Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands

Research Article| February 06, 2019 Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands Keith Dewing; Keith Dewing † 1Geological Survey of Canada, 3303-33rd St NW, Calgary, Alberta, Canada T2L 2A7 †keith.dewing@canada.ca Search for other works by this author on: GSW Google Scholar Thomas Hadlari; Thomas Hadlari 1Geological Survey of Canada, 3303-33rd St NW, Calgary, Alberta, Canada T2L 2A7 Search for other works by this author on: GSW Google Scholar D. Graham Pearson; D. Graham Pearson 2Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 Search for other works by this author on: GSW Google Scholar William Matthews William Matthews 3Department of Geoscience, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, Canada T2N 1N4 Search for other works by this author on: GSW Google Scholar Author and Article Information Keith Dewing † 1Geological Survey of Canada, 3303-33rd St NW, Calgary, Alberta, Canada T2L 2A7 Thomas Hadlari 1Geological Survey of Canada, 3303-33rd St NW, Calgary, Alberta, Canada T2L 2A7 D. Graham Pearson 2Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E3 William Matthews 3Department of Geoscience, University of Calgary, 2500 University Dr. NW, Calgary, Alberta, Canada T2N 1N4 †keith.dewing@canada.ca Publisher: Geological Society of America Received: 24 Apr 2018 Revision Received: 01 Oct 2018 Accepted: 01 Nov 2018 First Online: 06 Feb 2019 Online Issn: 1943-2674 Print Issn: 0016-7606 © 2019 Geological Society of America GSA Bulletin (2019) 131 (7-8): 1075–1094. https://doi.org/10.1130/B35017.1 Article history Received: 24 Apr 2018 Revision Received: 01 Oct 2018 Accepted: 01 Nov 2018 First Online: 06 Feb 2019 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Keith Dewing, Thomas Hadlari, D. Graham Pearson, William Matthews; Early Ordovician to Early Devonian tectonic development of the northern margin of Laurentia, Canadian Arctic Islands. GSA Bulletin 2019;; 131 (7-8): 1075–1094. doi: https://doi.org/10.1130/B35017.1 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 SocietyGSA Bulletin Search Advanced Search Abstract Three tectonic events affected the northern margin of Laurentia between Early Ordovician and Early Devonian time. Each tectonic cycle started with an unconformity followed by rapid subsidence and an influx of clastic material, then decreasing sediment accumulation rates. The first cycle extends from the Tremadoc to late Katian (480–448 Ma), the second from late Katian to Ludlow (448–426 Ma), and the third from Ludlow to Lochkovian (426–410 Ma).A strong geodynamic link is interpreted between the first two sedimentary cycles and tectonic events on the composite Pearya terrane on northern Ellesmere Island, Nunavut, Canada. The first cycle is interpreted as a response to crustal thickening caused by the M'Clintock Orogeny on Pearya terrane and onset of subduction dipping under Laurentia. An extensive Middle Ordovician (Darriwillian) unconformity is not associated with a change in subsidence rate or a change of facies above and below, but is normally faulted. It is interpreted as a migrating forebulge or increase in crustal buoyancy due to breakoff of a subduction slab.The second cycle is synchronous with a Late Ordovician minor faulting event on Pearya terrane and volcanic units in the deep water basin between Pearya terrane and the carbonate platform. A major platform margin stepback, along with a positive εNd shift are associated with the late Katian Irene Bay Formation. The event also introduced numerous organisms of Siberian affinity into northern Laurentia. The third cycle, starting in Ludlow time is related to the onset of deformation in the Boothia foldbelt and is not recorded as a deformational event on Pearya terrane.The presence of aerially restricted intraplatform basins that are interpreted to be synchronous with, and caused by, tectonic events on Pearya terrane implies that it was close to its current location by Early Ordovician time. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.