Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea
In northern Norway, late/post-Caledonian extension initiated along inverted, brittle-ductile thrusts, e.g. Sørøya-Ingøya shear zone, which truncated existing, margin-oblique, late Neoproterozoic, Timanian faults and margin-parallel, latest Mesoproterozoic-mid Neoproterozoic faults related to the ope...
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UiT Norges arktiske universitet
2018
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ftunivtroemsoe:oai:munin.uit.no:10037/13021 2023-05-15T15:39:12+02:00 Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea Koehl, Jean-Baptiste Philippe 2018-05-24 https://hdl.handle.net/10037/13021 eng eng UiT Norges arktiske universitet UiT The Arctic University of Norway 978-82-8236-298-6 (trykt) og 978-82-8236-299-3 (pdf) https://hdl.handle.net/10037/13021 openAccess Copyright 2018 The Author(s) VDP::Mathematics and natural science: 400::Geosciences: 450::Tectonics: 463 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Tektonikk: 463 DOKTOR-004 Doctoral thesis Doktorgradsavhandling 2018 ftunivtroemsoe 2021-06-25T17:55:56Z In northern Norway, late/post-Caledonian extension initiated along inverted, brittle-ductile thrusts, e.g. Sørøya-Ingøya shear zone, which truncated existing, margin-oblique, late Neoproterozoic, Timanian faults and margin-parallel, latest Mesoproterozoic-mid Neoproterozoic faults related to the opening of the Asgard Sea and Iapetus Ocean. Inverted thrusts were active through the Devonian and early Carboniferous, accommodating the deposition of thick, Mid/Upper Devonian growth strata and of subsequent, lower Carboniferous sedimentary rocks in spoon-shaped basins on the Finnmark Platform and in the southwesternmost Nordkapp basin. Simultaneously, NE-SW trending basement ridges exhumed as part of a regional metamorphic core complex along bowed portions of the Sørøya-Ingøya shear zone and in the footwall of high-angle, zigzag-shaped normal faults following pre-existing basement fabrics, such as the Troms-Finnmark Fault Complex. Late/post-Caledonian exhumation is also documented onshore adjacent areas in NW Finnmark by retrograde fault-rock mineral assemblages and K/Ar faulting ages along the Langfjord-Vargsund fault, indicating rapid exhumation from > 10 km to 2-8 km depth in the Late Devonian-early Carboniferous. Inherited, margin-oblique brittle faults such as the Trollfjorden-Komagelva Fault Zone acted as minor strike-slip transfer faults, segmenting the margin and offsetting major zigzag-shaped fault complexes like the Langfjord-Vargsund fault. Bathymetry data further show sigma-shaped mini-basins with dense, internal, fault-fracture networks (e.g. Ryggefjorden trough), potentially representing small-scale analogs to major offshore basins such as the Nordkapp Basin. In the late Carboniferous, faulting activity declined and extension localized along a few major faults. In addition, Caledonian rocks were slowly exhumed to depths < 3.5 km., and thick, upper Carboniferous evaporites deposited in the southwesternmost Nordkapp basin. The margin was tectonically quiet by the end of the Carboniferous and was only subjected to minor, Permian-Cenozoic tectonic adjustments. Alternatively, late Carboniferous-mid Permian K/Ar ages obtained in NW Finnmark reflect an episode of margin weathering. Doctoral or Postdoctoral Thesis Barents Sea Finnmark Ingøya Nordkapp Nordkapp Basin Northern Norway Sørøya Finnmark Troms University of Tromsø: Munin Open Research Archive Barents Sea Komagelva ENVELOPE(30.528,30.528,70.241,70.241) Langfjord ENVELOPE(22.363,22.363,70.056,70.056) Norway Sørøya ENVELOPE(7.942,7.942,63.352,63.352) |
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::Tectonics: 463 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Tektonikk: 463 DOKTOR-004 |
spellingShingle |
VDP::Mathematics and natural science: 400::Geosciences: 450::Tectonics: 463 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Tektonikk: 463 DOKTOR-004 Koehl, Jean-Baptiste Philippe Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea |
topic_facet |
VDP::Mathematics and natural science: 400::Geosciences: 450::Tectonics: 463 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Tektonikk: 463 DOKTOR-004 |
description |
In northern Norway, late/post-Caledonian extension initiated along inverted, brittle-ductile thrusts, e.g. Sørøya-Ingøya shear zone, which truncated existing, margin-oblique, late Neoproterozoic, Timanian faults and margin-parallel, latest Mesoproterozoic-mid Neoproterozoic faults related to the opening of the Asgard Sea and Iapetus Ocean. Inverted thrusts were active through the Devonian and early Carboniferous, accommodating the deposition of thick, Mid/Upper Devonian growth strata and of subsequent, lower Carboniferous sedimentary rocks in spoon-shaped basins on the Finnmark Platform and in the southwesternmost Nordkapp basin. Simultaneously, NE-SW trending basement ridges exhumed as part of a regional metamorphic core complex along bowed portions of the Sørøya-Ingøya shear zone and in the footwall of high-angle, zigzag-shaped normal faults following pre-existing basement fabrics, such as the Troms-Finnmark Fault Complex. Late/post-Caledonian exhumation is also documented onshore adjacent areas in NW Finnmark by retrograde fault-rock mineral assemblages and K/Ar faulting ages along the Langfjord-Vargsund fault, indicating rapid exhumation from > 10 km to 2-8 km depth in the Late Devonian-early Carboniferous. Inherited, margin-oblique brittle faults such as the Trollfjorden-Komagelva Fault Zone acted as minor strike-slip transfer faults, segmenting the margin and offsetting major zigzag-shaped fault complexes like the Langfjord-Vargsund fault. Bathymetry data further show sigma-shaped mini-basins with dense, internal, fault-fracture networks (e.g. Ryggefjorden trough), potentially representing small-scale analogs to major offshore basins such as the Nordkapp Basin. In the late Carboniferous, faulting activity declined and extension localized along a few major faults. In addition, Caledonian rocks were slowly exhumed to depths < 3.5 km., and thick, upper Carboniferous evaporites deposited in the southwesternmost Nordkapp basin. The margin was tectonically quiet by the end of the Carboniferous and was only subjected to minor, Permian-Cenozoic tectonic adjustments. Alternatively, late Carboniferous-mid Permian K/Ar ages obtained in NW Finnmark reflect an episode of margin weathering. |
format |
Doctoral or Postdoctoral Thesis |
author |
Koehl, Jean-Baptiste Philippe |
author_facet |
Koehl, Jean-Baptiste Philippe |
author_sort |
Koehl, Jean-Baptiste Philippe |
title |
Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea |
title_short |
Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea |
title_full |
Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea |
title_fullStr |
Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea |
title_full_unstemmed |
Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea |
title_sort |
mid/late devonian-carboniferous extensional faulting in finnmark and the sw barents sea |
publisher |
UiT Norges arktiske universitet |
publishDate |
2018 |
url |
https://hdl.handle.net/10037/13021 |
long_lat |
ENVELOPE(30.528,30.528,70.241,70.241) ENVELOPE(22.363,22.363,70.056,70.056) ENVELOPE(7.942,7.942,63.352,63.352) |
geographic |
Barents Sea Komagelva Langfjord Norway Sørøya |
geographic_facet |
Barents Sea Komagelva Langfjord Norway Sørøya |
genre |
Barents Sea Finnmark Ingøya Nordkapp Nordkapp Basin Northern Norway Sørøya Finnmark Troms |
genre_facet |
Barents Sea Finnmark Ingøya Nordkapp Nordkapp Basin Northern Norway Sørøya Finnmark Troms |
op_relation |
978-82-8236-298-6 (trykt) og 978-82-8236-299-3 (pdf) https://hdl.handle.net/10037/13021 |
op_rights |
openAccess Copyright 2018 The Author(s) |
_version_ |
1766370665191964672 |