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Archean age for the granulite facies metamorphism near the center of the Vredefort structure, South Africa

1999; Geological Society of America; Volume: 27; Issue: 12 Linguagem: Inglês

10.1130/0091-7613(1999)027 2.3.co;2

1943-2682

Rodger J. Hart, D. E. Moser, M. A. G. Andreoli,

Geological formations and processes

Research Article| December 01, 1999 Archean age for the granulite facies metamorphism near the center of the Vredefort structure, South Africa Rodger Hart; Rodger Hart 1Schonland Research Center, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa Search for other works by this author on: GSW Google Scholar Desmond Moser; Desmond Moser 2Jack Satterly Geochronology Laboratory, Royal Ontario Museum, Toronto M55 2C6, Canada Search for other works by this author on: GSW Google Scholar Marco Andreoli Marco Andreoli 3Atomic Energy Corporation of South Africa, P.O. Box 582, Pretoria 0001, South Africa Search for other works by this author on: GSW Google Scholar Author and Article Information Rodger Hart 1Schonland Research Center, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa Desmond Moser 2Jack Satterly Geochronology Laboratory, Royal Ontario Museum, Toronto M55 2C6, Canada Marco Andreoli 3Atomic Energy Corporation of South Africa, P.O. Box 582, Pretoria 0001, South Africa Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1999) 27 (12): 1091–1094. https://doi.org/10.1130/0091-7613(1999)027 2.3.CO;2 Article history 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 Rodger Hart, Desmond Moser, Marco Andreoli; Archean age for the granulite facies metamorphism near the center of the Vredefort structure, South Africa. Geology 1999;; 27 (12): 1091–1094. doi: https://doi.org/10.1130/0091-7613(1999)027 2.3.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 Granulite facies metamorphic assemblages in rocks exposed near the center of the 2.02 Ga Vredefort impact structure previously have been interpreted either as Early Proterozoic, genetically related to the 2060 Ma Bushveld Complex, or as Archean, and representative of lower crust that rebounded to upper crustal levels following an impact event. Zircon and monazite recovered from the granulite facies rocks record high-grade metamorphism at 3107 ± 9 Ma and a primary age of ≥ 3425 Ma for detrital zircon. A shock-deformed, but otherwise pristine, dolerite dike that intrudes the granulite terrane yields a U-Pb zircon age of ≥ 2560 Ma, providing a minimum age for the metamorphism. These isotopic age data are difficult to reconcile with a regional high-grade metamorphic event in the crust beneath Vredefort at 2060 Ma. Instead, the preimpact, high-temperature metamorphic history observed in the Vredefort lower crustal rocks indicates an enigmatic high-temperature event during the stabilization of diamondiferous Archean tectosphere. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.