Early Mesozoic paleogeography and tectonic evolution of the western United States: Insights from detrital zircon U-Pb geochronology, Blue Mountains Province, northeastern Oregon

Abstract

Research Article| September 01, 2011 Early Mesozoic paleogeography and tectonic evolution of the western United States: Insights from detrital zircon U-Pb geochronology, Blue Mountains Province, northeastern Oregon Todd A. LaMaskin; Todd A. LaMaskin † 1Department of Geological Sciences, University of Oregon, 1272 University of Oregon, Eugene, Oregon 97403-1272, USA †E-mail: [e-mail] Search for other works by this author on: GSW Google Scholar Jeffrey D. Vervoort; Jeffrey D. Vervoort 2School of Earth and Environmental Sciences, Washington State University, Pullman, Washington 99164-2812, USA Search for other works by this author on: GSW Google Scholar Rebecca J. Dorsey; Rebecca J. Dorsey 1Department of Geological Sciences, University of Oregon, 1272 University of Oregon, Eugene, Oregon 97403-1272, USA Search for other works by this author on: GSW Google Scholar James E. Wright James E. Wright 3Department of Geology, University of Georgia, 308 Geography-Geology Building, 210 Field Street, Athens, Georgia 30602-2501, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Todd A. LaMaskin † 1Department of Geological Sciences, University of Oregon, 1272 University of Oregon, Eugene, Oregon 97403-1272, USA Jeffrey D. Vervoort 2School of Earth and Environmental Sciences, Washington State University, Pullman, Washington 99164-2812, USA Rebecca J. Dorsey 1Department of Geological Sciences, University of Oregon, 1272 University of Oregon, Eugene, Oregon 97403-1272, USA James E. Wright 3Department of Geology, University of Georgia, 308 Geography-Geology Building, 210 Field Street, Athens, Georgia 30602-2501, USA †E-mail: [e-mail] Publisher: Geological Society of America Received: 29 Jan 2010 Revision Received: 29 Sep 2010 Accepted: 29 Oct 2010 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2011 Geological Society of America GSA Bulletin (2011) 123 (9-10): 1939–1965. https://doi.org/10.1130/B30260.1 Article history Received: 29 Jan 2010 Revision Received: 29 Sep 2010 Accepted: 29 Oct 2010 First Online: 08 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 Todd A. LaMaskin, Jeffrey D. Vervoort, Rebecca J. Dorsey, James E. Wright; Early Mesozoic paleogeography and tectonic evolution of the western United States: Insights from detrital zircon U-Pb geochronology, Blue Mountains Province, northeastern Oregon. GSA Bulletin 2011;; 123 (9-10): 1939–1965. doi: https://doi.org/10.1130/B30260.1 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 This study assesses early Mesozoic provenance linkages and paleogeographic-tectonic models for the western United States based on new petrographic and detrital zircon data from Triassic and Jurassic sandstones of the "Izee" and Olds Ferry terranes of the Blue Mountains Province, northeastern Oregon. Triassic sediments were likely derived from the Baker terrane offshore accretionary subduction complex and are dominated by Late Archean (ca. 2.7–2.5 Ga), Late Paleoproterozoic (ca. 2.2–1.6 Ga), and Paleozoic (ca. 380–255 Ma) detrital zircon grains. These detrital ages suggest that portions of the Baker terrane have a genetic affinity with other Cordilleran accretionary subduction complexes of the western United States, including those in the Northern Sierra and Eastern Klamath terranes. The abundance of Precambrian grains in detritus derived from an offshore complex highlights the importance of sediment reworking. Jurassic sediments are dominated by Mesozoic detrital ages (ca. 230–160 Ma), contain significant amounts of Paleozoic (ca. 290, 380–350, 480–415 Ma), Neoproterozoic (ca. 675–575 Ma), and Mesoproterozoic grains (ca. 1.4–1.0 Ga), and have lesser quantities of Late Paleoproterozoic grains (ca. 2.1–1.7 Ga). Detrital zircon ages in Jurassic sediments closely resemble well-documented age distributions in transcontinental sands of Ouachita-Appalachian provenance that were transported across the southwestern United States and modified by input from cratonal, miogeoclinal, and Cordilleran-arc sources during Triassic and Jurassic time. Jurassic sediments likely were derived from the Cordilleran arc and an orogenic highland in Nevada that yielded recycled sand from uplifted Triassic backarc basin deposits. Our data suggest that numerous Jurassic Cordilleran basins formed close to the Cordilleran margin and support a model for moderate post-Jurassic translation (∼400 km) of the Blue Mountains Province. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.