Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary
To assess the influence of orbital-scale variations on late Oligocene to early Miocene climate and ocean chemistry, high-resolution (similar to 5 kyr) benthic foraminiferal carbon and oxygen isotope and percent coarse fraction time series were constructed for Ocean Drilling Program site 929 on Ceara...
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Digital Commons @ University of South Florida
2000
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Online Access: | https://digitalcommons.usf.edu/msc_facpub/22 https://doi.org/10.1029/1999PA000443 https://digitalcommons.usf.edu/context/msc_facpub/article/1021/viewcontent/Paul_et_al_2000_Paleoceanography.pdf |
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ftusouthflorida:oai:digitalcommons.usf.edu:msc_facpub-1021 2023-07-30T03:58:20+02:00 Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary Paul, Hilary A. Zachos, James C. Flower, Benjamin P. Tripati, Aradhna 2000-10-01T07:00:00Z application/pdf https://digitalcommons.usf.edu/msc_facpub/22 https://doi.org/10.1029/1999PA000443 https://digitalcommons.usf.edu/context/msc_facpub/article/1021/viewcontent/Paul_et_al_2000_Paleoceanography.pdf unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/22 doi:10.1029/1999PA000443 https://digitalcommons.usf.edu/context/msc_facpub/article/1021/viewcontent/Paul_et_al_2000_Paleoceanography.pdf default Marine Science Faculty Publications Life Sciences Marine Biology article 2000 ftusouthflorida https://doi.org/10.1029/1999PA000443 2023-07-13T20:21:41Z To assess the influence of orbital-scale variations on late Oligocene to early Miocene climate and ocean chemistry, high-resolution (similar to 5 kyr) benthic foraminiferal carbon and oxygen isotope and percent coarse fraction time series were constructed for Ocean Drilling Program site 929 on Ceara Rise in the western equatorial Atlantic. These time series exhibit pervasive low- to high-frequency variability across a 5-Myr interval (20.5-25.4 Ma). The records also reveal several large-scale secular variations including two positive (similar to 1.6 parts per thousand) oxygen isotope excursions at 22.95 and 21.1 Ma, suggestive of large but brief glacial maxima (Mi-l and Mi-la events of Miller et al. [1991]), and a long-term cyclical increase in the carbon isotopic composition of seawater (shift of similar to 1.52 parts per thousand) that reaches a maximum coincident with peak delta(18)O values at 22.95 Ma. Lower-resolution (similar to 25 kyr) records constructed from benthic and planktonic foraminifera as well as bulk carbonate at a shallower site on Ceara Rise (site 926) for the period 21.7-24.9 Ma covary with site 929 delta(18)O values reflecting changes in Antarctic ice-volume. Likewise, covariance among carbon isotopic records of bulk sediment, benthic, and planktonic foraminifera suggest that the low-frequency cycles (similar to 400 kyr) and long-term increase in delta(13)C values represent changes in the mean carbon composition of seawater Sigma CO2. The time series presented here constitute the longest, most continuous, and highest-resolution records of pre-Pliocene climate and oceanography to date. The site 929 carbon and oxygen isotope power spectra show significant concentrations of variance at similar to 400, 100, and 41 kyr, demonstrating that orbitally induced oscillations have been a normal characteristic of the global climate system since at least the Oligocene, including periods of equable climate and times with no apparent Northern Component Water production. Article in Journal/Newspaper Antarc* Antarctic Planktonic foraminifera University of South Florida St. Petersburg: Digital USFSP Antarctic Paleoceanography 15 5 471 485 |
institution |
Open Polar |
collection |
University of South Florida St. Petersburg: Digital USFSP |
op_collection_id |
ftusouthflorida |
language |
unknown |
topic |
Life Sciences Marine Biology |
spellingShingle |
Life Sciences Marine Biology Paul, Hilary A. Zachos, James C. Flower, Benjamin P. Tripati, Aradhna Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary |
topic_facet |
Life Sciences Marine Biology |
description |
To assess the influence of orbital-scale variations on late Oligocene to early Miocene climate and ocean chemistry, high-resolution (similar to 5 kyr) benthic foraminiferal carbon and oxygen isotope and percent coarse fraction time series were constructed for Ocean Drilling Program site 929 on Ceara Rise in the western equatorial Atlantic. These time series exhibit pervasive low- to high-frequency variability across a 5-Myr interval (20.5-25.4 Ma). The records also reveal several large-scale secular variations including two positive (similar to 1.6 parts per thousand) oxygen isotope excursions at 22.95 and 21.1 Ma, suggestive of large but brief glacial maxima (Mi-l and Mi-la events of Miller et al. [1991]), and a long-term cyclical increase in the carbon isotopic composition of seawater (shift of similar to 1.52 parts per thousand) that reaches a maximum coincident with peak delta(18)O values at 22.95 Ma. Lower-resolution (similar to 25 kyr) records constructed from benthic and planktonic foraminifera as well as bulk carbonate at a shallower site on Ceara Rise (site 926) for the period 21.7-24.9 Ma covary with site 929 delta(18)O values reflecting changes in Antarctic ice-volume. Likewise, covariance among carbon isotopic records of bulk sediment, benthic, and planktonic foraminifera suggest that the low-frequency cycles (similar to 400 kyr) and long-term increase in delta(13)C values represent changes in the mean carbon composition of seawater Sigma CO2. The time series presented here constitute the longest, most continuous, and highest-resolution records of pre-Pliocene climate and oceanography to date. The site 929 carbon and oxygen isotope power spectra show significant concentrations of variance at similar to 400, 100, and 41 kyr, demonstrating that orbitally induced oscillations have been a normal characteristic of the global climate system since at least the Oligocene, including periods of equable climate and times with no apparent Northern Component Water production. |
format |
Article in Journal/Newspaper |
author |
Paul, Hilary A. Zachos, James C. Flower, Benjamin P. Tripati, Aradhna |
author_facet |
Paul, Hilary A. Zachos, James C. Flower, Benjamin P. Tripati, Aradhna |
author_sort |
Paul, Hilary A. |
title |
Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary |
title_short |
Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary |
title_full |
Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary |
title_fullStr |
Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary |
title_full_unstemmed |
Orbitally Induced Climate and Geochemical Variability Across the Oligocene/Miocene Boundary |
title_sort |
orbitally induced climate and geochemical variability across the oligocene/miocene boundary |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2000 |
url |
https://digitalcommons.usf.edu/msc_facpub/22 https://doi.org/10.1029/1999PA000443 https://digitalcommons.usf.edu/context/msc_facpub/article/1021/viewcontent/Paul_et_al_2000_Paleoceanography.pdf |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Planktonic foraminifera |
genre_facet |
Antarc* Antarctic Planktonic foraminifera |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/22 doi:10.1029/1999PA000443 https://digitalcommons.usf.edu/context/msc_facpub/article/1021/viewcontent/Paul_et_al_2000_Paleoceanography.pdf |
op_rights |
default |
op_doi |
https://doi.org/10.1029/1999PA000443 |
container_title |
Paleoceanography |
container_volume |
15 |
container_issue |
5 |
container_start_page |
471 |
op_container_end_page |
485 |
_version_ |
1772821168045162496 |