Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark
In the SW Barents Sea, Devonian–Carboniferous collapse led to the formation of major basins and faults, e.g., the Hammerfest Basin bounded by the Troms–Finnmark Fault Complex, and rhomboid- to sigma-shaped (half-)grabens on the Finnmark Platform. High-resolution aeromagnetic and bathymetry data from...
Published in: | Norwegian Journal of Geology |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Geological Society of Norway
2019
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Online Access: | https://hdl.handle.net/10037/18392 https://doi.org/10.17850/njg99-3-5 |
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ftunivtroemsoe:oai:munin.uit.no:10037/18392 2023-05-15T14:23:50+02:00 Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark Koehl, Jean-Baptiste P. Bergh, Steffen G Osmundsen, Per Terje Redfield, Thomas Fitzmaurice Indrevær, Kjetil Lea, Halldis Bergø, Espen 2019-09-10 https://hdl.handle.net/10037/18392 https://doi.org/10.17850/njg99-3-5 eng eng Geological Society of Norway Norwegian Journal of Geology info:eu-repo/grantAgreement/RCN/PETROSENTR/228107/Norway/Research Centre for Arctic Petroleum Exploration/ARCEx/ FRIDAID 1738102 doi:10.17850/njg99-3-5 2387-5844 2387-5852 https://hdl.handle.net/10037/18392 openAccess Copyright 2019 The Authors VDP::Mathematics and natural science: 400::Geosciences: 450::Stratigraphy and paleontology: 461 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Stratigrafi og paleontologi: 461 Journal article Tidsskriftartikkel Peer reviewed publishedVersion 2019 ftunivtroemsoe https://doi.org/10.17850/njg99-3-5 2021-06-25T17:56:52Z In the SW Barents Sea, Devonian–Carboniferous collapse led to the formation of major basins and faults, e.g., the Hammerfest Basin bounded by the Troms–Finnmark Fault Complex, and rhomboid- to sigma-shaped (half-)grabens on the Finnmark Platform. High-resolution aeromagnetic and bathymetry data from the shallow shelf show that analogue fault systems are present in coastal and onshore areas of NW Finnmark. We provide new documentation for the Langfjorden–Vargsundet fault, a post-Caledonian, NW-dipping, zigzag-shaped, margin-parallel fault complex consisting of alternating linear to sub-linear, NNE–SSW- and ENE–WSW-striking, down-NW normal fault segments. This fault formed as an extensional splay-fault of inverted, Caledonian, brittle–ductile thrusts, e.g, the Talvik and Kvenklubben faults, which the fault eventually truncated and offset. In northern Finnmark, the Langfjorden–Vargsundet fault is offset laterally by up to 28 km by a system of WNW–ESE-trending faults notably including potential segments and splays of the Trollfjorden–Komagelva Fault Zone, a reactivated Neoproterozoic, margin-orthogonal transfer fault, separating NW Finnmark from the eastern Finnmark Platform. This fault system likely dies out westwards, and portions of the system’s process zone may crop out on the island of Magerøya. Similarly, the WNW–ESE- to ENE–WSW-striking Akkarfjord fault offsets the Langfjorden–Vargsundet fault by c. 2 km left-laterally. This fault may have formed as a conjugate to the Trollfjorden–Komagelva Fault Zone in Neoproterozoic (Timanian?) times. Steeply NW-plunging, upright and gently NE-plunging, inclined folds in Archaean–Palaeoproterozoic basement rocks and margin-parallel Caledonian thrusts may have controlled the formation and geometry of post-Caledonian faults. A Late Devonian–Carboniferous age for the Langfjorden–Vargsundet fault is supported by geochronological dating of onshore dykes and fault gouge, and by syn-tectonic sedimentary wedges along the offshore extension of the Langfjorden–Vargsundet fault. Mini-basins bounded by the Langfjorden– Vargsundet fault on the Finnmark Platform and on the shallow shelf, e.g., the Ryggefjorden trough, may represent analogues to deep, offshore, Devonian–Carboniferous basins, like the Nordkapp Basin, prior to the deposition of late Palaeozoic evaporites. Article in Journal/Newspaper Arctic Barents Sea Finnmark Hammerfest Hammerfest Basin Magerøya Nordkapp Nordkapp Basin Finnmark Troms University of Tromsø: Munin Open Research Archive Barents Sea Komagelva ENVELOPE(30.528,30.528,70.241,70.241) Kvenklubben ENVELOPE(23.637,23.637,70.405,70.405) Langfjorden ENVELOPE(12.676,12.676,65.378,65.378) Talvik ENVELOPE(22.949,22.949,70.042,70.042) Norwegian Journal of Geology |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Mathematics and natural science: 400::Geosciences: 450::Stratigraphy and paleontology: 461 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Stratigrafi og paleontologi: 461 |
spellingShingle |
VDP::Mathematics and natural science: 400::Geosciences: 450::Stratigraphy and paleontology: 461 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Stratigrafi og paleontologi: 461 Koehl, Jean-Baptiste P. Bergh, Steffen G Osmundsen, Per Terje Redfield, Thomas Fitzmaurice Indrevær, Kjetil Lea, Halldis Bergø, Espen Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark |
topic_facet |
VDP::Mathematics and natural science: 400::Geosciences: 450::Stratigraphy and paleontology: 461 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Stratigrafi og paleontologi: 461 |
description |
In the SW Barents Sea, Devonian–Carboniferous collapse led to the formation of major basins and faults, e.g., the Hammerfest Basin bounded by the Troms–Finnmark Fault Complex, and rhomboid- to sigma-shaped (half-)grabens on the Finnmark Platform. High-resolution aeromagnetic and bathymetry data from the shallow shelf show that analogue fault systems are present in coastal and onshore areas of NW Finnmark. We provide new documentation for the Langfjorden–Vargsundet fault, a post-Caledonian, NW-dipping, zigzag-shaped, margin-parallel fault complex consisting of alternating linear to sub-linear, NNE–SSW- and ENE–WSW-striking, down-NW normal fault segments. This fault formed as an extensional splay-fault of inverted, Caledonian, brittle–ductile thrusts, e.g, the Talvik and Kvenklubben faults, which the fault eventually truncated and offset. In northern Finnmark, the Langfjorden–Vargsundet fault is offset laterally by up to 28 km by a system of WNW–ESE-trending faults notably including potential segments and splays of the Trollfjorden–Komagelva Fault Zone, a reactivated Neoproterozoic, margin-orthogonal transfer fault, separating NW Finnmark from the eastern Finnmark Platform. This fault system likely dies out westwards, and portions of the system’s process zone may crop out on the island of Magerøya. Similarly, the WNW–ESE- to ENE–WSW-striking Akkarfjord fault offsets the Langfjorden–Vargsundet fault by c. 2 km left-laterally. This fault may have formed as a conjugate to the Trollfjorden–Komagelva Fault Zone in Neoproterozoic (Timanian?) times. Steeply NW-plunging, upright and gently NE-plunging, inclined folds in Archaean–Palaeoproterozoic basement rocks and margin-parallel Caledonian thrusts may have controlled the formation and geometry of post-Caledonian faults. A Late Devonian–Carboniferous age for the Langfjorden–Vargsundet fault is supported by geochronological dating of onshore dykes and fault gouge, and by syn-tectonic sedimentary wedges along the offshore extension of the Langfjorden–Vargsundet fault. Mini-basins bounded by the Langfjorden– Vargsundet fault on the Finnmark Platform and on the shallow shelf, e.g., the Ryggefjorden trough, may represent analogues to deep, offshore, Devonian–Carboniferous basins, like the Nordkapp Basin, prior to the deposition of late Palaeozoic evaporites. |
format |
Article in Journal/Newspaper |
author |
Koehl, Jean-Baptiste P. Bergh, Steffen G Osmundsen, Per Terje Redfield, Thomas Fitzmaurice Indrevær, Kjetil Lea, Halldis Bergø, Espen |
author_facet |
Koehl, Jean-Baptiste P. Bergh, Steffen G Osmundsen, Per Terje Redfield, Thomas Fitzmaurice Indrevær, Kjetil Lea, Halldis Bergø, Espen |
author_sort |
Koehl, Jean-Baptiste P. |
title |
Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark |
title_short |
Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark |
title_full |
Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark |
title_fullStr |
Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark |
title_full_unstemmed |
Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark |
title_sort |
late devonian–carboniferous faulting and controlling structures and fabrics in nw finnmark |
publisher |
Geological Society of Norway |
publishDate |
2019 |
url |
https://hdl.handle.net/10037/18392 https://doi.org/10.17850/njg99-3-5 |
long_lat |
ENVELOPE(30.528,30.528,70.241,70.241) ENVELOPE(23.637,23.637,70.405,70.405) ENVELOPE(12.676,12.676,65.378,65.378) ENVELOPE(22.949,22.949,70.042,70.042) |
geographic |
Barents Sea Komagelva Kvenklubben Langfjorden Talvik |
geographic_facet |
Barents Sea Komagelva Kvenklubben Langfjorden Talvik |
genre |
Arctic Barents Sea Finnmark Hammerfest Hammerfest Basin Magerøya Nordkapp Nordkapp Basin Finnmark Troms |
genre_facet |
Arctic Barents Sea Finnmark Hammerfest Hammerfest Basin Magerøya Nordkapp Nordkapp Basin Finnmark Troms |
op_relation |
Norwegian Journal of Geology info:eu-repo/grantAgreement/RCN/PETROSENTR/228107/Norway/Research Centre for Arctic Petroleum Exploration/ARCEx/ FRIDAID 1738102 doi:10.17850/njg99-3-5 2387-5844 2387-5852 https://hdl.handle.net/10037/18392 |
op_rights |
openAccess Copyright 2019 The Authors |
op_doi |
https://doi.org/10.17850/njg99-3-5 |
container_title |
Norwegian Journal of Geology |
_version_ |
1766296311246618624 |