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Timing the break-up...
Timing the break-up of the Baltica and Laurentia connection in Nuna – Rapid plate motion oscillation and plate tectonics in the Mesoproterozoic
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- Salminen, J. (author)
- Geological Survey of Finland, P.O. Box 96, FI-02151 Espoo, Finland; Department of Geosciences and Geography, P.O. Box 64, FI-00014 University of Helsinki, Finland
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- Elming, Sten-Åke (author)
- Luleå tekniska universitet,Geovetenskap och miljöteknik
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- Layer, P. (author)
- Geophysical Institute and Department of Geosciences, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
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Geological Survey of Finland, PO. Box 96, FI-02151 Espoo, Finland; Department of Geosciences and Geography, P.O. Box 64, FI-00014 University of Helsinki, Finland Geovetenskap och miljöteknik (creator_code:org_t)
- Elsevier B.V. 2023
- 2023
- English.
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In: Precambrian Research. - : Elsevier B.V.. - 0301-9268 .- 1872-7433. ; 384
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Abstract
Subject headings
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- Meso– to Neoproterozoic geological and paleomagnetic data support a direct connection between Baltica and Laurentia in both Nuna and Rodinia supercontinents, however in different relative configurations. Previous paleomagnetic data limit the time of break-up of Nuna core configuration and ca. 90° rotation of Baltica relative to Laurentia between 1.27 Ga and 0.99 Ga. Despite the well documented relative motion of continents, the tectonic mode during the Meso– to Neoproterozoic has been questioned and the operation of single lid tectonics at 1.6–1.0 Ga during the Nuna-Rodinia supercontinent cycles has been proposed.In this study, new paleomagnetic and whole rock 40Ar-39Ar geochronological data from a basic dyke in Stugun central Sweden are combined with coeval data to produce a 1.22 Ga (1.244–1.200 Ga) moderate-quality paleomagnetic pole. This is done to better estimate the break-up time of the core of Nuna and explore the plate tectonics at the Mesoproterozoic. The new pole fills part of the 1.247–1.140 Ga gap in the paleomagnetic record of Baltica. By comparing apparent polar wander paths (APWPs) and calculated drift velocities, a break-up of Baltica and Laurentia at 1.12–1.04 Ga is suggested. Plate velocities calculated for Laurentia, Baltica and Siberia for the time of the Nuna supercycle are similar and low to moderately high corresponding with the present-day tectonic speeds. Furthermore, the obtained velocity peaks may be related with onset of the break-up of the Nuna supercontinent, the break-up of the direct Baltica–Laurentia connection in Nuna and nascent Rodinia. We suggest that the velocity peaks and large oscillating shifts in late Mesoproterozoic pole positions for Laurentia and Baltica result from a combination of relative plate motion and inertial interchange true polar wander (IITPW) events. Both IITPW events and relative plate motions argue for an operation of plate tectonics in the Meso– to Neoproterozoic.
Subject headings
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geology (hsv//eng)
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Geofysik (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geophysics (hsv//eng)
Keyword
- 40Ar-39Ar geochronology
- Baltica
- Drift velocities
- Inertial interchange true polar wander
- NENA
- Nuna
- Paleomagnetism
- Tillämpad geofysik
- Applied Geophysics
Publication and Content Type
- ref (subject category)
- art (subject category)
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