Isochronous last-abundant-appearance datum (LAAD) of the diatom Hemidiscus karstenii in the sub-Antarctic

Abstract

Research Article| April 01, 1978 Isochronous last-abundant-appearance datum (LAAD) of the diatom Hemidiscus karstenii in the sub-Antarctic L. H. Burckle; L. H. Burckle 1Lamont-Doherty Geological Observatory, of Columbia University, Palisades, New York 10964 Search for other works by this author on: GSW Google Scholar D. B. Clarke; D. B. Clarke 1Lamont-Doherty Geological Observatory, of Columbia University, Palisades, New York 10964 Search for other works by this author on: GSW Google Scholar N. J. Shackleton N. J. Shackleton 2Sub-Department of Quaternary Research, Cambridge University, Cambridge, England Search for other works by this author on: GSW Google Scholar Author and Article Information L. H. Burckle 1Lamont-Doherty Geological Observatory, of Columbia University, Palisades, New York 10964 D. B. Clarke 1Lamont-Doherty Geological Observatory, of Columbia University, Palisades, New York 10964 N. J. Shackleton 2Sub-Department of Quaternary Research, Cambridge University, Cambridge, England Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1978) 6 (4): 243–246. https://doi.org/10.1130/0091-7613(1978)6<243:ILDLOT>2.0.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 L. H. Burckle, D. B. Clarke, N. J. Shackleton; Isochronous last-abundant-appearance datum (LAAD) of the diatom Hemidiscus karstenii in the sub-Antarctic. Geology 1978;; 6 (4): 243–246. doi: https://doi.org/10.1130/0091-7613(1978)6<243:ILDLOT>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 The last-abundant-appearance datum (LAAD) of the diatom Hemidiscus karstenii occurs in the upper part of oxygen-isotope stage 7 in the sub-Antarctic region of the Pacific and Indian Oceans. Strong fluctuations in abundance of this species below the datum level and the strong correlation between abundance peaks and radiolarian-derived sea-surface temperatures strongly suggest that this datum level is not an extinction. Rather it is an abrupt isochronous drop in abundance. It is suggested that this species may have become extinct during isotopic stage 6 when its abundances were low or that it retreated to some local niche where it persists to the present. 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.