Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern.
Nd and Pb isotopes were measured on the fine fraction of one sediment core drilled off southern Greenland. This work aims to reconstruct the evolution of deep circulation patterns in the North Atlantic during the Holocene on the basis of sediment supply variations. For the last 12 kyr, three sources...
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American Geophysical Union
2004
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Online Access: | http://hdl.handle.net/2429/39103 |
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ftunivbritcolcir:oai:circle.library.ubc.ca:2429/39103 2023-05-15T16:00:38+02:00 Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern. Weis, Dominique University of British Columbia. Pacific Centre for Isotopic and Geochemical Research 2004 http://hdl.handle.net/2429/39103 eng eng American Geophysical Union Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ CC-BY-NC-ND Low-temperature Geochemistry Text Article 2004 ftunivbritcolcir 2019-10-15T18:07:06Z Nd and Pb isotopes were measured on the fine fraction of one sediment core drilled off southern Greenland. This work aims to reconstruct the evolution of deep circulation patterns in the North Atlantic during the Holocene on the basis of sediment supply variations. For the last 12 kyr, three sources have contributed to the sediment mixture: the North American Shield, the Pan-African and Variscan crusts, and the Mid-Atlantic Ridge. Clay isotope signatures indicate two mixtures of sediment sources. The first mixture (12.2–6.5 ka) is composed of material derived from the North American shield and from a “young” crustal source. From 6.5 ka onward the mixture is characterized by a young crustal component and by a volcanic component characteristic of the Mid-Atlantic Ridge. Since the significant decrease in proximal deglacial supplies, the evolution of the relative contributions of the sediment sources suggests major changes in the relative contributions of the deep water masses carried by the Western Boundary Undercurrent over the past 8.4 kyr. The progressive intensification of the Western Boundary Undercurrent was initially associated mainly with the transport of the Northeast Atlantic Deep Water mass until 6.5 ka and with the Denmark Strait Overflow Water thereafter. The establishment of the modern circulation at 3 ka suggests a reduced influence of the Denmark Strait Overflow Water, synchronous with the full appearance of the Labrador Seawater mass. Our isotopic data set emphasizes several changes in the relative contribution of the two major components of North Atlantic Deep Water throughout the Holocene. An edited version of this paper was published by AGU. Copyright 2004 American Geophysical Union. Science, Faculty of Earth and Ocean Sciences, Department of Reviewed Faculty Article in Journal/Newspaper Denmark Strait Greenland Labrador Sea North Atlantic Deep Water North Atlantic Northeast Atlantic University of British Columbia: cIRcle - UBC's Information Repository Greenland Mid-Atlantic Ridge |
institution |
Open Polar |
collection |
University of British Columbia: cIRcle - UBC's Information Repository |
op_collection_id |
ftunivbritcolcir |
language |
English |
topic |
Low-temperature Geochemistry |
spellingShingle |
Low-temperature Geochemistry Weis, Dominique Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern. |
topic_facet |
Low-temperature Geochemistry |
description |
Nd and Pb isotopes were measured on the fine fraction of one sediment core drilled off southern Greenland. This work aims to reconstruct the evolution of deep circulation patterns in the North Atlantic during the Holocene on the basis of sediment supply variations. For the last 12 kyr, three sources have contributed to the sediment mixture: the North American Shield, the Pan-African and Variscan crusts, and the Mid-Atlantic Ridge. Clay isotope signatures indicate two mixtures of sediment sources. The first mixture (12.2–6.5 ka) is composed of material derived from the North American shield and from a “young” crustal source. From 6.5 ka onward the mixture is characterized by a young crustal component and by a volcanic component characteristic of the Mid-Atlantic Ridge. Since the significant decrease in proximal deglacial supplies, the evolution of the relative contributions of the sediment sources suggests major changes in the relative contributions of the deep water masses carried by the Western Boundary Undercurrent over the past 8.4 kyr. The progressive intensification of the Western Boundary Undercurrent was initially associated mainly with the transport of the Northeast Atlantic Deep Water mass until 6.5 ka and with the Denmark Strait Overflow Water thereafter. The establishment of the modern circulation at 3 ka suggests a reduced influence of the Denmark Strait Overflow Water, synchronous with the full appearance of the Labrador Seawater mass. Our isotopic data set emphasizes several changes in the relative contribution of the two major components of North Atlantic Deep Water throughout the Holocene. An edited version of this paper was published by AGU. Copyright 2004 American Geophysical Union. Science, Faculty of Earth and Ocean Sciences, Department of Reviewed Faculty |
author2 |
University of British Columbia. Pacific Centre for Isotopic and Geochemical Research |
format |
Article in Journal/Newspaper |
author |
Weis, Dominique |
author_facet |
Weis, Dominique |
author_sort |
Weis, Dominique |
title |
Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern. |
title_short |
Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern. |
title_full |
Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern. |
title_fullStr |
Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern. |
title_full_unstemmed |
Nd and Pb isotope signatures of the clay-size fraction of Labrador Sea sediments during the Holocene: Implications for the inception of the modern deep circulation pattern. |
title_sort |
nd and pb isotope signatures of the clay-size fraction of labrador sea sediments during the holocene: implications for the inception of the modern deep circulation pattern. |
publisher |
American Geophysical Union |
publishDate |
2004 |
url |
http://hdl.handle.net/2429/39103 |
geographic |
Greenland Mid-Atlantic Ridge |
geographic_facet |
Greenland Mid-Atlantic Ridge |
genre |
Denmark Strait Greenland Labrador Sea North Atlantic Deep Water North Atlantic Northeast Atlantic |
genre_facet |
Denmark Strait Greenland Labrador Sea North Atlantic Deep Water North Atlantic Northeast Atlantic |
op_rights |
Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_rightsnorm |
CC-BY-NC-ND |
_version_ |
1766396641524318208 |