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Published September 2006 | public
Journal Article

Combined paleomagnetic, isotopic, and stratigraphic evidence for true polar wander from the Neoproterozoic Akademikerbreen Group, Svalbard, Norway

Abstract

We present new paleomagnetic data from three Middle Neoproterozoic carbonate units of East Svalbard, Norway. The paleomagnetic record is gleaned from 50 to 650 m of continuous, platformal carbonate sediment, is reproduced at three locations distributed over >100 km on a single craton, and scores a 5–6 (out of 7) on the Van der Voo (1990) reliability scale. Two >50° shifts in paleomagnetic direction are coincident with equally abrupt shifts in δ^(13)C and transient changes in relative sea level. We explore four possible explanations for these coincidental changes: rapid plate tectonic rotation during depositional hiatus, magnetic excursions, nongeocentric axial-dipole fields, and true polar wander. We conclude that the observations are explained most readily by rapid shifts in paleogeography associated with a pair of true polar wander events. Future work in sediments of equivalent age from other basins can test directly the true polar wander hypothesis because this type of event would affect every continent in a predictable manner, depending on the continent's changing position relative to Earth's spin axis.

Additional Information

© 2006 Geological Society of America. Manuscript Received 28 August 2005. Revised Manuscript Received 27 April 2006. Manuscript Accepted 30 April 2006. This work was supported by the National Science Foundation (Arctic Natural Sciences Research Program grant OPP-9817244), the National Aeronautics and Space Administration (NASA) Astrobiology Institute, the Canadian Institute for Advanced Research (Earth System Evolution Project), the Tectonics Special Research Centre (Perth, Australia), and the Agouron Institute. Critical reviews from John Geissman, Arlo Weil, Joseph Meert, David Bice, and Rob Van der Voo improved the manuscript. Additionally, the paper benefited from useful discussions with David Barbeau, Thorsten Becker, Michael Bender, Jeremy Bloxham, Sam Bowring, Bruce Buffett, Mathieu Dumberry, David Evans, David Fike, John Grotzinger, Ebbe Hartz, John Hayes, Matthew Hurtgen, David Jones, Jamie Kellogg, Andy Knoll, Francis Macdonald, Jerry Mitrovica, Jon Mound, Richard O'Connell, Ryan Petterson, Susannah Porter, Pascale Poussart, Timothy Raub, David Rowley, Jorge Sarmiento, John Suppe, Ben Sheets, Sabine Stanley, Nick Swanson-Hysell, Carl Tape, and Trond Torsvik. Jean-Pascal Cogné provided tireless support with his excellent paleomagnetics software. Norsk Polarinstitutt, Airlift, and the crew of the vessel Farm made Svalbard logistics more manageable. Cris Carman, Anne Estoppey, John Higgins, Matt Hurtgen, Leslie Hsu, Brice Jones, Peter Moore, and Meg Smith provided assistance in the field. Ethan Goddard and Greg Eischeid supervised the isotope laboratory work at Harvard University. Bob Kopp helped keep the paleomagnetics laboratory at Caltech running smoothly, while Roberta Bennett-Calorio made working at MIT a pleasure. Caroline Ross, Fernando Castaño, Debbie Morecroft, and Vikram Sivakumar facilitated vibrating sample magnetometer experiments and Fang Cheng Chou trained us on the Magnetic Property Measurement System (MPMS). Nilanjan Chatterjee and Tim Grove helped us with electron microprobe measurements.

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023