Paleowinds inferred from detrital-zircon geochronology of upper Paleozoic loessite, western equatorial Pangea

Research Article| August 01, 2002 Paleowinds inferred from detrital-zircon geochronology of upper Paleozoic loessite, western equatorial Pangea Michael J. Soreghan; Michael J. Soreghan 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA Search for other works by this author on: GSW Google Scholar G.S. (Lynn) Soreghan; G.S. (Lynn) Soreghan 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA Search for other works by this author on: GSW Google Scholar Michael A. Hamilton Michael A. Hamilton 2J.C. Roddick Ion Microprobe (SHRIMP II) Laboratory, Continental Geoscience Division, Geological Survey of Canada, Ottawa, Ontario K1A OE8, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Michael J. Soreghan 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA G.S. (Lynn) Soreghan 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73019, USA Michael A. Hamilton 2J.C. Roddick Ion Microprobe (SHRIMP II) Laboratory, Continental Geoscience Division, Geological Survey of Canada, Ottawa, Ontario K1A OE8, Canada Publisher: Geological Society of America Received: 11 Jan 2002 Revision Received: 12 Apr 2002 Accepted: 16 Apr 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (8): 695–698. https://doi.org/10.1130/0091-7613(2002)030<0695:PIFDZG>2.0.CO;2 Article history Received: 11 Jan 2002 Revision Received: 12 Apr 2002 Accepted: 16 Apr 2002 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 Michael J. Soreghan, G.S. (Lynn) Soreghan, Michael A. Hamilton; Paleowinds inferred from detrital-zircon geochronology of upper Paleozoic loessite, western equatorial Pangea. Geology 2002;; 30 (8): 695–698. doi: https://doi.org/10.1130/0091-7613(2002)030<0695:PIFDZG>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 U-Pb geochronology of detrital zircons from upper Paleozoic loessite (western United States) provides data bearing on atmospheric circulation within western equatorial Pangea. Zircon age spectra of four loessites from three localities representing middle Pennsylvanian (Desmoinesian) and Early Permian (Wolfcampian) time vary significantly, reflecting changing provenances attributable to temporal and spatial shifts in winds. Zircons from two Desmoinesian samples (from Arizona and Utah) show a dominant mode between 1800 and 1600 Ma, reflecting the Yavapai-Mazatzal terranes that cored the Ancestral Rockies uplifts and suggesting northeasterly winds. Both samples also contain a secondary cluster of Grenvillian grains (1300–1000 Ma), reflecting a south-southeasterly source. Ages for Wolfcampian samples (from New Mexico and Utah) differ from one another; the New Mexico loessite contains a large mode at 1700 Ma, missing in the Utah sample, reflecting their locations on opposing sides of the Ancestral Rocky Mountains, within a westerly wind regime. Inferred easterly winds for middle Pennsylvanian time match model predictions, and the presence of both northerly and southerly directions might reflect time-averaged fluctuation of the Inter-Tropical Convergence Zone. In contrast, monsoonal circulation and attendant westerly winds appear to have been well established by earliest Permian time. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.