Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean
International audience Abstract Geochemical data suggest that ocean circulation patterns changed over a period of long-term cooling during the last 10 m.y. of the Cretaceous (late Campanian–Maastrichtian). Proposed changes include enhanced deep-water formation in the South Atlantic and/or Indian sec...
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ftunivnantes:oai:HAL:hal-03845432v1 2023-05-15T17:34:32+02:00 Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean Haynes, Shannon Macleod, Kenneth Ladant, Jean-Baptiste Guchte, Andrew Vande Rostami, Masoud Poulsen, Christopher Martin, Ellen Department of Earth and Environmental Sciences Ann Arbor University of Michigan Ann Arbor University of Michigan System-University of Michigan System 2020-02-27 https://hal.archives-ouvertes.fr/hal-03845432 https://doi.org/10.1130/G47197.1 en eng HAL CCSD Geological Society of America info:eu-repo/semantics/altIdentifier/doi/10.1130/G47197.1 hal-03845432 https://hal.archives-ouvertes.fr/hal-03845432 doi:10.1130/G47197.1 ISSN: 0091-7613 EISSN: 0091-7613 Geology https://hal.archives-ouvertes.fr/hal-03845432 Geology, Geological Society of America, 2020, 48 (5), pp.509-513. ⟨10.1130/G47197.1⟩ [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology info:eu-repo/semantics/article Journal articles 2020 ftunivnantes https://doi.org/10.1130/G47197.1 2022-11-16T00:02:26Z International audience Abstract Geochemical data suggest that ocean circulation patterns changed over a period of long-term cooling during the last 10 m.y. of the Cretaceous (late Campanian–Maastrichtian). Proposed changes include enhanced deep-water formation in the South Atlantic and/or Indian sectors of the Southern Ocean, initiation or enhanced deep-water formation in the North Atlantic, and alternating regions of deep convection in the North and South Pacific. Existing geochemical data do not allow simple confirmation or rejection of any of these scenarios. To test Pacific circulation during the Maastrichtian, we measured neodymium isotopic (εNd) values from four Pacific Deep Sea Drilling Project and Ocean Drilling Program sites and compare results both to Earth system model simulations using Maastrichtian paleogeography and to previous studies. Pacific εNd results consistently show a small negative εNd excursion during a well-documented, ∼1–3 m.y. early Maastrichtian cooling pulse (EMCP) but no other consistent trends across the late Campanian–late Maastrichtian interval (∼10 m.y.). Model results show that different CO2 forcings lead to changes in rates, but not patterns, of circulation. These combined results support the existence of a sustained source region for intermediate and deep waters in the southwestern Pacific throughout the late Campanian–Maastrichtian and indicate that changes in εNd values during the EMCP reflect an increased rate of overturning in the Pacific rather than changes in the source area of Pacific bottom waters. Article in Journal/Newspaper North Atlantic Southern Ocean Université de Nantes: HAL-UNIV-NANTES Indian Pacific Southern Ocean Geology 48 5 509 513 |
institution |
Open Polar |
collection |
Université de Nantes: HAL-UNIV-NANTES |
op_collection_id |
ftunivnantes |
language |
English |
topic |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
spellingShingle |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology Haynes, Shannon Macleod, Kenneth Ladant, Jean-Baptiste Guchte, Andrew Vande Rostami, Masoud Poulsen, Christopher Martin, Ellen Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean |
topic_facet |
[SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology |
description |
International audience Abstract Geochemical data suggest that ocean circulation patterns changed over a period of long-term cooling during the last 10 m.y. of the Cretaceous (late Campanian–Maastrichtian). Proposed changes include enhanced deep-water formation in the South Atlantic and/or Indian sectors of the Southern Ocean, initiation or enhanced deep-water formation in the North Atlantic, and alternating regions of deep convection in the North and South Pacific. Existing geochemical data do not allow simple confirmation or rejection of any of these scenarios. To test Pacific circulation during the Maastrichtian, we measured neodymium isotopic (εNd) values from four Pacific Deep Sea Drilling Project and Ocean Drilling Program sites and compare results both to Earth system model simulations using Maastrichtian paleogeography and to previous studies. Pacific εNd results consistently show a small negative εNd excursion during a well-documented, ∼1–3 m.y. early Maastrichtian cooling pulse (EMCP) but no other consistent trends across the late Campanian–late Maastrichtian interval (∼10 m.y.). Model results show that different CO2 forcings lead to changes in rates, but not patterns, of circulation. These combined results support the existence of a sustained source region for intermediate and deep waters in the southwestern Pacific throughout the late Campanian–Maastrichtian and indicate that changes in εNd values during the EMCP reflect an increased rate of overturning in the Pacific rather than changes in the source area of Pacific bottom waters. |
author2 |
Department of Earth and Environmental Sciences Ann Arbor University of Michigan Ann Arbor University of Michigan System-University of Michigan System |
format |
Article in Journal/Newspaper |
author |
Haynes, Shannon Macleod, Kenneth Ladant, Jean-Baptiste Guchte, Andrew Vande Rostami, Masoud Poulsen, Christopher Martin, Ellen |
author_facet |
Haynes, Shannon Macleod, Kenneth Ladant, Jean-Baptiste Guchte, Andrew Vande Rostami, Masoud Poulsen, Christopher Martin, Ellen |
author_sort |
Haynes, Shannon |
title |
Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean |
title_short |
Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean |
title_full |
Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean |
title_fullStr |
Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean |
title_full_unstemmed |
Constraining sources and relative flow rates of bottom waters in the Late Cretaceous Pacific Ocean |
title_sort |
constraining sources and relative flow rates of bottom waters in the late cretaceous pacific ocean |
publisher |
HAL CCSD |
publishDate |
2020 |
url |
https://hal.archives-ouvertes.fr/hal-03845432 https://doi.org/10.1130/G47197.1 |
geographic |
Indian Pacific Southern Ocean |
geographic_facet |
Indian Pacific Southern Ocean |
genre |
North Atlantic Southern Ocean |
genre_facet |
North Atlantic Southern Ocean |
op_source |
ISSN: 0091-7613 EISSN: 0091-7613 Geology https://hal.archives-ouvertes.fr/hal-03845432 Geology, Geological Society of America, 2020, 48 (5), pp.509-513. ⟨10.1130/G47197.1⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1130/G47197.1 hal-03845432 https://hal.archives-ouvertes.fr/hal-03845432 doi:10.1130/G47197.1 |
op_doi |
https://doi.org/10.1130/G47197.1 |
container_title |
Geology |
container_volume |
48 |
container_issue |
5 |
container_start_page |
509 |
op_container_end_page |
513 |
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1766133399046586368 |