Absolute Chronology of the Late Neogene Calcareous Nannofossil Succession in the Equatorial Pacific

Abstract

Research Article| June 01, 1973 Absolute Chronology of the Late Neogene Calcareous Nannofossil Succession in the Equatorial Pacific STEFAN GARTNER STEFAN GARTNER 1School of Marine and Atmospheric Science, 10 Rickenbacker Causeway, University of Miami, Miami, Florida 33149 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1973) 84 (6): 2021–2034. https://doi.org/10.1130/0016-7606(1973)84<2021:ACOTLN>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation STEFAN GARTNER; Absolute Chronology of the Late Neogene Calcareous Nannofossil Succession in the Equatorial Pacific. GSA Bulletin 1973;; 84 (6): 2021–2034. doi: https://doi.org/10.1130/0016-7606(1973)84<2021:ACOTLN>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 SocietyGSA Bulletin Search Advanced Search Abstract A continuous pelagic record of the late Neogene was studied in four deep-sea cores for which the magnetic stratigraphy had been worked out previously. Within the past 8 m.y., eleven distinctive calcareous nannofossil datum levels are recognizable, and these are related to the absolute chronology of the magnetic time scale. Two datum levels are recognizable within the late Pleistocene, at about 170,000 and 350,000 yrs B.P. The earlier Pleistocene did not yield comparable marker species. The Pliocene-Pleistocene boundary, which is correlated on the geomagnetic scale with the base of the Olduvai event within the Matuyama reversed epoch, is closely approximated by the extinction of the last true discoaster species at about 1.8 m.y. B.P. Within the Pliocene, six datum levels are recognized, and correlation with Mediterranean Pliocene deposits indicates an age of about 5 m.y. for the Miocene-Pliocene boundary. The uppermost Miocene seems to be devoid of distinctive markers, but this may be due to inadequate data.Of the many nannoplankton which became extinct in the late Neogene, only two species, Cydococcolithina macintyrei and Discoaster brouweri, have their last occurrence near a magnetic reversal, and of these the extinction of Discoaster brouweri probably cannot be related to a magnetic reversal. It appears, therefore, that calcareous nannoplankters were not adversely affected by collapse or reversals in the Earth's magnetic field. 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.