Academic Commons

Articles

Pliocene-Pleistocene radiolarian events and magnetostratigraphic calibrations for the tropical Indian Ocean

Johnson, David A.; Schneider, David A.; Nigrini, Catherine A.; Caulet, Jean Pierre; Kent, Dennis V.

A composite of four piston cores from the Central Indian Basin and adjacent Ninetyeast Ridge has yielded a continuous magnetobiostratigraphic reference section for most of the Pliocene and the Pleistocene (0.0–4.5 Ma). We identified thirty-three radiolarian events (first- or last-occurrences), and precisely correlated each event to the Neogene geomagnetic polarity time scale. Thirteen of these events are based on revised taxonomic studies of the genera Anthocyrtidium and Pterocorys. Some events show significant departures from synchroneity: five of the radiolarian first-appearances and seven of the last-appearances are time-transgressive by 0.4 m.y. or greater. We here propose a revised, eleven-fold radiolarian zonation for the Pliocene-Pleistocene, using zonal boundaries defined by events which are easily recognized and are demonstrably synchronous in the tropical Indo-Pacific. The sequence of faunal and floral events reported in this paper will allow high-resolution biostratigraphic correlations within the tropical Indian Ocean; however, the same sequence of events is not necessarily applicable to other tropical or extratropical regions.

Geographic Areas

Files

Also Published In

Title
Marine Micropaleontology
DOI
https://doi.org/10.1016/0377-8398(89)90031-5

More About This Work

Academic Units
Lamont-Doherty Earth Observatory
Published Here
January 13, 2012
Academic Commons provides global access to research and scholarship produced at Columbia University, Barnard College, Teachers College, Union Theological Seminary and Jewish Theological Seminary. Academic Commons is managed by the Columbia University Libraries.