Gunbarrel mafic magmatic event: A key 780 Ma time marker for Rodinia plate reconstructions

Abstract

Research Article| December 01, 2003 Gunbarrel mafic magmatic event: A key 780 Ma time marker for Rodinia plate reconstructions Stephen S. Harlan; Stephen S. Harlan 1Department of Environmental Science and Policy, George Mason University, Fairfax, Virginia 22030, USA Search for other works by this author on: GSW Google Scholar Larry Heaman; Larry Heaman 2Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar Anthony N. LeCheminant; Anthony N. LeCheminant 3Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada Search for other works by this author on: GSW Google Scholar Wayne R. Premo Wayne R. Premo 4U.S. Geological Survey, P.O. Box 25046, MS 963, Federal Center, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Stephen S. Harlan 1Department of Environmental Science and Policy, George Mason University, Fairfax, Virginia 22030, USA Larry Heaman 2Department of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta T6G 2E3, Canada Anthony N. LeCheminant 3Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada Wayne R. Premo 4U.S. Geological Survey, P.O. Box 25046, MS 963, Federal Center, Denver, Colorado 80225, USA Publisher: Geological Society of America Received: 18 Jun 2003 Revision Received: 25 Aug 2003 Accepted: 29 Aug 2003 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2003) 31 (12): 1053–1056. https://doi.org/10.1130/G19944.1 Article history Received: 18 Jun 2003 Revision Received: 25 Aug 2003 Accepted: 29 Aug 2003 First Online: 02 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 Stephen S. Harlan, Larry Heaman, Anthony N. LeCheminant, Wayne R. Premo; Gunbarrel mafic magmatic event: A key 780 Ma time marker for Rodinia plate reconstructions. Geology 2003;; 31 (12): 1053–1056. doi: https://doi.org/10.1130/G19944.1 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 Precise U-Pb baddeleyite dating of mafic igneous rocks provides evidence for a widespread and synchronous magmatic event that extended for >2400 km along the western margin of the Neoproterozoic Laurentian craton. U-Pb baddeleyite analyses for eight intrusions from seven localities ranging from the northern Canadian Shield to northwestern Wyoming–southwestern Montana are statistically indistinguishable and yield a composite U-Pb concordia age for this event of 780.3 ± 1.4 Ma (95% confidence level). This 780 Ma event is herein termed the Gunbarrel magmatic event. The mafic magmatism of the Gunbarrel event represents the largest mafic dike swarm yet identified along the Neoproterozoic margin of Laurentia. The origin of the mafic magmatism is not clear, but may be related to mantle-plume activity or upwelling asthenosphere leading to crustal extension accompanying initial breakup of the supercontinent Rodinia and development of the proto– Pacific Ocean. The mafic magmatism of the Gunbarrel magmatic event at 780 Ma predates the voluminous magmatism of the 723 Ma Franklin igneous event of the northwestern Canadian Shield by ∼60 m.y. The precise dating of the extensive Neoproterozoic Gunbarrel and Franklin magmatic events provides unique time markers that can ultimately be used for robust testing of Neoproterozoic continental reconstructions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.