Shrinking of the Colorado Plateau via lithospheric mantle erosion: Evidence from Nd and Sr isotopes and geochronology of Neogene basalts

Research Article| January 01, 2011 Shrinking of the Colorado Plateau via lithospheric mantle erosion: Evidence from Nd and Sr isotopes and geochronology of Neogene basalts Ryan Crow; Ryan Crow 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Search for other works by this author on: GSW Google Scholar Karl Karlstrom; Karl Karlstrom 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Search for other works by this author on: GSW Google Scholar Yemane Asmerom; Yemane Asmerom 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Search for other works by this author on: GSW Google Scholar Brandon Schmandt; Brandon Schmandt 2Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA Search for other works by this author on: GSW Google Scholar Victor Polyak; Victor Polyak 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Search for other works by this author on: GSW Google Scholar S. Andrew DuFrane S. Andrew DuFrane 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Ryan Crow 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Karl Karlstrom 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Yemane Asmerom 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Brandon Schmandt 2Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA Victor Polyak 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA S. Andrew DuFrane 1Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131, USA Publisher: Geological Society of America Received: 23 Jul 2010 Accepted: 02 Aug 2010 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2011 Geological Society of America Geology (2011) 39 (1): 27–30. https://doi.org/10.1130/G31611.1 Article history Received: 23 Jul 2010 Accepted: 02 Aug 2010 First Online: 09 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 Ryan Crow, Karl Karlstrom, Yemane Asmerom, Brandon Schmandt, Victor Polyak, S. Andrew DuFrane; Shrinking of the Colorado Plateau via lithospheric mantle erosion: Evidence from Nd and Sr isotopes and geochronology of Neogene basalts. Geology 2011;; 39 (1): 27–30. doi: https://doi.org/10.1130/G31611.1 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 Geochronologic data from the southern margins of the Colorado Plateau (western United States) show an inboard radial migration of Neogene basaltic magmatism. Nd and Sr isotopic data show that as basaltic volcanism migrates inboard it also becomes increasingly more asthenospheric. Strongly asthenospheric alkali basalt (εNd > 4) appeared on the western plateau margin ca. 5 Ma, on the southeastern margin at 7 Ma, and is lacking from the plateau's other margins. Tomographic data suggest that low-velocity mantle underlies almost all recent (younger than 1 Ma) basaltic volcanism in a ring around much of the Colorado Plateau at a depth of 80 km. The combined isotopic and tomographic data indicate that the low-velocity mantle is asthenosphere along the western and southeastern margins of the plateau, but modified lithosphere around the remaining margins. Temporal and spatial patterns suggest a process by which upwelling asthenosphere is progressively infiltrating and replacing lithospheric mantle, especially where Proterozoic boundaries exist. This model explains (1) the dramatic velocity contrast seen well inboard of the physiographic edge of the plateau, (2) the inboard sweep of Neogene magmatism, and (3) isotopic evidence that much (but not all) of the low-velocity mantle is asthenospheric. These data support models that ongoing uplift of the edges of the Colorado Plateau is driven by mantle processes. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.