Presentation of the "Orogenic Bridge Theory" at UiT The Arctic University of Norway in Tromsø, Norway

Jean-Baptiste Koehl presented the Orogenic Bridge Theory at UiT The Arctic University of Norway in Tromsø. The presentation led to extensive discussion of the potential implications the Orogenic Bridge Theory may have on the Geosciences in the upcoming years. The Orogenic Bridge Theory basically states that orogens striking parallel to propagating oceanic rifts will facilitate the opening of the rift and control the geometry and strike of associated extensional structures (e.g., localization of metamorphic core complexes and hyperextended margins, and determination of hyperextended margin asymmetry), whereas orogens highly oblique to orthogonal to opening rifts will prevent propagation, force the rift to reorient and step laterally, and localize the formation of major transform faults and transform-parallel oceanic core complexes. Thus far, potential implications of the theory include the occurrence of lawsonite-blueschist metamorphism also during continent-continent collision, the presence of old (i.e., older than seafloor spreading) continental mantle at transform-parallel oceanic core complexes, the location and orientation of future rifts  (along inherited orogens at the edge of Large Low-Shear Velocity Provinces at the Core-Mantle Boundary), where opening rifts will step and merge with other opening rifts, the location of future (metamorphic and oceanic) core complexes, and the troubleshooting of existing plate tectonics models and of major fault zones inferred indirectly (e.g., Wegener Fault and De Geer Zone both invalidated by the theory).

The presentation can be found on Jean-Baptiste's ResearchGate:

Koehl, J.-B. P.: The Orogenic Bridge Theory: a predictive tool for past and future plate tectonics, Friday Seminar, UiT The Arctic University of Norway in Tromsø, Tromsø, Norway, 09.06.2023. http://dx.doi.org/10.13140/RG.2.2.24799.84643

https://www.researchgate.net/publication/371492242_The_Orogenic_Bridge_Theory_a_predictive_tool_for_past_and_future_plate_tectonics

The attached slide from the presentation shows occurrence of potentially three bridges of orogenic crust (i.e., tectonically thickened continental crust) in the Davis Strait (Nagssugtuqidian Orogen; purpe lines), the Greenland-Iceland-Faroe Ridge (Caledonian Orogen or Sorgenfrei-Teysseire-Tornquist Zone; orange lines), and in the Fram Strait (Timanian Orogen; red lines).

New TED-Ed Lesson released

TED-Ed just released a new educational video about plate tectonics reconstructions of which Jean-Baptiste Koehl is the lead author. The video details how the continents are accreted into supercontinents and then rifted apart according to the early Continental Drift Theory of Alfred Wegener. The video also shows the impact of plate tectonics on climate and potential solutions to mitigate these, and offers a glimpse of the potential future supercontinent.

The presentation can be found on YouTube and on TED-Ed's webpage:

Koehl, J.-B. P., Araujo, I, Anderson, A., Bhayani, S., Lan, Z., Smalley, L., Xhelo, G., Bechtol, A., Rosenthal, A., Kwartler, D. and Gillespie, I.: “The continents are moving. When will they collide?”, TED-Ed, release date: 02.03.2023; number of views: > 251 000.

https://www.youtube.com/watch?v=SbIpWHQI-tE

https://ed.ted.com/lessons/the-continents-are-moving-when-will-they-collide-jean-baptiste-p-koehl

The attached screenshot from the video shows the tremendous impact of plate tectonics on Earth's climate. When the Rodinia Supercontinent broke up some 750 million years ago, more continental crust became exposed to weathering and absorbed more CO2 from rainfall. As a result, the Earth was almost or completely covered in ice in a period called Snowball Earth.

Presentation at the University of Portsmouth

Jean-Baptiste Koehl presented the results of a study of the Indio Hills portion of the San Andreas fault published in Solid Earth in summer 2022. The work has implications for the movement history and the role of various types of structures along major strike-slip faults, and for the location of the next large earthquake along the San Andreas fault. The presentation received the interest and questions of 40 researchers and students.

The presentation can be found on Jean-Baptiste's ResearchGate:

Koehl, J.-B. P., Bergh, S. G. and Sylvester, A. G.: From transtension to transpression and implications for the next Big One along the San Andreas fault, University of Portsmouth, Portsmouth, UK, Weekly Seminar, 16.02.2023. http://dx.doi.org/10.13140/RG.2.2.34234.26561

https://www.researchgate.net/publication/369095236_From_transtension_to_transpression_and_implications_for_the_next_Big_One_along_the_San_Andreas_fault

The attached slide from the presentation shows the gradual converging of earthquakes along the Landers Mojave Line segment of the East California shear zone towards the Indio Hills segment of the San Andreas fault, where the San Andreas fault and the Indio Hills fault form a dextral freeway junction.

Meeting with the Geological Survey of Norway

Jean-Baptiste Koehl presented the results of K–Ar analyses of fault rocks on Bjørnøya in partnership with Göttingen University and UiT The Arctic University of Norway in Tromsø to the Geological Survey of Norway. During the meeting, the participants discussed a potential collaboration for a joint publication.

The presentation can be found on Jean-Baptiste's ResearchGate:

Koehl, J.-B. P.: K–Ar analyses of fault rocks on Bjørnøya and implications for the Neoproterozoic–Cretaceous tectonic history of the Barents Sea, Geological Survey of Norway, online presentation, 16.12.2022.

https://www.researchgate.net/publication/366353145_K-Ar_analyses_of_fault_rocks_on_Bjornoya_and_implications_for_the_Neoproterozoic-Cretaceous_history_of_the_Barents_Sea

The attached slide is from the presentation and shows the Late Cretaceous age and reverse kinematic indicators obtained for presumed Late Devonian–Carboniferous normal faults onshore Bjørnøya. The detrital illite content also confirms a late Famennian age for the Billefjorden Group on Bjørnøya.

EQP Meeting, McGill University, Montreal, Canada

Jean-Baptiste Koehl presented the ArcTec project and early results to the Earthquake Processes Group at the Department of Earth and Planetary Sciences at McGill University.

The presentation can be found on Jean-Baptiste's ResearchGate:

Koehl, J.-B. P.: A 600 million year odyssey linked to recent earthquakes in Svalbard, Norwegian Arctic, EQP meeting, McGill University, online presentation, 25.11.2022.

https://www.researchgate.net/publication/365853584_A_600_million_year_odyssey_linked_to_recent_earthquakes_in_Svalbard_Norwegian_Arctic

The attached slide is from the presentation and shows the evolution of the Storfjorden Seismic Sequence with spreading of tectonic movement and earthquakes from a deep fault surface in 2008 (main quake) to a shallower one in 2010.

Fieldwork to Kongsfjorden, Svalbard (TOWS project)

Jean-Baptiste Koehl and Eirik Stokmo carried out fieldwork related to the TOWS (The Timanian Orogeny in western Spitsbergen; funded by an Arctic Field Grant of the Svalbard Science Forum) and ArcTec projects in Kongsfjorden in early September 2022, in collaboration with KingsBay A.S. and the Norwegian Polar Institute in Ny-Ålesund. The fieldwork targeted the potential continuation of a major NNE-dipping Timanian thrust in Kongsfjorden, the Kongsfjorden–Cowanodden fault zone (see also related publication doi.org/10.5194/se-13-85-2022).

Two datasets related to the fieldwork are available open access from DataverseNO:

-Koehl, J.-B. P. and Bache Stokmo, E. M.: Structural field measurements in Proterozoic basement, Devonian, and Carboniferous rocks in Kongsfjorden, September 2022, 2022. https://doi.org/10.18710/APGAWL

-Koehl, J.-B. P. and Bache Stokmo, E. M.: Fieldwork photographs Kongsfjorden September 2022, 2022. https://doi.org/10.18710/KEB2MM

Photo: Løvlandfjellet in Haakon VII Land showing marbles of the Generalfjella Formation (Neoproterozoic; left hand-side) over red-colored Devonian sedimentary rocks (right hand-side).

International Conference on Arctic Margins 9, Ottawa, Canada

Jean-Baptiste Koehl presented the results of (1) a new manuscript submitted to Tektonika (new Diamond Open Access Journal; tektonika.online/index.php/home/index) about a Timanian fold-and-thrust belt in the Loppa High, and (2) ongoing work about Timanian thrust systems and the De Geer Zone in Svalbard at the International Conference on Arctic Margins 9 in Ottawa, Canada. He also convened session 11 "Neoproterozoic Circum-Arctic Tectonic Events and Correlations".

The two abstracts can be found on Jean-Baptiste's ResearchGate:

(1) Koehl, J.-B. P., Polonio, I. and Rojo, L.: Timanian fold and thrust system and Caledonian overprint in the Loppa High, Norwegian Barents Sea, International Conference on Arctic Margins 9, 12–16th June, Ottawa, Canada, 2022.

https://www.researchgate.net/publication/362467676_Timanian_fold-and-thrust_system_and_Caledonian_overprint_in_the_Loppa_High_Norwegian_Barents_Sea

(2) Koehl, J.-B. P.: The myth of the De Geer Zone, International Conference on Arctic Margins 9, 12–16th June, Ottawa, Canada, 2022.

www.researchgate.net/publication/362467693_The_myth_of_the_De_Geer_Zone)

The attached slide is from Koehl (2022).

Friday Seminar, UiT The Arctic University of Norway in Tromsø

Jean-Baptiste Koehl presented the results of an upcoming manuscript (to be submitted to Tektonika, a new Diamond Open Access Journal; tektonika.online/index.php/home/index) about a Timanian thrust system in the Loppa High (Norwegian Barents Sea) and its reworking during the Caledonian Orogeny at the weekly Friday Seminar at the Department of Geosciences at UiT The Arctic University of Norway in Tromsø.

The abstract and presentation are available from Jean-Baptiste's ResearchGate:

Koehl, J.-B. P., Polonio, I. and Rojo, L.: The nature of basement rocks in the Loppa High revealed by new seismic attributes and spectral decomposition, Friday Seminar, Department of Geosciences, UiT The Arctic University of Norway in Tromsø, Tromsø, Norway, 13.05.2022.

https://www.researchgate.net/publication/360851411_The_nature_of_basement_rocks_in_the_Loppa_High_revealed_by_new_3D_seismic_attribute_and_spectral_decomposition?_sg%5B0%5D=2udRewauZeh9-Ju4w_1Zkm9nfQnTWCIzDGEiWYqI1hlLJJ8kswsOASn_tJW-ZmgujtuWXw6XFz6zq6hnDeOyzKK9ADFlMHhRF0EjQDBj.ifGSJDFQMpTO6pCb0JgyALvcpu4bx94pSQNz97dMuHT6n4Yea7G2m9yWWzfxYH425jZLgeoGjSWeWJeX4f8YJA

Attached slide from the presentation showing the main Timanian thrust system in the Selis Ridge (western Loppa High).

CAGE Seminar, UiT The Arctic University of Norway in Tromsø

Jean-Baptiste Koehl was invited to present the results of two recently published, peer-reviewed manuscript about (1) the Billefjorden Fault Zone north of Svalbard, and (2) Timanian thrust systems in the northern Norwegian Barents Sea and Svalbard at the weekly seminar of the Centre for Arctic Gas Hydrate, Climate and Environment at UiT The Arctic University of Norway in Tromsø.

The presentation is available from Jean-Baptiste's ResearchGate:

Koehl, J.-B. P.: The Billefjorden Fault Zone and Timanian thrust systems in the Barents Sea and Svalbard, Centre for Arctic Gas Hydrate, Environment and Climate (CAGE) Seminar, online presentation, 10.03.2022. 

https://www.researchgate.net/publication/359143675_The_Billefjorden_Fault_Zone_and_Timanian_thrust_systems_in_Svalbard_and_the_Barents_Sea

The two peer-reviewed articles are available free of charge on the journal's page:

(1) Koehl, J.-B. P. and Allaart, L.: The Billefjorden Fault Zone in northern Spitsbergen: A major terrane boundary?, Polar Research, 40, 7668, 9 pp., 2021.

(2) Koehl, J.-B. P., Magee, C. and Anell, I. M.: Timanian thrust systems and their implications for the late Neoproterozoic–Phanerozoic tectonic history of the northern Barents Sea and Svalbard, Solid Earth, 13, 85–115, 2022.

Attached slide from the presentation showing the Pyramiden Mountain in central Spitsbergen, a key locality to define the Billefjorden Fault Zone (from left to right: greyish and purple Devonian sedimentary rocks of the Wood Bay Formation, coal-rich, black and yellowish sedimentary rocks of the Billefjorden Group, and reddish and yellowish sedimentary rocks of the Gipsdalen Group).

CAGE Seminar, UiT The Arctic University of Norway in Tromsø

Pint of Science Norway, an organization focusing on getting scientists to present their work at local pubs in an entertaining way, invited Jean-Baptiste to give a presentation (live on youtube) of the results of ArcTec at Brygg in Oslo. Jean-Baptiste helped founding Pint of Science in 2020.

The presentation is available from Jean-Baptiste's ResearchGate:

Koehl, J.-B. P.: Sleeping giants, Waiting for #pint22: latest news from France, Pint of Science Norway, Oslo, hybrid event (live on YouTube: www.youtube.com/watch?v=Bv_AgCFGcq4, 21’30’’–37’30’’), 06.12.2021. 

https://www.researchgate.net/publication/359280163_Sleeping_giants?_sg%5B0%5D=VKMMg0HAPAdDfoKwKGUrHgxb5xza8t6hXa_87tTVfTGJWXAfcNjlrCVOMLGYVXCemIwn1pZuPyt62YbOhPZWubHMKMAcoOUaWjmd6Klm._eXvq4G1mNNqzHqRF-tvafLew062hRtUN0ACEcX7QxB7thjXFzLcYT3iURIO53YVfVNy_vDShUmY1Fi_ZBbUyA

The recording of the presentation is available on youtube:

www.youtube.com/watch?v=Bv_AgCFGcq4 (minute 21’30’’–37’30’’)

Attached slide from the presentation showing two realistic movies about geohazards (Skjelvet – The Earthquake, Bølgen – The Wave).

Seminar at the Polish Academy of Science

Jean-Baptiste Koehl was invited to present the results of ongoing work related to the ArcTec project in Svalbard and the Barents Sea at the weekly seminar of the Polish Academy of Science in Warsaw, Poland.

The presentation is available from Jean-Baptiste's ResearchGate:

Koehl, J.-B. P.: Seismic study of major faults in Svalbard and the Barents Sea, Polish Academy of Science Seminar, online presentation, 03.12.2021.

https://www.researchgate.net/publication/356756758_Seismic_study_of_major_faults_in_Svalbard_and_the_Barents_Sea?_sg%5B0%5D=Y0E61M9zQTjv8EdcMc2DJJJFgon1EW7zzlUNUZwU2bj0Jg84PGrZmh2oRLW6lSOdRMZ_0wngV4G_aJnYcOdasMSZI0StBJhaZO9Bef7z.o4ZRj1Lw1WOYVOA-ijkDZC3pCsAN1oDElkunNHyyPIM1Hz0tIVNxf40eSDORpD4VgeXbDRdtqBvMfszxXDWUlA

Attached slide from the presentation showing the seismic expression of the NNE-dipping Kongsfjorden–Cowanodden fault zone in Storfjorden (just east of Spitsbergen).

The ArcTec project presented as a keynote lecture at the EGU

Jean-Baptiste Koehl was invited to present the ArcTec project as a keynote lecture at the Arctic Connection session of the Geodynamics group at the EGU General Assembly 2020. 

The abstract and presentation are available from Jean-Baptiste's ResearchGate:

Koehl, J.-B. P.: Impact of Timanian thrusts on the Phanerozoic tectonic history of Svalbard, EGU General Assembly, Keynote presentation, Vienna, Austria, 04.05.2020. 

https://www.researchgate.net/publication/341940339_Impact_of_Timanian_thrusts_on_the_Phanerozoic_tectonic_history_of_Svalbard?_sg%5B0%5D=P6VK0XvSKX3d7_EvvN4cpUpNG3GBFUjfE_NXUWG-JKM-uAQiQMNrLJNEzvtFuYlv9j5HXlrFW9-14emtg4DXFdRU4K0bWpnRYbOb9Ctm.n90smuhHIIycV8v1UQ-SXRdBWW4zhiWxMGCGW7o2fAhJVH-nVrIIiL7nO4ZNknyrr133-QvBuChI8EOrCgB1lg

Attached slide from the presentation showing a tectonic reconstructions for Baltica and Laurentia in the late Neoproterozoic to Phanerozoic. Major tectonic events include top-SSW contraction during the Timanian Orogeny coeval with the opening of the Iapetus Ocean (650–550 Ma), Caledonian contraction and folding of and reactivation of Timanian thrusts as sinistral-reverse faults (490–420 Ma), Eurekan contraction during the opening of Baffin Bay and the Labrador Sea with sinistral-reverse reactivation of Timanian thrusts (66–56 Ma), and rifting of the Fram Straight with development of major transform faults (Molloy and Spitsbergen fracture zones) along inherited Timanian thrusts and reactivation of Timanian thrusts as strike-slip faults (24–0 Ma).

The ArcTec project's hypotheses are presented for the first time

Jean-Baptiste Koehl presented the ArcTec project's hypotheses during a visit at UiT The Arctic University of Norway in Tromsø. The presentation gathered strong enthusiasm from the early-career scientists and passion from the more experienced researchers present.

The abstract and presentation are available from Jean-Baptiste's ResearchGate:

Impact of Timanian thrusts on the Phanerozoic tectonic history of Svalbard, Friday Seminar, Department of Geosciences, UiT The Arctic University of Norway in Tromsø, Tromsø, Norway, 13.09.2019. 

https://www.researchgate.net/publication/335833913_Impact_of_Timanian_thrusts_on_the_Phanerozoic_tectonic_history_of_Svalbard?_sg%5B0%5D=65lH1F8x2QTAWIYADjnH-GO1Y2RsEG3kz6HHJiqFOJJvYYqbg4OOaxUxZHCdhFZiD8btIAAu25w4aSZf_Wijz1vI_wwYjuHWWOUMvrfQ.dqOgJ0tRF02tg9qJ7bbYeszEqoHI2H5DWKhzNli0nnNkGOv0l51OfRTUta-qs6PIOQhfZcMyVrXbytLzVxdrtw

Attached slide from the presentation showing a potential correlation of Timanian thrusts (dashed purple lines) and related structures (e.g., transform faults; plain purple lines) across the Fram Straight with a major offset of the mid-ocean ridge (black lines). The black arrows show the initial stage of top-SSW Timanian contraction (650–550 Ma) and the black half arrows the subsequent partial reactivation of Timanian thrust systems as sinistral strike-slip faults (during the Caledonian Orogeny, Eurekan tectonic event, and late Cenozoic rifting).