Emplacement of the Kodiak batholith and slab-window migration

Abstract

Research Article| November 01, 2006 Emplacement of the Kodiak batholith and slab-window migration David W. Farris; David W. Farris 1Department of Earth Sciences, University of Southern California, 3651 Trousdale Avenue, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar Peter Haeussler; Peter Haeussler 2U.S. Geological Survey, 4200 University Drive, Anchorage, Alaska 99508, USA Search for other works by this author on: GSW Google Scholar Richard Friedman; Richard Friedman 3Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, British Columbia V6T 1Z4, Canada Search for other works by this author on: GSW Google Scholar Scott R. Paterson; Scott R. Paterson 4Department of Earth Sciences, University of Southern California, 3651 Trousdale Avenue, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar R.W. Saltus; R.W. Saltus 5U.S. Geological Survey, P.O. Box 25046, MS 964, Denver, Colorado 80225, USA Search for other works by this author on: GSW Google Scholar Robert Ayuso Robert Ayuso 6U.S. Geological Survey, 954 National Center, Reston, Virginia 20192, USA Search for other works by this author on: GSW Google Scholar Author and Article Information David W. Farris 1Department of Earth Sciences, University of Southern California, 3651 Trousdale Avenue, Los Angeles, California 90089, USA Peter Haeussler 2U.S. Geological Survey, 4200 University Drive, Anchorage, Alaska 99508, USA Richard Friedman 3Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, British Columbia V6T 1Z4, Canada Scott R. Paterson 4Department of Earth Sciences, University of Southern California, 3651 Trousdale Avenue, Los Angeles, California 90089, USA R.W. Saltus 5U.S. Geological Survey, P.O. Box 25046, MS 964, Denver, Colorado 80225, USA Robert Ayuso 6U.S. Geological Survey, 954 National Center, Reston, Virginia 20192, USA Publisher: Geological Society of America Received: 07 Sep 2004 Revision Received: 18 Apr 2006 Accepted: 30 Apr 2006 First Online: 03 Oct 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2006) 118 (11-12): 1360–1376. https://doi.org/10.1130/B25718.1 Article history Received: 07 Sep 2004 Revision Received: 18 Apr 2006 Accepted: 30 Apr 2006 First Online: 03 Oct 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation David W. Farris, Peter Haeussler, Richard Friedman, Scott R. Paterson, R.W. Saltus, Robert Ayuso; Emplacement of the Kodiak batholith and slab-window migration. GSA Bulletin 2006;; 118 (11-12): 1360–1376. doi: https://doi.org/10.1130/B25718.1 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 The Kodiak batholith is one of the largest, most elongate intrusive bodies in the forearc Sanak-Baranof plutonic belt located in southern Alaska. This belt is interpreted to have formed during the subduction of an oceanic spreading center and the associated migration of a slab window. Individual plutons of the Kodiak batholith track the location and evolution of the underlying slab window. Six U/Pb zircon ages from the axis of the batholith exhibit a northeastward-decreasing age progression of 59.2 ± 0.2 Ma at the southwest end to 58.4 ± 0.2 Ma at the northeast tip. The trench-parallel rate of age progression is within error of the average slab-window migration rate for the entire Sanak-Baranof belt (∼19 cm/yr).Structural relationships, U/Pb ages, and a model of new gravity data indicate that magma from the Kodiak batholith ascended 5–10 km as a northeastward-younging series of 1–8-km-diameter viscoelastic diapirs. Individual plutons ascended by multiple emplacement mechanisms including downward flow, collapse of wall rock, stoping, and diking. Stokes flow xenolith calculations suggest ascent rates of 5–100 m/yr and an effective magmatic viscosity of ≈107–108 Pa s. Pre-existing structural or lithologic heterogeneities did not dominantly control the location of the main batholith. Instead, its location was determined by migration of the slab window at depth. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.