Planktic foraminiferal turnover across the Paleocene-Eocene transition at (DSDP) Site 401, Bay of Biscay, North Atlantic

TitlePlanktic foraminiferal turnover across the Paleocene-Eocene transition at (DSDP) Site 401, Bay of Biscay, North Atlantic
Publication TypeJournal Article
Year of Publication1997
AuthorsPardo, A, Keller, G, Molina, E, Canudo, JI
JournalMarine Micropaleontology
Volume29
Pagination129–158
Date Publishedjan
Abstract

Planktic foraminifera across the Paleocene-Eocene transition at DSDP Site 401 indicate that the benthic foraminiferal mass extinction occurred within Subzone P 6a of Berggren and Miller (1988), or P5 of Berggren et al. (1995) and coincident with a sudden 2.0%. excursion in δ13C values. The benthic foraminiferal extinction event (BFEE) and δ13Cexcursion was accompanied by a planktic foraminiferal turnover marked by an influx of warm water species (Morozovella and Acarinina), a decrease in cooler water species (Subbotina), a sudden short-term increase in low oxygen tolerant taxa (Chiloguembelina), and no significant species extinctions. These faunal changes suggest climatic warming, expansion of the oxygen minimum zone, and a well stratified ocean water column. Oxygen isotope data of the surface dweller M. subbotina suggest climate warming beginning with a gradual 0.5%. decrease in δ18O in the 175 cm preceding the benthic foraminiferal extinction event followed by a sudden decrease of 1%. (4 °C) at the BFEE. The δ13C excursion occurred over 27 cm of sediment and, assuming constant sediment accumulation rates, represents a maximum of 23 ka. Recovery to pre-excursion gd13C values occurs within 172 cm, or about 144 ka. Climate cooling begins in Subzone P 6c as indicated by an increase in cooler water subbotinids and acarininids with rounded chambers and a decrease in warm water morozovellids.  PDF

URLhttps://doi.org/10.1016/s0377-8398(96)00035-7
DOI10.1016/s0377-8398(96)00035-7