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Calcareous nannofossils at the K-T boundary, El Kef: No evidence for stepwise, gradual, or sequential extinctions

1994; Geological Society of America; Volume: 22; Issue: 2 Linguagem: Inglês

10.1130/0091-7613(1994)022 2.3.co;2

1943-2682

James J. Pospichal,

Geological formations and processes

Research Article| February 01, 1994 Calcareous nannofossils at the K-T boundary, El Kef: No evidence for stepwise, gradual, or sequential extinctions James J. Pospichal James J. Pospichal 1Antarctic Marine Geology Research Facility, Florida State University, Tallahassee, Florida 32306 Search for other works by this author on: GSW Google Scholar Author and Article Information James J. Pospichal 1Antarctic Marine Geology Research Facility, Florida State University, Tallahassee, Florida 32306 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1994) 22 (2): 99–102. https://doi.org/10.1130/0091-7613(1994)022 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 Email Permissions Search Site Citation James J. Pospichal; Calcareous nannofossils at the K-T boundary, El Kef: No evidence for stepwise, gradual, or sequential extinctions. Geology 1994;; 22 (2): 99–102. doi: https://doi.org/10.1130/0091-7613(1994)022 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 detailed quantitative study of well-preserved nannofossil assemblages in closely spaced samples across the Cretaceous-Tertiary (K-T) boundary at El Kef, Tunisia, reveals no extinctions of nannoplankton in the uppermost 4 m of Maastrichtian marls as has been reported for planktonic foraminifers from the same samples. Nannofossil assemblages below the boundary show no trends to indicate that ecologic stresses such as temperature change foreshadowed the K-T event in the Tethyan region. On the other hand, the disappearance of several species of the more depth-sensitive planktonic foraminifers below the boundary at El Kef is probably the result of sea-level regression (or sampling effects) rather than preboundary climate change or other environmental stresses. Cretaceous nannofossil specimens present above the K-T boundary at El Kef are interpreted to have been reworked, rather than having survived the K-T event. This interpretation is suggested by abundance patterns of common Cretaceous species and a correlation with short-term sea-level lowstands. 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.