MagNetZ With Boris Robert (2022/06/29) - High velocity polar wander in West Africa
Channel: MagNetZ
Date: 2022-06-29

High velocity polar wander in West Africa: implications on the Ediacaran magnetic field

The video is also available for download at: https://earthref.org/ERDA/2534/
and can be referenced with the doi: 10.7288/V4/ERDA/2534

Title: High velocity polar wander in West Africa: implications on the Ediacaran magnetic field
Author: Boris Robert from GFZ Potsdam, Germany

The Ediacaran (635-541 Ma) is a geological period of extreme changes in the superficial layers of the Earth (biosphere, cryosphere, oceans, atmosphere). The paleomagnetic data from the main continents of this epoch display very fast polar wander excursions, which seem to occur simultaneously on several continents. Two main competing hypotheses have been proposed in the literature to explain these data: (1) very fast True Polar Wander episodes (TPW), which represent the global movement of the mantle and the crust relative to the spin axis, or (2) perturbations of the Earth’s magnetic field. On geological timescales, the TPW is speed-limited to some degrees per million year while magnetic field changes could be much faster (degrees per kyr). The velocity of the polar wander excursions of the Ediacaran is therefore a critical parameter to distinguish these two families of solutions. In this presentation, I will present new high precision CA ID TIMS data from the Ouarzazate Group in Morocco and discuss the two hypotheses based on these new geochronological constraints. 


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00:00 - Intro
00:58 - Presentation
28:18 - Questions
39:25 - Announcements