A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin
International audience We produced a composite depth scale and chronology for Site U1385 on the SW Iberian Margin. Using log(Ca/Ti) measured by core scanning XRF at 1-cm resolution in all holes, a composite section was constructed to 166.5 meter composite depth (mcd) that corrects for stretching and...
Published in: | Global and Planetary Change |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Online Access: | https://hal.archives-ouvertes.fr/hal-01692015 https://doi.org/10.1016/j.gloplacha.2015.07.002 |
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ftccsdartic:oai:HAL:hal-01692015v1 2023-05-15T16:30:19+02:00 A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin Hodell, D. Lourens, Lucas j. Crowhurst, S. Konijnendijk, T. Tjallingii, Rik Jiménez-espejo, F. Skinner, R. Tzedakis, P. C. Shackleton site project, Members LOFI, Johanna University of Cambridge Utrecht University Utrecht Department of Marine Geology, Texel JAMSTEC University College London Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS) 2015-10-01 https://hal.archives-ouvertes.fr/hal-01692015 https://doi.org/10.1016/j.gloplacha.2015.07.002 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gloplacha.2015.07.002 hal-01692015 https://hal.archives-ouvertes.fr/hal-01692015 doi:10.1016/j.gloplacha.2015.07.002 ISSN: 0921-8181 Global and Planetary Change https://hal.archives-ouvertes.fr/hal-01692015 Global and Planetary Change, Elsevier, 2015, 133, pp.49-64. ⟨10.1016/j.gloplacha.2015.07.002⟩ [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/article Journal articles 2015 ftccsdartic https://doi.org/10.1016/j.gloplacha.2015.07.002 2021-10-31T08:02:19Z International audience We produced a composite depth scale and chronology for Site U1385 on the SW Iberian Margin. Using log(Ca/Ti) measured by core scanning XRF at 1-cm resolution in all holes, a composite section was constructed to 166.5 meter composite depth (mcd) that corrects for stretching and squeezing in each core. Oxygen isotopes of benthic foraminifera were correlated to a stacked δ18O reference signal (LR04) to produce an oxygen isotope stratigraphy and age model.Variations in sediment color contain very strong precession signals at Site U1385, and the amplitude modulation of these cycles provides a powerful tool for developing an orbitally-tuned age model. We tuned the U1385 record by correlating peaks in L* to the local summer insolation maxima at 37°N. The benthic δ18O record of Site U1385, when placed on the tuned age model, generally agrees with other time scales within their respective chronologic uncertainties.The age model is transferred to down-core data to produce a continuous time series of log(Ca/Ti) that reflect relative changes of biogenic carbonate and detrital sediment. Biogenic carbonate increases during interglacial and interstadial climate states and decreases during glacial and stadial periods. Much of the variance in the log(Ca/Ti) is explained by a linear combination of orbital frequencies (precession, tilt and eccentricity), whereas the residual signal reflects suborbital climate variability. The strong correlation between suborbital log(Ca/Ti) variability and Greenland temperature over the last glacial cycle at Site U1385 suggests that this signal can be used as a proxy for millennial-scale climate variability over the past 1.5 Ma.Millennial climate variability, as expressed by log(Ca/Ti) at Site U1385, was a persistent feature of glacial climates over the past 1.5 Ma, including glacial periods of the early Pleistocene (‘41-kyr world’) when boundary conditions differed significantly from those of the late Pleistocene (‘100-kyr world’). Suborbital variability was suppressed ... Article in Journal/Newspaper Greenland Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Greenland Shackleton Global and Planetary Change 133 49 64 |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
[SDE.MCG]Environmental Sciences/Global Changes Hodell, D. Lourens, Lucas j. Crowhurst, S. Konijnendijk, T. Tjallingii, Rik Jiménez-espejo, F. Skinner, R. Tzedakis, P. C. Shackleton site project, Members LOFI, Johanna A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin |
topic_facet |
[SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience We produced a composite depth scale and chronology for Site U1385 on the SW Iberian Margin. Using log(Ca/Ti) measured by core scanning XRF at 1-cm resolution in all holes, a composite section was constructed to 166.5 meter composite depth (mcd) that corrects for stretching and squeezing in each core. Oxygen isotopes of benthic foraminifera were correlated to a stacked δ18O reference signal (LR04) to produce an oxygen isotope stratigraphy and age model.Variations in sediment color contain very strong precession signals at Site U1385, and the amplitude modulation of these cycles provides a powerful tool for developing an orbitally-tuned age model. We tuned the U1385 record by correlating peaks in L* to the local summer insolation maxima at 37°N. The benthic δ18O record of Site U1385, when placed on the tuned age model, generally agrees with other time scales within their respective chronologic uncertainties.The age model is transferred to down-core data to produce a continuous time series of log(Ca/Ti) that reflect relative changes of biogenic carbonate and detrital sediment. Biogenic carbonate increases during interglacial and interstadial climate states and decreases during glacial and stadial periods. Much of the variance in the log(Ca/Ti) is explained by a linear combination of orbital frequencies (precession, tilt and eccentricity), whereas the residual signal reflects suborbital climate variability. The strong correlation between suborbital log(Ca/Ti) variability and Greenland temperature over the last glacial cycle at Site U1385 suggests that this signal can be used as a proxy for millennial-scale climate variability over the past 1.5 Ma.Millennial climate variability, as expressed by log(Ca/Ti) at Site U1385, was a persistent feature of glacial climates over the past 1.5 Ma, including glacial periods of the early Pleistocene (‘41-kyr world’) when boundary conditions differed significantly from those of the late Pleistocene (‘100-kyr world’). Suborbital variability was suppressed ... |
author2 |
University of Cambridge Utrecht University Utrecht Department of Marine Geology, Texel JAMSTEC University College London Géosciences Montpellier Institut national des sciences de l'Univers (INSU - CNRS)-Université de Montpellier (UM)-Université des Antilles (UA)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Hodell, D. Lourens, Lucas j. Crowhurst, S. Konijnendijk, T. Tjallingii, Rik Jiménez-espejo, F. Skinner, R. Tzedakis, P. C. Shackleton site project, Members LOFI, Johanna |
author_facet |
Hodell, D. Lourens, Lucas j. Crowhurst, S. Konijnendijk, T. Tjallingii, Rik Jiménez-espejo, F. Skinner, R. Tzedakis, P. C. Shackleton site project, Members LOFI, Johanna |
author_sort |
Hodell, D. |
title |
A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin |
title_short |
A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin |
title_full |
A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin |
title_fullStr |
A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin |
title_full_unstemmed |
A reference time scale for Site U1385 (Shackleton Site) on the SW Iberian Margin |
title_sort |
reference time scale for site u1385 (shackleton site) on the sw iberian margin |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.archives-ouvertes.fr/hal-01692015 https://doi.org/10.1016/j.gloplacha.2015.07.002 |
geographic |
Greenland Shackleton |
geographic_facet |
Greenland Shackleton |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
ISSN: 0921-8181 Global and Planetary Change https://hal.archives-ouvertes.fr/hal-01692015 Global and Planetary Change, Elsevier, 2015, 133, pp.49-64. ⟨10.1016/j.gloplacha.2015.07.002⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.gloplacha.2015.07.002 hal-01692015 https://hal.archives-ouvertes.fr/hal-01692015 doi:10.1016/j.gloplacha.2015.07.002 |
op_doi |
https://doi.org/10.1016/j.gloplacha.2015.07.002 |
container_title |
Global and Planetary Change |
container_volume |
133 |
container_start_page |
49 |
op_container_end_page |
64 |
_version_ |
1766020044349767680 |