Sr/Ca ratios of coccoliths from the Paleocene-Eocene Thermal Maximum

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Auteurs principaux: Stoll, Heather M, Shimizu, Nobumichi, Archer, David E, Ziveri, Patrizia
Format: Dataset Open Access
Langue:en
Publié: PANGAEA 2007
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author Stoll, Heather M
Shimizu, Nobumichi
Archer, David E
Ziveri, Patrizia
author_facet Stoll, Heather M
Shimizu, Nobumichi
Archer, David E
Ziveri, Patrizia
collection Datos científicos de ciencias marinas y ambientales
contents During the Paleocene-Eocene Thermal Maximum (PETM), rapid release of isotopically light C to the ocean-atmosphere system elevated the greenhouse effect and warmed temperatures by 5-7 °C for 105 yr. The response of the planktic ecosystems and productivity to the dramatic climate changes of the PETM may represent a significant feedback to the carbon cycle changes, but has been difficult to document. We examine Sr/Ca ratios in calcareous nannofossils in sediments spanning the PETM in three open ocean sites as a new approach to examine productivity and ecological shifts in calcifying plankton. The large heterogeneity in Sr/Ca among different nannofossil genera indicates that nannofossil Sr/Ca reflects primary productivity-driven geochemical signals and not diagenetic overprinting. Elevated Sr/Ca ratios in several genera and constant ratios in other genera suggest increased overall productivity in the Atlantic sector of the Southern Ocean during the PETM. Dominant nannofossil genera in tropical Atlantic and Pacific sites show Sr/Ca variations during the PETM which are comparable to background variability prior to the PETM. Despite acidification of the ocean there was not a productivity crisis among calcifying phytoplankton. We use the Pandora ocean box model to explore possible mechanisms for PETM productivity change. If independent proxy evidence for more stratified conditions in the Southern Ocean during the PETM is robust, then maintenance of stable or increased productivity there likely reflects increased nutrient inventories of the ocean. Increased nutrient inventories could have resulted from climatically enhanced weathering and would have important implications for burial rates of organic carbon and stabilization of climate and the carbon cycle.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_715051
institution PANGAEA
language en
publishDate 2007
publisher PANGAEA
record_format pangaea
spellingShingle Sr/Ca ratios of coccoliths from the Paleocene-Eocene Thermal Maximum
Stoll, Heather M
Shimizu, Nobumichi
Archer, David E
Ziveri, Patrizia
113-690B; 198-1209C; 207-1258A; DRILL; Drilling/drill rig; Joides Resolution; Leg113; Leg198; Leg207; North Atlantic Ocean; North Pacific Ocean; Ocean Drilling Program; ODP; South Atlantic Ocean
During the Paleocene-Eocene Thermal Maximum (PETM), rapid release of isotopically light C to the ocean-atmosphere system elevated the greenhouse effect and warmed temperatures by 5-7 °C for 105 yr. The response of the planktic ecosystems and productivity to the dramatic climate changes of the PETM may represent a significant feedback to the carbon cycle changes, but has been difficult to document. We examine Sr/Ca ratios in calcareous nannofossils in sediments spanning the PETM in three open ocean sites as a new approach to examine productivity and ecological shifts in calcifying plankton. The large heterogeneity in Sr/Ca among different nannofossil genera indicates that nannofossil Sr/Ca reflects primary productivity-driven geochemical signals and not diagenetic overprinting. Elevated Sr/Ca ratios in several genera and constant ratios in other genera suggest increased overall productivity in the Atlantic sector of the Southern Ocean during the PETM. Dominant nannofossil genera in tropical Atlantic and Pacific sites show Sr/Ca variations during the PETM which are comparable to background variability prior to the PETM. Despite acidification of the ocean there was not a productivity crisis among calcifying phytoplankton. We use the Pandora ocean box model to explore possible mechanisms for PETM productivity change. If independent proxy evidence for more stratified conditions in the Southern Ocean during the PETM is robust, then maintenance of stable or increased productivity there likely reflects increased nutrient inventories of the ocean. Increased nutrient inventories could have resulted from climatically enhanced weathering and would have important implications for burial rates of organic carbon and stabilization of climate and the carbon cycle.
title Sr/Ca ratios of coccoliths from the Paleocene-Eocene Thermal Maximum
topic 113-690B; 198-1209C; 207-1258A; DRILL; Drilling/drill rig; Joides Resolution; Leg113; Leg198; Leg207; North Atlantic Ocean; North Pacific Ocean; Ocean Drilling Program; ODP; South Atlantic Ocean
url https://doi.org/10.1594/PANGAEA.715051