Precisely locating the Ordovician equator in Laurentia

Abstract

Research Article| February 01, 2013 Precisely locating the Ordovician equator in Laurentia Jisuo Jin; Jisuo Jin 1Department of Earth Sciences, Western University, London, Ontario N6A 5B7, Canada Search for other works by this author on: GSW Google Scholar David A.T. Harper; David A.T. Harper 2Department of Earth Sciences, Durham University, Durham DH1 3LH, UK Search for other works by this author on: GSW Google Scholar L. Robin M. Cocks; L. Robin M. Cocks 3Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK Search for other works by this author on: GSW Google Scholar Phil J.A. McCausland; Phil J.A. McCausland 1Department of Earth Sciences, Western University, London, Ontario N6A 5B7, Canada Search for other works by this author on: GSW Google Scholar Christian M.Ø. Rasmussen; Christian M.Ø. Rasmussen 4Natural History Museum of Denmark, University of Copenhagen, 1350 Copenhagen K, Denmark Search for other works by this author on: GSW Google Scholar Peter M. Sheehan Peter M. Sheehan 5Department of Geology, Milwaukee Public Museum, Milwaukee, Wisconsin 53233, USA Search for other works by this author on: GSW Google Scholar Geology (2013) 41 (2): 107–110. https://doi.org/10.1130/G33688.1 Article history received: 29 May 2012 rev-recd: 05 Jul 2012 accepted: 06 Jul 2012 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 Jisuo Jin, David A.T. Harper, L. Robin M. Cocks, Phil J.A. McCausland, Christian M.Ø. Rasmussen, Peter M. Sheehan; Precisely locating the Ordovician equator in Laurentia. Geology 2013;; 41 (2): 107–110. doi: https://doi.org/10.1130/G33688.1 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 The Late Ordovician equatorial zone, like the zone today, had few hurricane-grade storms within 10° of the equator, as emphasized by the preservation of massive-bedded Thalassinoides ichnofacies in a trans-Laurentian belt more than 6000 km long, from the southwestern United States to North Greenland. That belt also includes nonamalgamated shell beds dominated by the brachiopod Proconchidium, which would not have been preserved after hurricane-grade storms. The belt lacks such storm-related sedimentary features as rip-up clasts, hummocky cross-stratification, or large channels. In contrast, other contemporaneous Laurentian Thalassinoides facies and shell beds on either side of the belt have been disturbed by severe storms below fair-weather wave base. The position of the biofacies-defined equatorial belt coincides with the Late Ordovician equator deduced from paleomagnetic data from Laurentia, thus providing both a high-precision equatorial location and an independent test of the geocentric axial dipole hypothesis for that time. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.