Rapid Early Cambrian rotation of Gondwana

Abstract

Research Article| August 01, 2010 Rapid Early Cambrian rotation of Gondwana Ross N. Mitchell; Ross N. Mitchell Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, Connecticut 06511, USA Search for other works by this author on: GSW Google Scholar David A.D. Evans; David A.D. Evans Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, Connecticut 06511, USA Search for other works by this author on: GSW Google Scholar Taylor M. Kilian Taylor M. Kilian Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, Connecticut 06511, USA Search for other works by this author on: GSW Google Scholar Geology (2010) 38 (8): 755–758. https://doi.org/10.1130/G30910.1 Article history received: 28 Nov 2009 rev-recd: 21 Mar 2010 accepted: 25 Mar 2010 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Ross N. Mitchell, David A.D. Evans, Taylor M. Kilian; Rapid Early Cambrian rotation of Gondwana. Geology 2010;; 38 (8): 755–758. doi: https://doi.org/10.1130/G30910.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Based on the history of Mesozoic–Cenozoic plate motions, as well as simple dynamical considerations, a “speed limit” for tectonic plates has been suggested at ∼20 cm/yr. Previous paleomagnetic data from the Early Cambrian of Gondwana are conflicting but generally imply rapid motions approaching that limit. Herein we describe results from a continuous paleomagnetic sampling of Lower to Middle Cambrian strata from the Amadeus Basin, central Australia. We find characteristic remanence directions that show an ∼60° declination shift through the section. Assuming a tectonically assembled Gondwana supercontinent by Early Cambrian time, this large vertical-axis rotation of its Australian sector corresponds to an equally large translation across paleolatitudes for its Brazilian and West African sectors. Analysis of all high-quality paleomagnetic data from Gondwana both confirms and constrains the 60° rotation to have occurred toward the end of Early Cambrian time, at rates exceeding 16 +12/–8 cm/yr. These observations suggest that either nonuniformitarian plate tectonics or an episode of rapid true polar wander occurred during the Cambrian “explosion” of animal life. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.