Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard
Background The Billefjorden area in central Spitsbergen hosts thick Lower–lowermost Upper Devonian, late–post-Caledonian collapse deposits presumably deformed during the Late Devonian Svalbardian Orogeny. These rocks are juxtaposed against Proterozoic basement rocks along the Billefjorden Fault Zone...
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ftopenresearcheu:oai:oaipmh.f1000.com:10.12688/13165 2023-12-17T10:27:52+01:00 Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard Koehl, Jean-Baptiste P. Allaart, Lis Noormets, Riko text/html https://doi.org/10.12688/openreseurope.15936.2 eng eng F1000 Research Limited https://doi.org/10.12688/openreseurope.15936.1 https://doi.org/10.12688/openreseurope.15936.2 open access Open Research Europe 2023 3:124 Svalbard;Billefjorden;Devonian;décollement;Timanian;Svalbardian;Eurekan;Cenozoic text ftopenresearcheu https://doi.org/10.12688/openreseurope.15936.210.12688/openreseurope.15936.1 2023-11-22T00:02:33Z Background The Billefjorden area in central Spitsbergen hosts thick Lower–lowermost Upper Devonian, late–post-Caledonian collapse deposits presumably deformed during the Late Devonian Svalbardian Orogeny. These rocks are juxtaposed against Proterozoic basement rocks along the Billefjorden Fault Zone and are overlain by uppermost Devonian–early Permian deposits of the Billefjorden Trough, a N–S-trending Carboniferous rift basin bounded by the Billefjorden Fault Zone. Methods We interpreted seismic reflection (also depth-converted), bathymetric, and exploration well data. Results The data show abundant Early Devonian, WNW–ESE-striking (oblique-slip) normal faults segmenting the Billefjorden Trough, and a gradual decrease in tectonic activity from the Early Devonian (collapse phase) to early Permian (post-rift phase). Early Devonian–Middle Pennsylvanian WNW–ESE-striking faults were mildly reactivated and overprinted and accommodated strain partitioning and decoupling in the early Cenozoic. This resulted in intense deformation of Lower Devonian sedimentary rocks and in the formation of bedding-parallel décollements, e.g., between the Lower Devonian Wood Bay and the uppermost Pennsylvanian–lowermost Permian Wordiekammen formations. This suggests that intense deformation within Devonian rocks in Dickson Land can be explained by Eurekan deformation alone. Eurekan deformation also resulted in the formation of WNW–ESE- and N–S- to NNE–SSW-trending, kilometer-wide, open folds such as the Petuniabukta Syncline, and in inversion and/or overprinting of Early Devonian to Early Pennsylvanian normal faults by sinistral-reverse Eurekan thrusts. WNW–ESE-striking faults merge at depth with similarly trending and dipping ductile shear zone fabrics in Proterozoic basement rocks, which likely formed during the Timanian Orogeny. Conclusions A NNE-dipping shear zone, which is part of a large system of Timanian thrusts in the Barents Sea, controlled the formation of WNW–ESE-striking Devonian–Mississippian normal faults and syn-tectonic ... Text Barents Sea Billefjorden Dickson Land Svalbard Spitsbergen Open Research Europe Barents Sea Billefjorden ENVELOPE(16.417,16.417,78.563,78.563) Dickson Land ENVELOPE(16.000,16.000,78.667,78.667) Petuniabukta ENVELOPE(16.532,16.532,78.687,78.687) Svalbard Wood Bay ENVELOPE(165.500,165.500,-74.217,-74.217) Wordiekammen ENVELOPE(16.756,16.756,78.697,78.697) |
institution |
Open Polar |
collection |
Open Research Europe |
op_collection_id |
ftopenresearcheu |
language |
English |
topic |
Svalbard;Billefjorden;Devonian;décollement;Timanian;Svalbardian;Eurekan;Cenozoic |
spellingShingle |
Svalbard;Billefjorden;Devonian;décollement;Timanian;Svalbardian;Eurekan;Cenozoic Koehl, Jean-Baptiste P. Allaart, Lis Noormets, Riko Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard |
topic_facet |
Svalbard;Billefjorden;Devonian;décollement;Timanian;Svalbardian;Eurekan;Cenozoic |
description |
Background The Billefjorden area in central Spitsbergen hosts thick Lower–lowermost Upper Devonian, late–post-Caledonian collapse deposits presumably deformed during the Late Devonian Svalbardian Orogeny. These rocks are juxtaposed against Proterozoic basement rocks along the Billefjorden Fault Zone and are overlain by uppermost Devonian–early Permian deposits of the Billefjorden Trough, a N–S-trending Carboniferous rift basin bounded by the Billefjorden Fault Zone. Methods We interpreted seismic reflection (also depth-converted), bathymetric, and exploration well data. Results The data show abundant Early Devonian, WNW–ESE-striking (oblique-slip) normal faults segmenting the Billefjorden Trough, and a gradual decrease in tectonic activity from the Early Devonian (collapse phase) to early Permian (post-rift phase). Early Devonian–Middle Pennsylvanian WNW–ESE-striking faults were mildly reactivated and overprinted and accommodated strain partitioning and decoupling in the early Cenozoic. This resulted in intense deformation of Lower Devonian sedimentary rocks and in the formation of bedding-parallel décollements, e.g., between the Lower Devonian Wood Bay and the uppermost Pennsylvanian–lowermost Permian Wordiekammen formations. This suggests that intense deformation within Devonian rocks in Dickson Land can be explained by Eurekan deformation alone. Eurekan deformation also resulted in the formation of WNW–ESE- and N–S- to NNE–SSW-trending, kilometer-wide, open folds such as the Petuniabukta Syncline, and in inversion and/or overprinting of Early Devonian to Early Pennsylvanian normal faults by sinistral-reverse Eurekan thrusts. WNW–ESE-striking faults merge at depth with similarly trending and dipping ductile shear zone fabrics in Proterozoic basement rocks, which likely formed during the Timanian Orogeny. Conclusions A NNE-dipping shear zone, which is part of a large system of Timanian thrusts in the Barents Sea, controlled the formation of WNW–ESE-striking Devonian–Mississippian normal faults and syn-tectonic ... |
format |
Text |
author |
Koehl, Jean-Baptiste P. Allaart, Lis Noormets, Riko |
author_facet |
Koehl, Jean-Baptiste P. Allaart, Lis Noormets, Riko |
author_sort |
Koehl, Jean-Baptiste P. |
title |
Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard |
title_short |
Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard |
title_full |
Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard |
title_fullStr |
Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard |
title_full_unstemmed |
Devonian–Carboniferous extension and Eurekan inversion along an inherited WNW–ESE-striking fault system in Billefjorden, Svalbard |
title_sort |
devonian–carboniferous extension and eurekan inversion along an inherited wnw–ese-striking fault system in billefjorden, svalbard |
publisher |
F1000 Research Limited |
url |
https://doi.org/10.12688/openreseurope.15936.2 |
long_lat |
ENVELOPE(16.417,16.417,78.563,78.563) ENVELOPE(16.000,16.000,78.667,78.667) ENVELOPE(16.532,16.532,78.687,78.687) ENVELOPE(165.500,165.500,-74.217,-74.217) ENVELOPE(16.756,16.756,78.697,78.697) |
geographic |
Barents Sea Billefjorden Dickson Land Petuniabukta Svalbard Wood Bay Wordiekammen |
geographic_facet |
Barents Sea Billefjorden Dickson Land Petuniabukta Svalbard Wood Bay Wordiekammen |
genre |
Barents Sea Billefjorden Dickson Land Svalbard Spitsbergen |
genre_facet |
Barents Sea Billefjorden Dickson Land Svalbard Spitsbergen |
op_source |
Open Research Europe 2023 3:124 |
op_relation |
https://doi.org/10.12688/openreseurope.15936.1 https://doi.org/10.12688/openreseurope.15936.2 |
op_rights |
open access |
op_doi |
https://doi.org/10.12688/openreseurope.15936.210.12688/openreseurope.15936.1 |
_version_ |
1785579791654584320 |