Re-Os isotope and geochemical study of the Vredefort Granophyre: Clues to the origin of the Vredefort structure, South Africa

Abstract

Research Article| October 01, 1996 Re-Os isotope and geochemical study of the Vredefort Granophyre: Clues to the origin of the Vredefort structure, South Africa Christian Koeberl; Christian Koeberl 1Institute of Geochemistry, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria Search for other works by this author on: GSW Google Scholar Wolf Uwe Reimold; Wolf Uwe Reimold 2Department of Geology, University of the Witwatersrand, Johannesburg 2050, South Africa Search for other works by this author on: GSW Google Scholar Steven B. Shirey Steven B. Shirey 3Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, D.C. 20015 Search for other works by this author on: GSW Google Scholar Author and Article Information Christian Koeberl 1Institute of Geochemistry, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria Wolf Uwe Reimold 2Department of Geology, University of the Witwatersrand, Johannesburg 2050, South Africa Steven B. Shirey 3Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, D.C. 20015 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1996) 24 (10): 913–916. https://doi.org/10.1130/0091-7613(1996)024<0913:ROIAGS>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 Christian Koeberl, Wolf Uwe Reimold, Steven B. Shirey; Re-Os isotope and geochemical study of the Vredefort Granophyre: Clues to the origin of the Vredefort structure, South Africa. Geology 1996;; 24 (10): 913–916. doi: https://doi.org/10.1130/0091-7613(1996)024<0913:ROIAGS>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 The origin of granophyric rock dikes (the Vredefort Granophyre) at the 2 Ga Vredefort structure in South Africa has been controversial. They have been interpreted as either impact melt or igneous intrusions. Most Vredefort Granophyre samples have considerably higher Os contents than the country rocks and 187Re/188Os and 187Os/188Os ratios that scatter about a 2 Ga isochron. Their initial 187Os/188Os ratios (at 2 Ga) overlap the meteoritic data range, indicating that all the granophyre samples contain some meteoritic Os. The Re-Os isotopic composition of the granophyre is significantly different from that of local precursor rocks and indicates that up to 0.2% of a chondritic component could be contained in the granophyre. Our results confirm the interpretation that the Vredefort Granophyre represents an impact melt rock. 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.