U-Pb zircon date from the Neoproterozoic Ghaub Formation, Namibia: Constraints on Marinoan glaciation

Abstract

Research Article| September 01, 2004 U-Pb zircon date from the Neoproterozoic Ghaub Formation, Namibia: Constraints on Marinoan glaciation K.-H. Hoffmann; K.-H. Hoffmann 1Geological Survey of Namibia, 1 Aviation Road, Windhoek, Namibia Search for other works by this author on: GSW Google Scholar D.J. Condon; D.J. Condon 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar S.A. Bowring; S.A. Bowring 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar J.L. Crowley J.L. Crowley 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Author and Article Information K.-H. Hoffmann 1Geological Survey of Namibia, 1 Aviation Road, Windhoek, Namibia D.J. Condon 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Massachusetts 02139, USA S.A. Bowring 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Massachusetts 02139, USA J.L. Crowley 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Massachusetts 02139, USA Publisher: Geological Society of America Received: 29 Jan 2004 Revision Received: 03 May 2004 Accepted: 17 May 2004 First Online: 03 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2004) 32 (9): 817–820. https://doi.org/10.1130/G20519.1 Article history Received: 29 Jan 2004 Revision Received: 03 May 2004 Accepted: 17 May 2004 First Online: 03 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 K.-H. Hoffmann, D.J. Condon, S.A. Bowring, J.L. Crowley; U-Pb zircon date from the Neoproterozoic Ghaub Formation, Namibia: Constraints on Marinoan glaciation. Geology 2004;; 32 (9): 817–820. doi: https://doi.org/10.1130/G20519.1 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 Dropstone-bearing glaciomarine sedimentary rocks of the Ghaub Formation within metamorphosed Neoproterozoic basinal strata (Swakop Group) in central Namibia contain interbedded mafic lava flows and thin felsic ash beds. U-Pb zircon geochronology of an ash layer constrains the deposition of the glaciomarine sediments to 635.5 ± 1.2 Ma, providing an age for what has been described as a “Marinoan-type” glaciation. In addition, this age provides a maximum limit for the proposed lower boundary of the terminal Proterozoic (Ediacaran) system and period. Combined with reliable age constraints from other Neoproterozoic glacial units—the ca. 713 Ma Gubrah Member (Oman) and the 580 Ma Gaskiers Formation (Newfoundland)—these data provide unequivocal evidence for at least three, temporally discrete, glacial episodes during Neoproterozoic time with interglacial periods, characterized by prolonged positive δ13C excursions, lasting at most ∼50– 80 m.y. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.