Kulakov, Evgeniy Ganerød, Morgan Røhr, Torkil Sørlie Møkkelgjerd, Steinar Halvdan Hansen Granseth, Anette Sørensen, Bjørn Eske |
author_sort |
Slagstad, Trond |
title |
The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia |
title_short |
The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia |
title_full |
The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia |
title_fullStr |
The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia |
title_full_unstemmed |
The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia |
title_sort |
sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of fennoscandia |
publishDate |
2020 |
url |
http://hdl.handle.net/10852/81098 http://urn.nb.no/URN:NBN:no-84183 https://doi.org/10.1016/j.precamres.2020.105877 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Fennoscandia |
genre_facet |
Fennoscandia |
op_source |
0301-9268 |
op_relation |
http://urn.nb.no/URN:NBN:no-84183 Slagstad, Trond Marker, Mogens Roberts, Nick M.W. Saalmann, Kerstin Kirkland, Christopher L. Kulakov, Evgeniy Ganerød, Morgan Røhr, Torkil Sørlie Møkkelgjerd, Steinar Halvdan Hansen Granseth, Anette Sørensen, Bjørn Eske . The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia. Precambrian Research. 2020, 350 http://hdl.handle.net/10852/81098 1822384 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Precambrian Research&rft.volume=350&rft.spage=&rft.date=2020 Precambrian Research 350 25 https://doi.org/10.1016/j.precamres.2020.105877 URN:NBN:no-84183 Fulltext https://www.duo.uio.no/bitstream/handle/10852/81098/2/precambrianresearch.pdf |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.precamres.2020.105877 |
container_title |
Precambrian Research |
container_volume |
350 |
container_start_page |
105877 |
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1765996879659663360 |
spelling |
ftoslouniv:oai:www.duo.uio.no:10852/81098 2023-05-15T16:11:43+02:00 The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia Slagstad, Trond Marker, Mogens Roberts, Nick M.W. Saalmann, Kerstin Kirkland, Christopher L. Kulakov, Evgeniy Ganerød, Morgan Røhr, Torkil Sørlie Møkkelgjerd, Steinar Halvdan Hansen Granseth, Anette Sørensen, Bjørn Eske 2020-08-10T11:53:12Z http://hdl.handle.net/10852/81098 http://urn.nb.no/URN:NBN:no-84183 https://doi.org/10.1016/j.precamres.2020.105877 EN eng http://urn.nb.no/URN:NBN:no-84183 Slagstad, Trond Marker, Mogens Roberts, Nick M.W. Saalmann, Kerstin Kirkland, Christopher L. Kulakov, Evgeniy Ganerød, Morgan Røhr, Torkil Sørlie Møkkelgjerd, Steinar Halvdan Hansen Granseth, Anette Sørensen, Bjørn Eske . The Sveconorwegian orogeny – reamalgamation of the fragmented southwestern margin of Fennoscandia. Precambrian Research. 2020, 350 http://hdl.handle.net/10852/81098 1822384 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Precambrian Research&rft.volume=350&rft.spage=&rft.date=2020 Precambrian Research 350 25 https://doi.org/10.1016/j.precamres.2020.105877 URN:NBN:no-84183 Fulltext https://www.duo.uio.no/bitstream/handle/10852/81098/2/precambrianresearch.pdf Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ CC-BY 0301-9268 Journal article Tidsskriftartikkel Peer reviewed PublishedVersion 2020 ftoslouniv https://doi.org/10.1016/j.precamres.2020.105877 2020-11-25T23:30:30Z The Sveconorwegian orogeny encompasses magmatic, metamorphic and deformational events between ca. 1140 and 920 Ma at the southwestern margin of Fennoscandia. In recent years, the tectonic setting of this nearly 200 Myr-long evolution has been debated, with some workers arguing for collision with an unknown continent off the present-day southwest coast of Norway, and others advocating accretionary processes inboard of an active margin. Recently, it has been suggested that orogeny may have been gravity-driven by delamination and foundering of heavy subcontinental lithospheric mantle in an intraplate setting, in some ways similar to proposed sagduction processes in the Archaean. Resolving the tectonic setting of the Sveconorwegian orogen has implications for correlation with other orogens and Rodinia supercontinent reconstructions and for assessments of the evolution of plate tectonics on Earth, from the Archaean to the present. Here, we present new mapping and geochronological data from the Bamble and Telemark lithotectonic units in the central and western Sveconorwegian orogen – the former representing a critical region separating western parts of the orogen that underwent long-lived high- to ultrahigh-temperature metamorphism and magmatism from parts closer to the orogenic foreland that underwent episodic high-pressure events. The data show that the units constituting the Sveconorwegian orogen most likely formed at the southwestern margin of Fennoscandia between ca. 1800 and 1480 Ma, followed by fragmentation during widespread extension between ca. 1340 and 1100 Ma marked by bimodal magmatism and sedimentation. A summary of Sveconorwegian magmatic, metamorphic and depositional events in the different units shows disparate histories prior to their assembly with adjacent units. The most likely interpretation of this record seems to be that episodic, Sveconorwegian metamorphic and deformational events in the central and eastern parts of the orogen represent accretion and assembly of these units. This process most likely took place behind an active margin to the southwest that sustained mafic underplating in the proximal back-arc, resulting in high- to ultrahigh-temperature metamorphism in the western parts. In this interpretation, all features of the Sveconorwegian orogen are readily explained by modern-style plate tectonic processes and hypotheses involving some form of vertical, intraplate tectonics are not supported. Article in Journal/Newspaper Fennoscandia Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Norway Precambrian Research 350 105877 |