Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts
Hydrogenetic ferromanganese crusts incorporate elements from ambient seawater during their growth on seamounts. By analysing Nd, Pb and Be isotope profiles within crusts it is possible to reconstruct seawater tracer histories. Depth profiles of Be-10/Be-9 ratios in three Pacific ferromanganese crust...
Published in: | Earth and Planetary Science Letters |
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1997
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ftqueensland:oai:eprints.qut.edu.au:126204 2024-05-12T08:02:58+00:00 Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts Ling, H. F. Burton, K. W. Onions, R. K. Kamber, B. S. von Blanckenburg, F. Gibb, A. J. Hein, J. R. 1997 https://eprints.qut.edu.au/126204/ unknown Elsevier BV doi:10.1016/s0012-821x(96)00224-5 Ling, H. F., Burton, K. W., Onions, R. K., Kamber, B. S., von Blanckenburg, F., Gibb, A. J., & Hein, J. R. (1997) Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts. Earth and Planetary Science Letters, 146(1-2), pp. 1-12. https://eprints.qut.edu.au/126204/ Science & Engineering Faculty; Australian Research Centre for Aerospace Automation Consult author(s) regarding copyright matters This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the document is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recognise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to qut.copyright@qut.edu.au Earth and Planetary Science Letters Central Pacific neodymium lead residence time rare-earth elements north pacific neodymium isotopes atlantic-ocean drake passage east pacific sm-nd strontium deposits sr Geochemistry & Geophysics Contribution to Journal 1997 ftqueensland https://doi.org/10.1016/s0012-821x(96)00224-5 2024-04-17T14:24:35Z Hydrogenetic ferromanganese crusts incorporate elements from ambient seawater during their growth on seamounts. By analysing Nd, Pb and Be isotope profiles within crusts it is possible to reconstruct seawater tracer histories. Depth profiles of Be-10/Be-9 ratios in three Pacific ferromanganese crusts have been used to obtain growth rates which are between 1.4 and 3.8 mm/Ma. Nd and Pb isotopes provide intact records of isotopic variations in Pacific seawater over the last 20 Ma or more. There were only small changes in Pb isotope composition in the last 20 Ma. This indicates a constant Pb composition for the erosional sources and suggests further that erosional Nd inputs may have been uniform too. epsilon(Nd) values vary considerably with time and most probably reflect changes in ocean circulation. The epsilon(Nd) values of the crusts not only vary as a function of age but also as a function of water depth. From 25 to 0 Ma, crust VA13/2 from 4.8 km water depth has a similar pattern of epsilon(Nd) variation to the two shallower crusts from 1.8 and 2.3 km, but about 1.0 to 1.5 units more negative. This suggests that epsilon(Nd) stratification in Pacific seawater, as demonstrated for the present day, has been maintained for at least 20 Ma. Each crust shows a decrease in epsilon(Nd) from 3-5 Ma to the present, which is interpreted in terms of an increase in the NADW component present in the Pacific. From 10 to 3-5 Ma ago the crusts show an increase in epsilon(Nd). This suggests a decreasing role for a deep water source with epsilon(Nd) less than circumpacific sources. In this regard the Panamanian gateway restriction from similar to 10 Ma with final closure at 3-5 Ma may have played an important role in reducing access of Atlantic-derived Nd to the Pacific. Article in Journal/Newspaper Drake Passage NADW Queensland University of Technology: QUT ePrints Drake Passage Pacific Earth and Planetary Science Letters 146 1-2 1 12 |
institution |
Open Polar |
collection |
Queensland University of Technology: QUT ePrints |
op_collection_id |
ftqueensland |
language |
unknown |
topic |
Central Pacific neodymium lead residence time rare-earth elements north pacific neodymium isotopes atlantic-ocean drake passage east pacific sm-nd strontium deposits sr Geochemistry & Geophysics |
spellingShingle |
Central Pacific neodymium lead residence time rare-earth elements north pacific neodymium isotopes atlantic-ocean drake passage east pacific sm-nd strontium deposits sr Geochemistry & Geophysics Ling, H. F. Burton, K. W. Onions, R. K. Kamber, B. S. von Blanckenburg, F. Gibb, A. J. Hein, J. R. Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts |
topic_facet |
Central Pacific neodymium lead residence time rare-earth elements north pacific neodymium isotopes atlantic-ocean drake passage east pacific sm-nd strontium deposits sr Geochemistry & Geophysics |
description |
Hydrogenetic ferromanganese crusts incorporate elements from ambient seawater during their growth on seamounts. By analysing Nd, Pb and Be isotope profiles within crusts it is possible to reconstruct seawater tracer histories. Depth profiles of Be-10/Be-9 ratios in three Pacific ferromanganese crusts have been used to obtain growth rates which are between 1.4 and 3.8 mm/Ma. Nd and Pb isotopes provide intact records of isotopic variations in Pacific seawater over the last 20 Ma or more. There were only small changes in Pb isotope composition in the last 20 Ma. This indicates a constant Pb composition for the erosional sources and suggests further that erosional Nd inputs may have been uniform too. epsilon(Nd) values vary considerably with time and most probably reflect changes in ocean circulation. The epsilon(Nd) values of the crusts not only vary as a function of age but also as a function of water depth. From 25 to 0 Ma, crust VA13/2 from 4.8 km water depth has a similar pattern of epsilon(Nd) variation to the two shallower crusts from 1.8 and 2.3 km, but about 1.0 to 1.5 units more negative. This suggests that epsilon(Nd) stratification in Pacific seawater, as demonstrated for the present day, has been maintained for at least 20 Ma. Each crust shows a decrease in epsilon(Nd) from 3-5 Ma to the present, which is interpreted in terms of an increase in the NADW component present in the Pacific. From 10 to 3-5 Ma ago the crusts show an increase in epsilon(Nd). This suggests a decreasing role for a deep water source with epsilon(Nd) less than circumpacific sources. In this regard the Panamanian gateway restriction from similar to 10 Ma with final closure at 3-5 Ma may have played an important role in reducing access of Atlantic-derived Nd to the Pacific. |
format |
Article in Journal/Newspaper |
author |
Ling, H. F. Burton, K. W. Onions, R. K. Kamber, B. S. von Blanckenburg, F. Gibb, A. J. Hein, J. R. |
author_facet |
Ling, H. F. Burton, K. W. Onions, R. K. Kamber, B. S. von Blanckenburg, F. Gibb, A. J. Hein, J. R. |
author_sort |
Ling, H. F. |
title |
Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts |
title_short |
Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts |
title_full |
Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts |
title_fullStr |
Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts |
title_full_unstemmed |
Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts |
title_sort |
evolution of nd and pb isotopes in central pacific seawater from ferromanganese crusts |
publisher |
Elsevier BV |
publishDate |
1997 |
url |
https://eprints.qut.edu.au/126204/ |
geographic |
Drake Passage Pacific |
geographic_facet |
Drake Passage Pacific |
genre |
Drake Passage NADW |
genre_facet |
Drake Passage NADW |
op_source |
Earth and Planetary Science Letters |
op_relation |
doi:10.1016/s0012-821x(96)00224-5 Ling, H. F., Burton, K. W., Onions, R. K., Kamber, B. S., von Blanckenburg, F., Gibb, A. J., & Hein, J. R. (1997) Evolution of Nd and Pb isotopes in Central Pacific seawater from ferromanganese crusts. Earth and Planetary Science Letters, 146(1-2), pp. 1-12. https://eprints.qut.edu.au/126204/ Science & Engineering Faculty; Australian Research Centre for Aerospace Automation |
op_rights |
Consult author(s) regarding copyright matters This work is covered by copyright. Unless the document is being made available under a Creative Commons Licence, you must assume that re-use is limited to personal use and that permission from the copyright owner must be obtained for all other uses. If the document is available under a Creative Commons License (or other specified license) then refer to the Licence for details of permitted re-use. It is a condition of access that users recognise and abide by the legal requirements associated with these rights. If you believe that this work infringes copyright please provide details by email to qut.copyright@qut.edu.au |
op_doi |
https://doi.org/10.1016/s0012-821x(96)00224-5 |
container_title |
Earth and Planetary Science Letters |
container_volume |
146 |
container_issue |
1-2 |
container_start_page |
1 |
op_container_end_page |
12 |
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1798845106211520512 |