Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper]
A complete, well-preserved record of the Cenomanian/Turonian (C/T) Oceanic Anoxic Event 2 (OAE-2) was recovered from Demerara Rise in the southern North Atlantic Ocean (ODP site 1260). Across this interval, we determined changes in the stable carbon isotopic composition of sulfur-bound phytane (δ13C...
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ftunivfrankfurt:oai:publikationen.ub.uni-frankfurt.de:23492 2023-05-15T17:28:35+02:00 Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper] Bentum, Elisabeth C. van Reichart, Gert-Jan Forster, Astrid Sinninghe Damsté, Jacobus S. 2011-06-30 application/pdf http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/23492 https://nbn-resolving.org/urn:nbn:de:hebis:30:3-234924 https://doi.org/10.5194/bgd-8-6191-2011 http://publikationen.ub.uni-frankfurt.de/files/23492/bgd-8-6191-2011-print.pdf eng eng http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/23492 urn:nbn:de:hebis:30:3-234924 https://nbn-resolving.org/urn:nbn:de:hebis:30:3-234924 https://doi.org/10.5194/bgd-8-6191-2011 http://publikationen.ub.uni-frankfurt.de/files/23492/bgd-8-6191-2011-print.pdf http://creativecommons.org/licenses/by/3.0/de/deed.de info:eu-repo/semantics/openAccess CC-BY ddc:550 article doc-type:article 2011 ftunivfrankfurt https://doi.org/10.5194/bgd-8-6191-2011 2022-09-11T22:59:02Z A complete, well-preserved record of the Cenomanian/Turonian (C/T) Oceanic Anoxic Event 2 (OAE-2) was recovered from Demerara Rise in the southern North Atlantic Ocean (ODP site 1260). Across this interval, we determined changes in the stable carbon isotopic composition of sulfur-bound phytane (δ13Cphytane, a biomarker for photosynthetic algae. The δ13Cphytane record shows a positive excursion at the onset of the OAE-2 interval, with an unusually large amplitude (~7 ‰) compared to existing C/T proto-North Atlantic δ13Cphytane records (3–6 ‰). Overall, the amplitude of the excursion of δ13Cphytane decreases with latitude. Using reconstructed sea surface temperature (SST) gradients for the proto-North Atlantic, we investigated environmental factors influencing the latitudinal δ13Cphytane gradient. The observed gradient is best explained by high productivity at DSDP Site 367 and Tarfaya basin before OAE-2, which changed in overall high productivity throughout the proto-North Atlantic during OAE-2. During OAE-2, productivity at site 1260 and 603B was thus more comparable to the mid-latitude sites. Using these constraints as well as the SST and δ13Cphytane-records from Site 1260, we subsequently reconstructed pCO2 levels across the OAE-2 interval. Accordingly, pCO2 decreased from ca. 1750 to 900 ppm during OAE-2, consistent with enhanced organic matter burial resulting in lowering pCO2. Whereas the onset of OAE-2 coincided with increased pCO2, in line with a volcanic trigger for this event, the observed cooling within OAE-2 probably resulted from CO2 sequestration in black shales outcompeting CO2 input into the atmosphere. Together these results show that the ice-free Cretaceous world was sensitive to changes in pCO2 related to perturbations of the global carbon cycle. Article in Journal/Newspaper North Atlantic Publication Server of Goethe University Frankfurt am Main |
institution |
Open Polar |
collection |
Publication Server of Goethe University Frankfurt am Main |
op_collection_id |
ftunivfrankfurt |
language |
English |
topic |
ddc:550 |
spellingShingle |
ddc:550 Bentum, Elisabeth C. van Reichart, Gert-Jan Forster, Astrid Sinninghe Damsté, Jacobus S. Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper] |
topic_facet |
ddc:550 |
description |
A complete, well-preserved record of the Cenomanian/Turonian (C/T) Oceanic Anoxic Event 2 (OAE-2) was recovered from Demerara Rise in the southern North Atlantic Ocean (ODP site 1260). Across this interval, we determined changes in the stable carbon isotopic composition of sulfur-bound phytane (δ13Cphytane, a biomarker for photosynthetic algae. The δ13Cphytane record shows a positive excursion at the onset of the OAE-2 interval, with an unusually large amplitude (~7 ‰) compared to existing C/T proto-North Atlantic δ13Cphytane records (3–6 ‰). Overall, the amplitude of the excursion of δ13Cphytane decreases with latitude. Using reconstructed sea surface temperature (SST) gradients for the proto-North Atlantic, we investigated environmental factors influencing the latitudinal δ13Cphytane gradient. The observed gradient is best explained by high productivity at DSDP Site 367 and Tarfaya basin before OAE-2, which changed in overall high productivity throughout the proto-North Atlantic during OAE-2. During OAE-2, productivity at site 1260 and 603B was thus more comparable to the mid-latitude sites. Using these constraints as well as the SST and δ13Cphytane-records from Site 1260, we subsequently reconstructed pCO2 levels across the OAE-2 interval. Accordingly, pCO2 decreased from ca. 1750 to 900 ppm during OAE-2, consistent with enhanced organic matter burial resulting in lowering pCO2. Whereas the onset of OAE-2 coincided with increased pCO2, in line with a volcanic trigger for this event, the observed cooling within OAE-2 probably resulted from CO2 sequestration in black shales outcompeting CO2 input into the atmosphere. Together these results show that the ice-free Cretaceous world was sensitive to changes in pCO2 related to perturbations of the global carbon cycle. |
format |
Article in Journal/Newspaper |
author |
Bentum, Elisabeth C. van Reichart, Gert-Jan Forster, Astrid Sinninghe Damsté, Jacobus S. |
author_facet |
Bentum, Elisabeth C. van Reichart, Gert-Jan Forster, Astrid Sinninghe Damsté, Jacobus S. |
author_sort |
Bentum, Elisabeth C. van |
title |
Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper] |
title_short |
Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper] |
title_full |
Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper] |
title_fullStr |
Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper] |
title_full_unstemmed |
Latitudinal differences in the amplitude of the OAE-2 carbon isotopic excursion: pCO2 and paleoproductivity [Discussion paper] |
title_sort |
latitudinal differences in the amplitude of the oae-2 carbon isotopic excursion: pco2 and paleoproductivity [discussion paper] |
publishDate |
2011 |
url |
http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/23492 https://nbn-resolving.org/urn:nbn:de:hebis:30:3-234924 https://doi.org/10.5194/bgd-8-6191-2011 http://publikationen.ub.uni-frankfurt.de/files/23492/bgd-8-6191-2011-print.pdf |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/23492 urn:nbn:de:hebis:30:3-234924 https://nbn-resolving.org/urn:nbn:de:hebis:30:3-234924 https://doi.org/10.5194/bgd-8-6191-2011 http://publikationen.ub.uni-frankfurt.de/files/23492/bgd-8-6191-2011-print.pdf |
op_rights |
http://creativecommons.org/licenses/by/3.0/de/deed.de info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/bgd-8-6191-2011 |
_version_ |
1766121331388055552 |