New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes
The Middle Eocene Climatic Optimum (MECO) was a warming event that interrupted the long-term Eocene cooling trend. While this event is well documented at high southern and mid-latitudes, it is poorly known from low latitudes and its timing and duration are not well constrained because of problems of...
Published in: | Palaeogeography, Palaeoclimatology, Palaeoecology |
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Main Authors: | , , , , , |
Format: | Article in Journal/Newspaper |
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Elsevier
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Online Access: | https://orca.cardiff.ac.uk/id/eprint/10024/ https://doi.org/10.1016/j.palaeo.2010.09.016 |
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:10024 2023-05-15T18:01:06+02:00 New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes Edgar, Kirsty M. Wilson, Paul A. Sexton, Philip F. Gibbs, S. J. Roberts, A. P. Norris, R. D. 2010 https://orca.cardiff.ac.uk/id/eprint/10024/ https://doi.org/10.1016/j.palaeo.2010.09.016 unknown Elsevier Edgar, Kirsty M., Wilson, Paul A., Sexton, Philip F., Gibbs, S. J., Roberts, A. P. and Norris, R. D. 2010. New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes. Palaeogeography, Palaeoclimatology, Palaeoecology 297 (3-4) , pp. 670-682. 10.1016/j.palaeo.2010.09.016 https://doi.org/10.1016/j.palaeo.2010.09.016 doi:10.1016/j.palaeo.2010.09.016 GC Oceanography QE Geology Article PeerReviewed 2010 ftunivcardiff https://doi.org/10.1016/j.palaeo.2010.09.016 2022-09-25T20:17:25Z The Middle Eocene Climatic Optimum (MECO) was a warming event that interrupted the long-term Eocene cooling trend. While this event is well documented at high southern and mid-latitudes, it is poorly known from low latitudes and its timing and duration are not well constrained because of problems of hiati, microfossil preservation and weak magnetic polarity in key sedimentary sections. Here, we report the results of a study designed to improve the bio-, magneto- and chemostratigraphy of the MECO interval using high-resolution records from two low-latitude sections in the Atlantic Ocean, Ocean Drilling Program (ODP) Sites 1051 and 1260. We present the first detailed benthic foraminiferal stable isotope records of the MECO from the low latitudes as well as the biostratigraphic counts of Orbulinoides beckmanni and new magnetostratigraphic results. Our data demonstrate a ~ 750 kyr-long duration for the MECO characterized by increasing δ13C and decreasing δ18O, with minimum δ18O values lasting ~ 40 kyr at 40.1 Ma coincident with a short-lived negative δ13C excursion. Thereafter, δ18O and δ13C values recover rapidly. The shift to minimum δ18O values at 40.1 Ma is coincident with a marked increase in the abundance of the planktonic foraminifera O. beckmanni, consistent with its inferred warm-water preference. O. beckmanni is an important Eocene biostratigraphic marker, defining planktonic foraminiferal Zone E12 with its lowest and highest occurrences (LO and HOs). Our new records reveal that the LO of O. beckmanni is distinctly diachronous, appearing ~ 500 kyr earlier in the equatorial Atlantic than in the subtropics (40.5 versus 41.0 Ma). We also show that, at both sites, the HO of O. beckmanni at 39.5 Ma is younger than the published calibrations, increasing the duration of Zone E12 by at least 400 kyr. In accordance with the tropical origins of O. beckmanni, this range expansion to higher latitudes may have occurred in response to sea surface warming during the MECO and subsequently disappeared with cooling of ... Article in Journal/Newspaper Planktonic foraminifera Cardiff University: ORCA (Online Research @ Cardiff) Palaeogeography, Palaeoclimatology, Palaeoecology 297 3-4 670 682 |
institution |
Open Polar |
collection |
Cardiff University: ORCA (Online Research @ Cardiff) |
op_collection_id |
ftunivcardiff |
language |
unknown |
topic |
GC Oceanography QE Geology |
spellingShingle |
GC Oceanography QE Geology Edgar, Kirsty M. Wilson, Paul A. Sexton, Philip F. Gibbs, S. J. Roberts, A. P. Norris, R. D. New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes |
topic_facet |
GC Oceanography QE Geology |
description |
The Middle Eocene Climatic Optimum (MECO) was a warming event that interrupted the long-term Eocene cooling trend. While this event is well documented at high southern and mid-latitudes, it is poorly known from low latitudes and its timing and duration are not well constrained because of problems of hiati, microfossil preservation and weak magnetic polarity in key sedimentary sections. Here, we report the results of a study designed to improve the bio-, magneto- and chemostratigraphy of the MECO interval using high-resolution records from two low-latitude sections in the Atlantic Ocean, Ocean Drilling Program (ODP) Sites 1051 and 1260. We present the first detailed benthic foraminiferal stable isotope records of the MECO from the low latitudes as well as the biostratigraphic counts of Orbulinoides beckmanni and new magnetostratigraphic results. Our data demonstrate a ~ 750 kyr-long duration for the MECO characterized by increasing δ13C and decreasing δ18O, with minimum δ18O values lasting ~ 40 kyr at 40.1 Ma coincident with a short-lived negative δ13C excursion. Thereafter, δ18O and δ13C values recover rapidly. The shift to minimum δ18O values at 40.1 Ma is coincident with a marked increase in the abundance of the planktonic foraminifera O. beckmanni, consistent with its inferred warm-water preference. O. beckmanni is an important Eocene biostratigraphic marker, defining planktonic foraminiferal Zone E12 with its lowest and highest occurrences (LO and HOs). Our new records reveal that the LO of O. beckmanni is distinctly diachronous, appearing ~ 500 kyr earlier in the equatorial Atlantic than in the subtropics (40.5 versus 41.0 Ma). We also show that, at both sites, the HO of O. beckmanni at 39.5 Ma is younger than the published calibrations, increasing the duration of Zone E12 by at least 400 kyr. In accordance with the tropical origins of O. beckmanni, this range expansion to higher latitudes may have occurred in response to sea surface warming during the MECO and subsequently disappeared with cooling of ... |
format |
Article in Journal/Newspaper |
author |
Edgar, Kirsty M. Wilson, Paul A. Sexton, Philip F. Gibbs, S. J. Roberts, A. P. Norris, R. D. |
author_facet |
Edgar, Kirsty M. Wilson, Paul A. Sexton, Philip F. Gibbs, S. J. Roberts, A. P. Norris, R. D. |
author_sort |
Edgar, Kirsty M. |
title |
New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes |
title_short |
New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes |
title_full |
New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes |
title_fullStr |
New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes |
title_full_unstemmed |
New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes |
title_sort |
new biostratigraphic, magnetostratigraphic and isotopic insights into the middle eocene climatic optimum in low latitudes |
publisher |
Elsevier |
publishDate |
2010 |
url |
https://orca.cardiff.ac.uk/id/eprint/10024/ https://doi.org/10.1016/j.palaeo.2010.09.016 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_relation |
Edgar, Kirsty M., Wilson, Paul A., Sexton, Philip F., Gibbs, S. J., Roberts, A. P. and Norris, R. D. 2010. New biostratigraphic, magnetostratigraphic and isotopic insights into the Middle Eocene Climatic Optimum in low latitudes. Palaeogeography, Palaeoclimatology, Palaeoecology 297 (3-4) , pp. 670-682. 10.1016/j.palaeo.2010.09.016 https://doi.org/10.1016/j.palaeo.2010.09.016 doi:10.1016/j.palaeo.2010.09.016 |
op_doi |
https://doi.org/10.1016/j.palaeo.2010.09.016 |
container_title |
Palaeogeography, Palaeoclimatology, Palaeoecology |
container_volume |
297 |
container_issue |
3-4 |
container_start_page |
670 |
op_container_end_page |
682 |
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1766170445305872384 |