Newsam, C;
Bown, PR;
Wade, BS;
Jones, HL;
(2017)
Muted calcareous nannoplankton response at the Middle/Late Eocene Turnover event in the western North Atlantic.
Newsletters on Stratigraphy
, 50
(3)
pp. 297-309.
10.1127/nos/2016/0306.
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Abstract
Key extinctions in two major planktonic foraminiferal groups and high taxic turnover in radiolarians have led to the identification of the Middle/Late Eocene Turnover (MLET) and point towards significant palaeoclimatic and/or palaeoceanographic changes at around 38 million years ago. Here we present quantitative calcareous nannofossil data from Ocean Drilling Program Site 1052 (Blake Nose, western North Atlantic) in order to investigate the response of phytoplankton during the MLET. Our data show only minor shifts in taxon abundance, with no strong trends identified through the interval and no nannofossil origination or extinction events associated with the MLET. The assemblages are characterised by the dominance of neritic braarudosphaerids and eurytopic reticulofenestrids. The increased abundance of warm to temperate and mesotrophic nannofossils (Reticulofenestra reticulata, Reticulofenestra bisecta and Coccolithus pelagicus) in and around the MLET occur against a backdrop of cooling, as indicated by oxygen isotopes, suggesting that changing nutrient conditions was the principle driver of these shifts in the nannoplankton assemblage. This is further supported by an increase in radiolarian accumulation rates at this time. The lack of response in the calcareous nannoplankton relative to the zooplanktonic planktonic foraminifera and radiolaria demonstrates the contrasting sensitivity to environmental change in these different plankton groups, with radiolarians showing the highest degree of change at the MLET and the nannoplankton showing little or none.
| Type: | Article |
|---|---|
| Title: | Muted calcareous nannoplankton response at the Middle/Late Eocene Turnover event in the western North Atlantic |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1127/nos/2016/0306 |
| Publisher version: | http://dx.doi.org/10.1127/nos/2016/0306 |
| Language: | English |
| Additional information: | Copyright © 2016 The authors. Open Access: published under the Creative Commons Attribution-NonCommercial 3.0 Unported (CC BY-NC 3.0) licence (https://creativecommons.org/licenses/by-nc/3.0/). |
| Keywords: | Calcareous nannofossils, MLET, palaeoecology, Blake Nose, Ocean Drilling Program, extinction |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1500812 |
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