Restoration of the external Scandinavian Caledonides
Abstract Three models are evaluated for restoring basement rocks coring tectonic windows (Window-Basement) in the Scandinavian Caledonides; parautochthonous (Model I) and allochthonous (models II/III), with initial imbrication of the Window-Basement post-dating or pre-dating, respectively, that in t...
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crcambridgeupr:10.1017/s0016756816000340 2024-03-03T08:44:21+00:00 Restoration of the external Scandinavian Caledonides RICE, A. HUGH N. ANDERSON, MARK W. 2016 http://dx.doi.org/10.1017/s0016756816000340 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756816000340 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 153, issue 5-6, page 1136-1165 ISSN 0016-7568 1469-5081 Geology journal-article 2016 crcambridgeupr https://doi.org/10.1017/s0016756816000340 2024-02-08T08:37:02Z Abstract Three models are evaluated for restoring basement rocks coring tectonic windows (Window-Basement) in the Scandinavian Caledonides; parautochthonous (Model I) and allochthonous (models II/III), with initial imbrication of the Window-Basement post-dating or pre-dating, respectively, that in the external imbricate zone (Lower Allochthon). In Model I, the Window-Basement comes from the eastern margin of the basin now imbricated into the Lower Allochthon, while in models II/III it comes from the western margin. In Model II, the Window-Basement formed a basement-high between Tonian and Cryogenian sediments imbricated into the Middle and Lower allochthons; in Model III deposition of the Lower Allochthon sediments commenced in Ediacaran times. Balanced cross-sections and branch-line restorations of four transects (Finnmark–Troms, Västerbotten–Nordland, Jämtland–Trøndelag, Telemark–Møre og Romsdal) show similar restored lengths for the models in two transects and longer restorations for models II/III in the other transects. Model I can result in c. 280 km wide gaps in the restored Lower Allochthon, evidence for which is not seen in the sedimentology. The presence of <3 km thick alluvial-fan deposits at the base of the Middle Allochthon indicates proximal, rapidly uplifting basement during Tonian–Cryogenian periods, taken as the origin of the Window-Basement during thrusting in models II/III. Model I requires multiple changes in thrusting-direction and predicts major thrusts or back-thrusts, currently unrecognized, separating parts of the Lower Allochthon; neither are required in models II/III. Metamorphic data are consistent with models II/III. Despite considerable along-strike structural variability in the external Scandinavian Caledonides, models II/III are preferred for the restoration of the Window-Basement. Article in Journal/Newspaper Finnmark Nordland Nordland Finnmark Nordland Troms Cambridge University Press Geological Magazine 153 5-6 1136 1165 |
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Geology |
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Geology RICE, A. HUGH N. ANDERSON, MARK W. Restoration of the external Scandinavian Caledonides |
topic_facet |
Geology |
description |
Abstract Three models are evaluated for restoring basement rocks coring tectonic windows (Window-Basement) in the Scandinavian Caledonides; parautochthonous (Model I) and allochthonous (models II/III), with initial imbrication of the Window-Basement post-dating or pre-dating, respectively, that in the external imbricate zone (Lower Allochthon). In Model I, the Window-Basement comes from the eastern margin of the basin now imbricated into the Lower Allochthon, while in models II/III it comes from the western margin. In Model II, the Window-Basement formed a basement-high between Tonian and Cryogenian sediments imbricated into the Middle and Lower allochthons; in Model III deposition of the Lower Allochthon sediments commenced in Ediacaran times. Balanced cross-sections and branch-line restorations of four transects (Finnmark–Troms, Västerbotten–Nordland, Jämtland–Trøndelag, Telemark–Møre og Romsdal) show similar restored lengths for the models in two transects and longer restorations for models II/III in the other transects. Model I can result in c. 280 km wide gaps in the restored Lower Allochthon, evidence for which is not seen in the sedimentology. The presence of <3 km thick alluvial-fan deposits at the base of the Middle Allochthon indicates proximal, rapidly uplifting basement during Tonian–Cryogenian periods, taken as the origin of the Window-Basement during thrusting in models II/III. Model I requires multiple changes in thrusting-direction and predicts major thrusts or back-thrusts, currently unrecognized, separating parts of the Lower Allochthon; neither are required in models II/III. Metamorphic data are consistent with models II/III. Despite considerable along-strike structural variability in the external Scandinavian Caledonides, models II/III are preferred for the restoration of the Window-Basement. |
format |
Article in Journal/Newspaper |
author |
RICE, A. HUGH N. ANDERSON, MARK W. |
author_facet |
RICE, A. HUGH N. ANDERSON, MARK W. |
author_sort |
RICE, A. HUGH N. |
title |
Restoration of the external Scandinavian Caledonides |
title_short |
Restoration of the external Scandinavian Caledonides |
title_full |
Restoration of the external Scandinavian Caledonides |
title_fullStr |
Restoration of the external Scandinavian Caledonides |
title_full_unstemmed |
Restoration of the external Scandinavian Caledonides |
title_sort |
restoration of the external scandinavian caledonides |
publisher |
Cambridge University Press (CUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1017/s0016756816000340 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756816000340 |
genre |
Finnmark Nordland Nordland Finnmark Nordland Troms |
genre_facet |
Finnmark Nordland Nordland Finnmark Nordland Troms |
op_source |
Geological Magazine volume 153, issue 5-6, page 1136-1165 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756816000340 |
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Geological Magazine |
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153 |
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5-6 |
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1136 |
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1165 |
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1792499834960216064 |