Paleoproterozoic rocks of central Colorado: Accreted arcs or extended older crust?

Abstract

Research Article| November 01, 2001 Paleoproterozoic rocks of central Colorado: Accreted arcs or extended older crust? Barbara M. Hill; Barbara M. Hill 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA Search for other works by this author on: GSW Google Scholar M.E. Bickford M.E. Bickford 1Department of Earth Sciences, Heroy Geology Laboratory, Syracuse University, Syracuse, New York 13244-1070, USA Search for other works by this author on: GSW Google Scholar Geology (2001) 29 (11): 1015–1018. https://doi.org/10.1130/0091-7613(2001)029<1015:PROCCA>2.0.CO;2 Article history received: 15 Mar 2001 rev-recd: 28 Jun 2001 accepted: 09 Jul 2001 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Barbara M. Hill, M.E. Bickford; Paleoproterozoic rocks of central Colorado: Accreted arcs or extended older crust?. Geology 2001;; 29 (11): 1015–1018. doi: https://doi.org/10.1130/0091-7613(2001)029<1015:PROCCA>2.0.CO;2 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 Paleoproterozoic (1770–1735 Ma) bimodal volcanic rocks in central Colorado have been considered to represent southward growth of Laurentia by arc accretion. Although the bimodality of these rocks suggests an extensional continental setting rather than continental or oceanic arcs, there has been little evidence for pre–1800 Ma crust south of the Wyoming craton other than the 1840 ± 1 Ma Elves Chasm pluton in the Upper Granite Gorge of the Grand Canyon, Arizona. We report SHRIMP U-Pb ages of inherited zircons from metarhyolites and plutons in central Colorado that are latest Archean–earliest Proterozoic (2520–2000 Ma) and Trans-Hudson–Penokean (1878–1814 Ma). Associated quartzites contain detrital zircons with mean ages of 1735 Ma, indicating only local derivation. A meta-arkose, however, contains detrital zircons of Trans-Hudson–Penokean and Archean ages. We believe it likely that the 1900–1800 Ma Trans-Hudson–Penokean orogens, including Archean enclaves, extended farther south and west than is currently thought, and were the source of the bimodal volcanic rocks and associated plutons during the period 1770–1700 Ma. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.