Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin
Abstract Structural analysis of the Lower Allochthon in the north-central Scandinavian Caledonides has allowed the construction of restorable cross-sections consistent with the development of a foreland-propagating linked thrust system. The internal geometry of an antiformal stack, the Njakafjäll du...
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Cambridge University Press (CUP)
1989
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Online Access: | http://dx.doi.org/10.1017/s0016756800022822 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800022822 |
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crcambridgeupr:10.1017/s0016756800022822 2024-03-03T08:43:22+00:00 Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin Gayer, Rodney A. Greiling, Reinhard O. 1989 http://dx.doi.org/10.1017/s0016756800022822 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800022822 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 126, issue 5, page 499-513 ISSN 0016-7568 1469-5081 Geology journal-article 1989 crcambridgeupr https://doi.org/10.1017/s0016756800022822 2024-02-08T08:40:06Z Abstract Structural analysis of the Lower Allochthon in the north-central Scandinavian Caledonides has allowed the construction of restorable cross-sections consistent with the development of a foreland-propagating linked thrust system. The internal geometry of an antiformal stack, the Njakafjäll duplex, within the Lower Allochthon demonstrates tectonic shortening of c. 50% and suggests an overall predeformational width for the Lower Allochthon in this area of at least c. 130 km, and possibly considerably greater if the buried trailing edge of the Lower Allochthon lies in a comparable position to that farther south in Tröndelag. These results, combined with a stratigraphic analysis of the imbricates within the Lower Allochthon and of the adjoining Autochthon and Middle Allochthon, indicate the development, from Proterozoic through Cambrian times, of two sedimentary basins on the c. 200 km wide continental margin of Baltica bordering the Iapetus Ocean. The basins were separated by a region of basement relief, the Børgefjell domain, above which a reduced sequence of Vendian to Cambrian rocks accumulated. This Børgefjell basement high, and the similar Njakafjäll basement high to the east, subsequently became the sites of antiformal stack development. It is argued that the frequent incorporation of basement into the thrust sheets, together with the thin sedimentary fill of these basins, compared with the much greater fill in basins to the south in Jämtland and to the north of Finnmark, implies major palaeogeographic changes along the Baltoscandian margin, possibly related to early rift geometries. The apparent lack of subsequent foreland basin development in north-central Scandinavia compared with areas to the south may indicate a deeper level of thrust detachment beneath the Middle Allochthon to the north, such that any foreland basin sediments have been removed in the hangingwall and subsequently eroded. An alternative possibility is a primary absence of foreland basin development that may relate to a differing ... Article in Journal/Newspaper Børgefjell Finnmark Finnmark Cambridge University Press Geological Magazine 126 5 499 513 |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Geology |
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Geology Gayer, Rodney A. Greiling, Reinhard O. Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin |
topic_facet |
Geology |
description |
Abstract Structural analysis of the Lower Allochthon in the north-central Scandinavian Caledonides has allowed the construction of restorable cross-sections consistent with the development of a foreland-propagating linked thrust system. The internal geometry of an antiformal stack, the Njakafjäll duplex, within the Lower Allochthon demonstrates tectonic shortening of c. 50% and suggests an overall predeformational width for the Lower Allochthon in this area of at least c. 130 km, and possibly considerably greater if the buried trailing edge of the Lower Allochthon lies in a comparable position to that farther south in Tröndelag. These results, combined with a stratigraphic analysis of the imbricates within the Lower Allochthon and of the adjoining Autochthon and Middle Allochthon, indicate the development, from Proterozoic through Cambrian times, of two sedimentary basins on the c. 200 km wide continental margin of Baltica bordering the Iapetus Ocean. The basins were separated by a region of basement relief, the Børgefjell domain, above which a reduced sequence of Vendian to Cambrian rocks accumulated. This Børgefjell basement high, and the similar Njakafjäll basement high to the east, subsequently became the sites of antiformal stack development. It is argued that the frequent incorporation of basement into the thrust sheets, together with the thin sedimentary fill of these basins, compared with the much greater fill in basins to the south in Jämtland and to the north of Finnmark, implies major palaeogeographic changes along the Baltoscandian margin, possibly related to early rift geometries. The apparent lack of subsequent foreland basin development in north-central Scandinavia compared with areas to the south may indicate a deeper level of thrust detachment beneath the Middle Allochthon to the north, such that any foreland basin sediments have been removed in the hangingwall and subsequently eroded. An alternative possibility is a primary absence of foreland basin development that may relate to a differing ... |
format |
Article in Journal/Newspaper |
author |
Gayer, Rodney A. Greiling, Reinhard O. |
author_facet |
Gayer, Rodney A. Greiling, Reinhard O. |
author_sort |
Gayer, Rodney A. |
title |
Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin |
title_short |
Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin |
title_full |
Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin |
title_fullStr |
Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin |
title_full_unstemmed |
Caledonian nappe geometry in north-central Sweden and basin evolution on the Baltoscandian margin |
title_sort |
caledonian nappe geometry in north-central sweden and basin evolution on the baltoscandian margin |
publisher |
Cambridge University Press (CUP) |
publishDate |
1989 |
url |
http://dx.doi.org/10.1017/s0016756800022822 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800022822 |
genre |
Børgefjell Finnmark Finnmark |
genre_facet |
Børgefjell Finnmark Finnmark |
op_source |
Geological Magazine volume 126, issue 5, page 499-513 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756800022822 |
container_title |
Geological Magazine |
container_volume |
126 |
container_issue |
5 |
container_start_page |
499 |
op_container_end_page |
513 |
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1792498799693791232 |