Synchroneity of the K-T oceanic mass extinction and meteorite impact: Blake Nose, western North Atlantic

Research Article| May 01, 1999 Synchroneity of the K-T oceanic mass extinction and meteorite impact: Blake Nose, western North Atlantic R. D. Norris; R. D. Norris 1MS-23, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543-1541, USA Search for other works by this author on: GSW Google Scholar B. T. Huber; B. T. Huber 2Department of Paleobiology, Smithsonian Institution, Washington, D.C. 20560, USA Search for other works by this author on: GSW Google Scholar J. Self-Trail J. Self-Trail 3U.S. Geological Survey, 926A National Center, Reston, Virginia 20192, USA Search for other works by this author on: GSW Google Scholar Author and Article Information R. D. Norris 1MS-23, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543-1541, USA B. T. Huber 2Department of Paleobiology, Smithsonian Institution, Washington, D.C. 20560, USA J. Self-Trail 3U.S. Geological Survey, 926A National Center, Reston, Virginia 20192, USA 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 (5): 419–422. https://doi.org/10.1130/0091-7613(1999)027<0419:SOTKTO>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 R. D. Norris, B. T. Huber, J. Self-Trail; Synchroneity of the K-T oceanic mass extinction and meteorite impact: Blake Nose, western North Atlantic. Geology 1999;; 27 (5): 419–422. doi: https://doi.org/10.1130/0091-7613(1999)027<0419:SOTKTO>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 A 10-cm-thick layer of green spherules occurs precisely at the biostratigraphic boundary between the Cretaceous and Paleogene (K-T boundary) at Ocean Drilling Program Site 1049 (lat 30°08′N, long 76°06′W). The spherulitic layer contains abundant rock fragments (chalk, limestone, dolomite, chert, mica books, and schist) as well as shocked quartz, abundant large Cretaceous planktic foraminifera, and rounded clasts of clay as long as 4 mm interpreted as altered tektite glass probably derived from the Chicxulub impact structure. Most of the Cretaceous foraminifera present above the spherule layer are not survivors since small specimens are conspicuously rare compared to large individuals. Instead, the Cretaceous taxa in Paleocene sediments are thought to be reworked. The first Paleocene planktic foraminifera and calcareous nannofossil species are recorded immediately above the spherule bed, the upper part of which contains an iridium anomaly. Hence, deposition of the impact ejecta exactly coincided with the biostratigraphic K-T boundary and demonstrates that the impact event was synchronous with the evolutionary turnover in the oceans. These results are consistent with a reanalysis of the biostratigraphy of the K-T boundary stratotype, which argues that shallow-marine K-T boundary sections are not biostratigraphically more complete than deep-sea K-T boundary sites. 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.