Large-volume, low-δ18O rhyolites of the central Snake River Plain, Idaho, USA

Abstract

Research Article| October 01, 2005 Large-volume, low-δ18O rhyolites of the central Snake River Plain, Idaho, USA Scott Boroughs; Scott Boroughs 1 Department of Geology, Washington State University, Pullman, Washington 99164, USA Search for other works by this author on: GSW Google Scholar John Wolff; John Wolff 1 Department of Geology, Washington State University, Pullman, Washington 99164, USA Search for other works by this author on: GSW Google Scholar Bill Bonnichsen; Bill Bonnichsen 2 Idaho Geological Survey, P.O. Box 443014, Moscow, Idaho 83844, USA Search for other works by this author on: GSW Google Scholar Martha Godchaux; Martha Godchaux 2 Idaho Geological Survey, P.O. Box 443014, Moscow, Idaho 83844, USA Search for other works by this author on: GSW Google Scholar Peter Larson Peter Larson 3Department of Geology, Washington State University, Pullman, Washington 99164, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Scott Boroughs 1 Department of Geology, Washington State University, Pullman, Washington 99164, USA John Wolff 1 Department of Geology, Washington State University, Pullman, Washington 99164, USA Bill Bonnichsen 2 Idaho Geological Survey, P.O. Box 443014, Moscow, Idaho 83844, USA Martha Godchaux 2 Idaho Geological Survey, P.O. Box 443014, Moscow, Idaho 83844, USA Peter Larson 3Department of Geology, Washington State University, Pullman, Washington 99164, USA Publisher: Geological Society of America Received: 17 Mar 2005 Revision Received: 09 Jun 2005 Accepted: 23 Jun 2005 First Online: 03 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2005) 33 (10): 821–824. https://doi.org/10.1130/G21723.1 Article history Received: 17 Mar 2005 Revision Received: 09 Jun 2005 Accepted: 23 Jun 2005 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Scott Boroughs, John Wolff, Bill Bonnichsen, Martha Godchaux, Peter Larson; Large-volume, low-δ18O rhyolites of the central Snake River Plain, Idaho, USA. Geology 2005;; 33 (10): 821–824. doi: https://doi.org/10.1130/G21723.1 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 Miocene Bruneau-Jarbidge and adjacent volcanic fields of the central Snake River Plain, southwest Idaho, are dominated by high-temperature rhyolitic tuffs and lavas having an aggregate volume estimated as 7000 km3. Samples from units representing at least 50% of this volume are strongly depleted in 18O, with magmatic feldspar δ18OVSMOW (Vienna standard mean ocean water) values between −1.4‰ and 3.8‰. The magnitude of the 18O depletion and the complete lack of any rhyolites with normal values (7‰–10‰) combine to suggest that assimilation or melting of a caldera block altered by near- contemporaneous hydrothermal activity is unlikely. Instead, we envisage generation of the high-temperature rhyolites by shallow melting of Idaho Batholith rocks, under the influence of the Yellowstone hotspot, affected by Eocene meteoric-hydrothermal events. The seeming worldwide scarcity of strongly 18O-depleted rhyolites may simply reflect a similar scarcity of suitable crustal protoliths. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.