Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved]
Background The Trollfjorden–Komagelva Fault Zone is the southernmost thrust fault of the Timanian Orogen and extends for thousands of kilometers from northwestern Russia to northern Norway. Though there is little about its location onshore northeastern Norway, where it is mapped as a major fault sys...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
F1000 Research Ltd
2024-10-01
|
| Series: | Open Research Europe |
| Subjects: | |
| Online Access: | https://open-research-europe.ec.europa.eu/articles/4-30/v2 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832592019977928704 |
|---|---|
| author | Eirik Stokmo Jean-Baptiste P. Koehl |
| author_facet | Eirik Stokmo Jean-Baptiste P. Koehl |
| author_sort | Eirik Stokmo |
| collection | DOAJ |
| description | Background The Trollfjorden–Komagelva Fault Zone is the southernmost thrust fault of the Timanian Orogen and extends for thousands of kilometers from northwestern Russia to northern Norway. Though there is little about its location onshore northeastern Norway, where it is mapped as a major fault system dominantly comprised of NNE-dipping thrust faults, its continuation to the west below Caledonian nappes and offshore post-Caledonian sedimentary basins remains a matter of debate. Methods The present study provides a more definitive answer about the continuation of Trollfjorden–Komagelva Fault Zone west of the Varanger Peninsula by using seismic reflection, bathymetric, topographic, and magnetic data onshore Finnmark and offshore on the Finnmark Platform. Results The present study demonstrates that the Sørøya–Ingøya shear zone represents a portion of the Trollfjorden–Komagelva Fault Zone that was folded into a NE–SW orientation and reactivated as a top-southeast thrust during the Caledonian Orogeny, while other portions of the Trollfjorden–Komagelva Fault Zone (e.g., on the Varanger Peninsula) were reactivated as strike-slip faults. The study also documents the presence of another major, NNE-dipping Timanian shear zone with a similar geometry to the Trollfjorden–Komagelva Fault Zone north of the Varanger Peninsula. Conclusions The Trollfjorden–Komagelva Fault Zone may continue offshore as a NE–SW-striking folded structure. This has the following implications: (1) the Seiland Igneous Province likely formed in a backarc setting, (2) metasedimentary rocks of the Kalak Nappe Complex deposited along the Baltican margin of the Iapetus Ocean, possibly in a late–post-Grenvillian collapse basin, (3) the Iapetus Ocean was much narrower than the several thousands of kilometers width commonly proposed, and (4) early Neoproterozoic magmatism in northern Norway is possibly related to the initial breakup of Rodinia. |
| format | Article |
| id | doaj-art-a8a20802ec4e432cb8066b72b61a7704 |
| institution | Kabale University |
| issn | 2732-5121 |
| language | English |
| publishDate | 2024-10-01 |
| publisher | F1000 Research Ltd |
| record_format | Article |
| series | Open Research Europe |
| spelling | doaj-art-a8a20802ec4e432cb8066b72b61a77042025-01-22T01:00:00ZengF1000 Research LtdOpen Research Europe2732-51212024-10-01420071Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved]Eirik Stokmo0Jean-Baptiste P. Koehl1https://orcid.org/0000-0001-7189-1988Brønnøy Kalk, Velfjord, Nordland, 8960, NorwayEarth and Planetary Sciences, McGill University, Montreal, Québec, H3A 0E8, CanadaBackground The Trollfjorden–Komagelva Fault Zone is the southernmost thrust fault of the Timanian Orogen and extends for thousands of kilometers from northwestern Russia to northern Norway. Though there is little about its location onshore northeastern Norway, where it is mapped as a major fault system dominantly comprised of NNE-dipping thrust faults, its continuation to the west below Caledonian nappes and offshore post-Caledonian sedimentary basins remains a matter of debate. Methods The present study provides a more definitive answer about the continuation of Trollfjorden–Komagelva Fault Zone west of the Varanger Peninsula by using seismic reflection, bathymetric, topographic, and magnetic data onshore Finnmark and offshore on the Finnmark Platform. Results The present study demonstrates that the Sørøya–Ingøya shear zone represents a portion of the Trollfjorden–Komagelva Fault Zone that was folded into a NE–SW orientation and reactivated as a top-southeast thrust during the Caledonian Orogeny, while other portions of the Trollfjorden–Komagelva Fault Zone (e.g., on the Varanger Peninsula) were reactivated as strike-slip faults. The study also documents the presence of another major, NNE-dipping Timanian shear zone with a similar geometry to the Trollfjorden–Komagelva Fault Zone north of the Varanger Peninsula. Conclusions The Trollfjorden–Komagelva Fault Zone may continue offshore as a NE–SW-striking folded structure. This has the following implications: (1) the Seiland Igneous Province likely formed in a backarc setting, (2) metasedimentary rocks of the Kalak Nappe Complex deposited along the Baltican margin of the Iapetus Ocean, possibly in a late–post-Grenvillian collapse basin, (3) the Iapetus Ocean was much narrower than the several thousands of kilometers width commonly proposed, and (4) early Neoproterozoic magmatism in northern Norway is possibly related to the initial breakup of Rodinia.https://open-research-europe.ec.europa.eu/articles/4-30/v2Baltica Neoproterozoic Paleozoic Timanides Timanian Orogeny Caledonideseng |
| spellingShingle | Eirik Stokmo Jean-Baptiste P. Koehl Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved] Open Research Europe Baltica Neoproterozoic Paleozoic Timanides Timanian Orogeny Caledonides eng |
| title | Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved] |
| title_full | Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved] |
| title_fullStr | Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved] |
| title_full_unstemmed | Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved] |
| title_short | Caledonian reactivation and reworking of Timanian thrust systems and implications for latest Mesoproterozoic to mid-Paleozoic tectonics and magmatism in northern Baltica [version 2; peer review: 1 approved, 2 approved with reservations, 1 not approved] |
| title_sort | caledonian reactivation and reworking of timanian thrust systems and implications for latest mesoproterozoic to mid paleozoic tectonics and magmatism in northern baltica version 2 peer review 1 approved 2 approved with reservations 1 not approved |
| topic | Baltica Neoproterozoic Paleozoic Timanides Timanian Orogeny Caledonides eng |
| url | https://open-research-europe.ec.europa.eu/articles/4-30/v2 |
| work_keys_str_mv | AT eirikstokmo caledonianreactivationandreworkingoftimanianthrustsystemsandimplicationsforlatestmesoproterozoictomidpaleozoictectonicsandmagmatisminnorthernbalticaversion2peerreview1approved2approvedwithreservations1notapproved AT jeanbaptistepkoehl caledonianreactivationandreworkingoftimanianthrustsystemsandimplicationsforlatestmesoproterozoictomidpaleozoictectonicsandmagmatisminnorthernbalticaversion2peerreview1approved2approvedwithreservations1notapproved |