The final of four episodes of "The Wilson Cycle" series. This is Episode 4: Mountain-building by continent-continent collision.
In this episode, we visit several localities with spectacular eclogites in Western Norway. These provide the evidence for the former deep burial and formation of a very thick, Himalayan type continental crust during the Caledonian continental collision between Baltica and Laurentia. The association of exposed mantle-rocks and the eclogite facies minerals formed at high- and ultra-high pressure conditions at 405 to 395 million years ago during the burial under the Caledonian Mountains in Scandinavia, provide solid evidence for the former presence of very thick orogenic lithosphere and consequently the former presence of very high, Himalayan-type mountains in Scandinavia. In the final stage of the Caledonian Wilson Cycle we find geological evidence for orogenic collapse, eduction, and formation of large-scale extensional detachments and discuss how this complicated set of observations can explain how these rocks, once deeply buried under the vast Caledonian mountains, now can be studied at the Earth's surface. The final part of our Caledonian Wilson Cycle story ends with a visit to a spectacular outcrop of a major Post-Caledonian Normal Fault, the Lærdal-Gjende Fault, where we discuss the end of the Caledonian Wilson Cycle and discuss the initiation of a new, as witnessed by the renewed continental break-up and oceanic opening associated with the present-day North Atlantic Ocean and the Norwegian-Greenland Sea.
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Join us to discover the Wilson Cycle, one of the most fundamental concepts in geology. The “Wilson Cycle” explains the process of orogeny, which related to the formation of the world's large-scale mountain belts by a series geological events. The various elements of Wilson Cycle (and the Supercontinent Cycle, more broadly) have underpinned and inspired many of the research undertaken over the last 10 years at CEED.
Production, financial support and acknowledgements:
The Centre for Earth Evolution and Dynamics (CEED) at the University of Oslo (UiO), Norway.
License: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Professor Torgeir B. Andersen (CEED, UiO) and his former PhD students/Post Doc at CEED, Dr Hans-Jørgen Kjøll (now at IG-UiO) and Dr Johannes Jakob (now at NGU) guide us through the geotraverse and explained details of the geological observations.
Dr Valentina Magni (CEED, UiO) shows and explains some computer simulations to illustrate elements of Wilson Cycle Tectonics, such as subduction and Island-arc formation and eduction.
Dr Dougal Jerram (CEED, UiO) is the narrator, asks all the important questions and introduces and summarise explanations underway.
Assistant Professor Owen Anfinson (Sonoma State University, U.S.A) helped with skilful drone-piloting under the instruction of main photographer Andrew Blix, who together with Dougal Jerram have edited and produced the final four clips of our Wilson Cycle movie.
Norwegian Research Council's financial support to CEED and the Fri-Nat Project “Hyper-extension along the Pre-Caledonian margin of Baltica” together with the INTPART NOR-R-AM and NOR-R-AM2 "Changes at the Top of the World through Volcanism and Plate Tectonics: Arctic Norwegian-Russian-North American collaboration" project financed the film project.
SGC (Sunnfjord Geo-Centre) with Einar Alsaker is thanked for help and guidance during visit to the Staveneset copper mine. Knutholmen A/S w/Svein Fosse provided the boats used during filming.
We hope you have enjoyed the series!
