Oroclines: Thick and thin

Research Article| May 01, 2013 Oroclines: Thick and thin S.T. Johnston; S.T. Johnston † 1School of Earth & Ocean Sciences, University of Victoria, P.O. Box 3065 STN CSC, Victoria, British Columbia V8P 4B2, Canada †E-mail: stj@uvic.ca Search for other works by this author on: GSW Google Scholar A.B. Weil; A.B. Weil 2Department of Geology, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010, USA Search for other works by this author on: GSW Google Scholar G. Gutiérrez-Alonso G. Gutiérrez-Alonso 3Departamento de Geología, Universidad de Salamanca, Plaza de los Caídos s/n, 37008 Salamanca, Spain Search for other works by this author on: GSW Google Scholar Author and Article Information S.T. Johnston † 1School of Earth & Ocean Sciences, University of Victoria, P.O. Box 3065 STN CSC, Victoria, British Columbia V8P 4B2, Canada A.B. Weil 2Department of Geology, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010, USA G. Gutiérrez-Alonso 3Departamento de Geología, Universidad de Salamanca, Plaza de los Caídos s/n, 37008 Salamanca, Spain †E-mail: stj@uvic.ca Publisher: Geological Society of America Received: 18 Jul 2012 Revision Received: 30 Nov 2012 Accepted: 06 Dec 2012 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2013 Geological Society of America GSA Bulletin (2013) 125 (5-6): 643–663. https://doi.org/10.1130/B30765.1 Article history Received: 18 Jul 2012 Revision Received: 30 Nov 2012 Accepted: 06 Dec 2012 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation S.T. Johnston, A.B. Weil, G. Gutiérrez-Alonso; Oroclines: Thick and thin. GSA Bulletin 2013;; 125 (5-6): 643–663. doi: https://doi.org/10.1130/B30765.1 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 An orocline is a thrust belt or orogen that is curved in map-view due to it having been bent or buckled about a vertical axis of rotation. Two distinct types of oroclines are recognized: progressive and secondary. Progressive oroclines are restricted to the scale of a thrust sheet to thrust belt, are thin-skinned, and develop during thrust sheet emplacement. Secondary oroclines are larger, occurring at the scale of an orogen, and are plate-scale features that affect crust and lithospheric mantle. Unlike progressive oroclines, which develop during initial orogenesis and in response to the same orogen-perpendicular stress responsible for thrust sheet emplacement, secondary oroclines are extra-orogenic, developing after initial orogenesis and in response to an orogen-parallel principal compressive stress that is oriented at a high angle to the stress responsible for orogen development. We present case studies of the Wyoming Salient, a progressive orocline that characterizes the Sevier thrust belt of the western United States, and the coupled Cantabrian and Central Iberian oroclines, which are linked secondary oroclines affecting the Variscan orogen of Iberia. The vertical-axis rotations involved in progressive and secondary orocline formation are most readily quantified through paleomagnetic analysis. Detailed three-dimensional palinspastic restoration that incorporates translation rotation and strain can distinguish the role, if any, of primary curvature in progressive oroclines. The use of tectonic vectors, such as paleocurrent directions, provides a means of recognizing and characterizing the initial geometry of secondary oroclines. Because secondary oroclines involve the entire lithosphere, detailed studies of coeval metamorphism and magmatism provide a means of constraining the fate of the mantle lithosphere during oroclinal buckling. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.