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Paraburdoo spherule layer (Hamersley Basin, Western Australia): Distal ejecta from a fourth large impact near the Archean-Proterozoic boundary

2011; Geological Society of America; Volume: 39; Issue: 4 Linguagem: Inglês

10.1130/g31526.1

1943-2682

S. W. Hassler, Bruce M. Simonson, D. Y. Sumner, Louis Bodin,

Geological formations and processes

Research Article| April 01, 2011 Paraburdoo spherule layer (Hamersley Basin, Western Australia): Distal ejecta from a fourth large impact near the Archean-Proterozoic boundary Scott W. Hassler; Scott W. Hassler 1John F. Kennedy University, Pleasant Hill, California 94523, USA2Geology Department, Oberlin College, Oberlin, Ohio 44074, USA Search for other works by this author on: GSW Google Scholar Bruce M. Simonson; Bruce M. Simonson 2Geology Department, Oberlin College, Oberlin, Ohio 44074, USA Search for other works by this author on: GSW Google Scholar Dawn Y. Sumner; Dawn Y. Sumner 3Geology Department, University of California−Davis, Davis, California 95616, USA Search for other works by this author on: GSW Google Scholar Louis Bodin Louis Bodin 2Geology Department, Oberlin College, Oberlin, Ohio 44074, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Scott W. Hassler 1John F. Kennedy University, Pleasant Hill, California 94523, USA2Geology Department, Oberlin College, Oberlin, Ohio 44074, USA Bruce M. Simonson 2Geology Department, Oberlin College, Oberlin, Ohio 44074, USA Dawn Y. Sumner 3Geology Department, University of California−Davis, Davis, California 95616, USA Louis Bodin 2Geology Department, Oberlin College, Oberlin, Ohio 44074, USA Publisher: Geological Society of America Received: 29 Jun 2010 Revision Received: 27 Oct 2010 Accepted: 07 Nov 2010 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2011 Geological Society of America Geology (2011) 39 (4): 307–310. https://doi.org/10.1130/G31526.1 Article history Received: 29 Jun 2010 Revision Received: 27 Oct 2010 Accepted: 07 Nov 2010 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Scott W. Hassler, Bruce M. Simonson, Dawn Y. Sumner, Louis Bodin; Paraburdoo spherule layer (Hamersley Basin, Western Australia): Distal ejecta from a fourth large impact near the Archean-Proterozoic boundary. Geology 2011;; 39 (4): 307–310. doi: https://doi.org/10.1130/G31526.1 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 We report the discovery of the Paraburdoo spherule layer, which consists entirely of replaced impact-produced melt spherules. It is distal ejecta from a large impact close to the Archean-Proterozoic boundary in the Hamersley Basin of Western Australia. The spherule layer occurs in the Paraburdoo Member of the Wittenoom Formation and was deposited ca. 2.57 Ga (date via U-Pb age interpolation) in a deep shelf environment. The layer consists of microkrystites rich in plagioclase and ferromagnesian crystals, replaced by K-feldspar and a phlogopite-like sheet silicate, respectively. The skeletal textures indicate rapid cooling of a melt with mafic to ultramafic composition and suggest oceanic target rocks. The Paraburdoo spherule layer is 2 cm thick, normally graded, and was probably deposited by suspension settling, as there is no evidence of reworking; it is strikingly similar to the Reivilo spherule layer in the Griqualand West Basin (South Africa), appears to provide a third impact-related high-resolution stratigraphic correlation between these two basins, and points to a high frequency of large impacts around the Archean-Proterozoic boundary. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.