Morphology of the Explorer–Juan de Fuca slab edge in northern Cascadia: Imaging plate capture at a ridge-trench-transform triple junction

Abstract

Research Article| November 01, 2008 Morphology of the Explorer–Juan de Fuca slab edge in northern Cascadia: Imaging plate capture at a ridge-trench-transform triple junction P. Audet; P. Audet 11Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver V6T 1Z4, Canada Search for other works by this author on: GSW Google Scholar M. G. Bostock; M. G. Bostock 11Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver V6T 1Z4, Canada Search for other works by this author on: GSW Google Scholar J.-P. Mercier; J.-P. Mercier 11Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver V6T 1Z4, Canada Search for other works by this author on: GSW Google Scholar J. F. Cassidy J. F. Cassidy 22Pacific Geoscience Center, Geological Survey of Canada, Sidney, British Columbia V8L 4B2, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information P. Audet 11Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver V6T 1Z4, Canada M. G. Bostock 11Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver V6T 1Z4, Canada J.-P. Mercier 11Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver V6T 1Z4, Canada J. F. Cassidy 22Pacific Geoscience Center, Geological Survey of Canada, Sidney, British Columbia V8L 4B2, Canada Publisher: Geological Society of America Received: 01 Apr 2008 Revision Received: 30 Jul 2008 Accepted: 06 Aug 2008 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2008 Geological Society of America Geology (2008) 36 (11): 895–898. https://doi.org/10.1130/G25356A.1 Article history Received: 01 Apr 2008 Revision Received: 30 Jul 2008 Accepted: 06 Aug 2008 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 P. Audet, M. G. Bostock, J.-P. Mercier, J. F. Cassidy; Morphology of the Explorer–Juan de Fuca slab edge in northern Cascadia: Imaging plate capture at a ridge-trench-transform triple junction. Geology 2008;; 36 (11): 895–898. doi: https://doi.org/10.1130/G25356A.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 Explorer plate is a young oceanic microplate that accommodates relative motion between the Pacific, Juan de Fuca, and North America plates near northern Vancouver Island, Canada. The northern limit of Explorer plate–Juan de Fuca subduction and the fate of the slab in northern Cascadia are poorly understood. We use passive teleseismic recordings from an array of POLARIS broadband seismic stations to image crustal and upper mantle structure beneath northern Vancouver Island into the interior of British Columbia. A clear signature of subducted material extends northeast from the Brooks Peninsula at crustal levels, beneath Georgia Strait and the mainland deep into the mantle to 300 km depth. Complexity in slab morphology results from Juan de Fuca ridge subduction and toroidal flow around the slab edge, in agreement with geophysical and geological data. We propose a tectonic model for the Explorer plate in which its separation from the Juan de Fuca plate is caused by the thermomechanical erosion of the slab edge and slab thinning at shallow levels, both of which slow convergence with North America and lead eventually to plate capture. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.