Neoproterozoic biotic diversification: Snowball Earth or aftermath of the Acraman impact?

Abstract

Research Article| May 01, 2003 Neoproterozoic biotic diversification: Snowball Earth or aftermath of the Acraman impact? Kathleen Grey; Kathleen Grey 1Department of Industry and Resources, Geological Survey of Western Australia, 100 Plain Street, East Perth, Western Australia 6004, Australia Search for other works by this author on: GSW Google Scholar Malcolm R. Walter; Malcolm R. Walter 2Australian Centre for Astrobiology, Macquarie University, New South Wales 2901, Australia Search for other works by this author on: GSW Google Scholar Clive R. Calver Clive R. Calver 3Mineral Resources Tasmania, P.O. Box 56, Rosny Park, Tasmania 7018, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information Kathleen Grey 1Department of Industry and Resources, Geological Survey of Western Australia, 100 Plain Street, East Perth, Western Australia 6004, Australia Malcolm R. Walter 2Australian Centre for Astrobiology, Macquarie University, New South Wales 2901, Australia Clive R. Calver 3Mineral Resources Tasmania, P.O. Box 56, Rosny Park, Tasmania 7018, Australia Publisher: Geological Society of America Received: 25 Oct 2002 Revision Received: 31 Jan 2003 Accepted: 04 Feb 2003 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2003) 31 (5): 459–462. https://doi.org/10.1130/0091-7613(2003)031<0459:NBDSEO>2.0.CO;2 Article history Received: 25 Oct 2002 Revision Received: 31 Jan 2003 Accepted: 04 Feb 2003 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 Kathleen Grey, Malcolm R. Walter, Clive R. Calver; Neoproterozoic biotic diversification: Snowball Earth or aftermath of the Acraman impact?. Geology 2003;; 31 (5): 459–462. doi: https://doi.org/10.1130/0091-7613(2003)031<0459:NBDSEO>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 Biostratigraphic and chemostratigraphic studies of Australian late Neoproterozoic (Ediacarian) fossil plankton (acritarch) successions reveal a striking relationship between a radical palynofloral change, a short-lived negative excursion in the carbon isotope composition of kerogen, and a debris layer from the ca. 580 Ma Acraman bolide impact event. Palynomorphs changed from an assemblage dominated by long-ranging, simple spheroids to a much more diverse assemblage characterized by short-ranging, large, complex, process-bearing (acanthomorph) acritarchs, with the first appearance of 57 species. A marked negative carbon isotope excursion was followed by a steady rise coinciding with acanthomorph radiation. There are no apparent sedimentological controls on this radiation. Although the snowball Earth hypothesis predicts postglacial biotic change, radiation did not happen until long after the Marinoan glaciation and not until a second postglacial transgression. We propose that a global extinction and recovery event may have been associated with the Acraman bolide impact. Indications are that the Acraman event could rank with similar Phanerozoic major impact events. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.