Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts
The Western Mediterranean Deep Water (WMDW), on its way out toward the Atlantic Ocean, has favored the formation of contourite drifts in the Alboran Sea (SW Mediterranean) since the opening of the Strait of Gibraltar. Resolving the nature of these deposits is crucial for reconstructing the WMDW vari...
Published in: | Marine Geology |
---|---|
Main Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2021
|
Subjects: | |
Online Access: | https://biblio.ugent.be/publication/8773388 http://hdl.handle.net/1854/LU-8773388 https://doi.org/10.1016/j.margeo.2021.106488 https://biblio.ugent.be/publication/8773388/file/8773389 |
id |
ftunivgent:oai:archive.ugent.be:8773388 |
---|---|
record_format |
openpolar |
spelling |
ftunivgent:oai:archive.ugent.be:8773388 2023-06-11T04:15:03+02:00 Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts Alonso, B. Juan, C. Ercilla, G. Cacho, I Lopez-Gonzalez, N. Rodriquez-Tovar, F. J. Dorador, J. Frances, G. Casas, D. Vandorpe, Thomas Vazquez, J. T. 2021 application/pdf https://biblio.ugent.be/publication/8773388 http://hdl.handle.net/1854/LU-8773388 https://doi.org/10.1016/j.margeo.2021.106488 https://biblio.ugent.be/publication/8773388/file/8773389 eng eng https://biblio.ugent.be/publication/8773388 http://hdl.handle.net/1854/LU-8773388 http://dx.doi.org/10.1016/j.margeo.2021.106488 https://biblio.ugent.be/publication/8773388/file/8773389 Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License (CC BY-NC-ND 4.0) info:eu-repo/semantics/openAccess MARINE GEOLOGY ISSN: 0025-3227 ISSN: 1872-6151 Earth and Environmental Sciences Contourites Sortable silt Western Mediterranean Deep Water Paleoceanography Alboran Sea CURRENT-CONTROLLED SEDIMENTATION NORTH-ATLANTIC GRAIN-SIZE DEEP-WATER CLIMATIC VARIABILITY MUDDY CONTOURITES IMAGE TREATMENT SOLAR-ACTIVITY journalArticle info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2021 ftunivgent https://doi.org/10.1016/j.margeo.2021.106488 2023-05-31T22:07:11Z The Western Mediterranean Deep Water (WMDW), on its way out toward the Atlantic Ocean, has favored the formation of contourite drifts in the Alboran Sea (SW Mediterranean) since the opening of the Strait of Gibraltar. Resolving the nature of these deposits is crucial for reconstructing the WMDW variability at a millennial scale, deciphering its bottom current paleo-velocity, and establishing paleoclimatic implications over the last 25 cal. kyr BP. Two sediment cores retrieved from elongated separated and plastered contourite drifts formed along its path are investigated by means of multi-sedimentological data (terrigenous grain-size, sortable silt, terrigenous and carbonate sediment fluxes, bioturbation and ichnofabric changes), geochemical data (Zr/Al and Si/(Si + Al) ratios), chronostratigraphic data (delta O-18, and C-14 data) as well as statistical analyses (grain-size end-member modelling and spectral analysis). Integration of these data confirms the contouritic nature of Alboran drift deposits. The high-resolution paleocurrent records of the WMDW inferred from the sortable silt of contourite sequences led us to define two regimes in terms of WMDW flow energy. Regime 1 (weak to moderate velocity) defined by paleo-velocities of similar to 4 to 23 cm s(-1) is dominant during the last 24 cal kyr BP. Regime 2 (strong velocity) is characterized by estimated paleo-velocities of about similar to 36 cm s(-1) during Heinrich Stadial 2. The spectral analysis of bottom current proxies (sortable silt and Zr/Al ratio) matches four cyclic climatic signals (1900 yr, 2300 yr, 4000 ye and 6100 yr), corroborating the occurrence of millennial-scale cyclicity. These cycles are related to atmospheric climate variability, in turn linked to variations in solar activity. Our results, when combined with published data from a neighboring NW Mediterranean contourite drift, provide for a better regional understanding of the WMDW millennial-scale dynamics. Article in Journal/Newspaper North Atlantic Ghent University Academic Bibliography Marine Geology 437 106488 |
institution |
Open Polar |
collection |
Ghent University Academic Bibliography |
op_collection_id |
ftunivgent |
language |
English |
topic |
Earth and Environmental Sciences Contourites Sortable silt Western Mediterranean Deep Water Paleoceanography Alboran Sea CURRENT-CONTROLLED SEDIMENTATION NORTH-ATLANTIC GRAIN-SIZE DEEP-WATER CLIMATIC VARIABILITY MUDDY CONTOURITES IMAGE TREATMENT SOLAR-ACTIVITY |
spellingShingle |
Earth and Environmental Sciences Contourites Sortable silt Western Mediterranean Deep Water Paleoceanography Alboran Sea CURRENT-CONTROLLED SEDIMENTATION NORTH-ATLANTIC GRAIN-SIZE DEEP-WATER CLIMATIC VARIABILITY MUDDY CONTOURITES IMAGE TREATMENT SOLAR-ACTIVITY Alonso, B. Juan, C. Ercilla, G. Cacho, I Lopez-Gonzalez, N. Rodriquez-Tovar, F. J. Dorador, J. Frances, G. Casas, D. Vandorpe, Thomas Vazquez, J. T. Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts |
topic_facet |
Earth and Environmental Sciences Contourites Sortable silt Western Mediterranean Deep Water Paleoceanography Alboran Sea CURRENT-CONTROLLED SEDIMENTATION NORTH-ATLANTIC GRAIN-SIZE DEEP-WATER CLIMATIC VARIABILITY MUDDY CONTOURITES IMAGE TREATMENT SOLAR-ACTIVITY |
description |
The Western Mediterranean Deep Water (WMDW), on its way out toward the Atlantic Ocean, has favored the formation of contourite drifts in the Alboran Sea (SW Mediterranean) since the opening of the Strait of Gibraltar. Resolving the nature of these deposits is crucial for reconstructing the WMDW variability at a millennial scale, deciphering its bottom current paleo-velocity, and establishing paleoclimatic implications over the last 25 cal. kyr BP. Two sediment cores retrieved from elongated separated and plastered contourite drifts formed along its path are investigated by means of multi-sedimentological data (terrigenous grain-size, sortable silt, terrigenous and carbonate sediment fluxes, bioturbation and ichnofabric changes), geochemical data (Zr/Al and Si/(Si + Al) ratios), chronostratigraphic data (delta O-18, and C-14 data) as well as statistical analyses (grain-size end-member modelling and spectral analysis). Integration of these data confirms the contouritic nature of Alboran drift deposits. The high-resolution paleocurrent records of the WMDW inferred from the sortable silt of contourite sequences led us to define two regimes in terms of WMDW flow energy. Regime 1 (weak to moderate velocity) defined by paleo-velocities of similar to 4 to 23 cm s(-1) is dominant during the last 24 cal kyr BP. Regime 2 (strong velocity) is characterized by estimated paleo-velocities of about similar to 36 cm s(-1) during Heinrich Stadial 2. The spectral analysis of bottom current proxies (sortable silt and Zr/Al ratio) matches four cyclic climatic signals (1900 yr, 2300 yr, 4000 ye and 6100 yr), corroborating the occurrence of millennial-scale cyclicity. These cycles are related to atmospheric climate variability, in turn linked to variations in solar activity. Our results, when combined with published data from a neighboring NW Mediterranean contourite drift, provide for a better regional understanding of the WMDW millennial-scale dynamics. |
format |
Article in Journal/Newspaper |
author |
Alonso, B. Juan, C. Ercilla, G. Cacho, I Lopez-Gonzalez, N. Rodriquez-Tovar, F. J. Dorador, J. Frances, G. Casas, D. Vandorpe, Thomas Vazquez, J. T. |
author_facet |
Alonso, B. Juan, C. Ercilla, G. Cacho, I Lopez-Gonzalez, N. Rodriquez-Tovar, F. J. Dorador, J. Frances, G. Casas, D. Vandorpe, Thomas Vazquez, J. T. |
author_sort |
Alonso, B. |
title |
Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts |
title_short |
Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts |
title_full |
Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts |
title_fullStr |
Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts |
title_full_unstemmed |
Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP : new insights from contourite drifts |
title_sort |
paleoceanographic and paleoclimatic variability in the western mediterranean during the last 25 cal. kyr bp : new insights from contourite drifts |
publishDate |
2021 |
url |
https://biblio.ugent.be/publication/8773388 http://hdl.handle.net/1854/LU-8773388 https://doi.org/10.1016/j.margeo.2021.106488 https://biblio.ugent.be/publication/8773388/file/8773389 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
MARINE GEOLOGY ISSN: 0025-3227 ISSN: 1872-6151 |
op_relation |
https://biblio.ugent.be/publication/8773388 http://hdl.handle.net/1854/LU-8773388 http://dx.doi.org/10.1016/j.margeo.2021.106488 https://biblio.ugent.be/publication/8773388/file/8773389 |
op_rights |
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License (CC BY-NC-ND 4.0) info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.margeo.2021.106488 |
container_title |
Marine Geology |
container_volume |
437 |
container_start_page |
106488 |
_version_ |
1768371573844082688 |