Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans
Two ferromanganese crusts from the Indian Ocean and one from the Atlantic Ocean have been analysed for 10Be/:9Be, 143Nd/144Nd and 208,207,206Pb 204Pb ratios as a function of depth beneath their growth surfaces. 10Be/9Be ratios provide growth rate estimates for these crusts between 1.55 and 2.82 mm M...
Published in: | Earth and Planetary Science Letters |
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1998
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_237672 2023-05-15T17:32:33+02:00 Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans O'Nions, R. Frank, M. von Blanckenburg, F. Ling, H. 0 Pre-GFZ, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum 1998 https://gfzpublic.gfz-potsdam.de/pubman/item/item_237672 unknown info:eu-repo/semantics/altIdentifier/doi/10.1016/S0012-821X(97)00207-0 https://gfzpublic.gfz-potsdam.de/pubman/item/item_237672 Earth and Planetary Science Letters 550 - Earth sciences info:eu-repo/semantics/article 1998 ftgfzpotsdam https://doi.org/10.1016/S0012-821X(97)00207-0 2022-09-14T05:54:31Z Two ferromanganese crusts from the Indian Ocean and one from the Atlantic Ocean have been analysed for 10Be/:9Be, 143Nd/144Nd and 208,207,206Pb 204Pb ratios as a function of depth beneath their growth surfaces. 10Be/9Be ratios provide growth rate estimates for these crusts between 1.55 and 2.82 mm Ma-1 and further suggest that 87Sr/86Sr in crusts do not in any case examined so far provide reliable estimates for growth rates. A crust ALV-539 from 35°N in the western N. Atlantic has εNd and Pb-isotope variations indistinguishable from crust BM-1969.05 from 39°N in the N. Atlantic [K.W. Burton, H.-F. Ling, R.K. O’Nions, Closure of the central American isthmus and its impact on North Atlantic deepwater circulation, Nature (London) 386 (1997) 382–385] when (hoch:10)Be/(hoch:10)Be ratios are used to estimate growth rates. Both crusts provide evidence for a marked change in deepwater composition in the western N. Atlantic with a reduction in εNd and an increase in (hoch:206)Pb/(hoch: 204)Pb from ∼ 8 Ma ago towards the present day. The two crusts from the Indian Ocean show comparatively small variations in εNd between -8.0 and -7.0 over the last 20 Ma and do not show the large shift in εNd seen in the Atlantic crusts. Comparison of εNd in the crusts analysed here with those published previously [H.-F. Ling, K.W. Burton, R.K. O’Nions, B.S. Kamber, F. von Blanckenburg, A.J. Gibb, J.R. Hein, Evolution of Nd and Pb isotopes in central Pacific seawater from ferromanganese crusts, Earth Planet. Sci. Lett. 146 (1997) 1–12; K.W. Burton, H-F. Ling, R.K. O’Nions, Closure of the central American isthmus and its impact on North Atlantic deepwater circulation, Nature (London) 386 (1997) 382–385] shows that provinciality in the present-day εNd structure of the Pacific, Atlantic and Indian Oceans has been maintained over ∼ 20 Ma or more despite the palaeogeographic changes that have occurred within this period. These include the closure of the Panama gateway and the uplift of the Himalayas. Superimposed on this broad inter-ocean ... Article in Journal/Newspaper North Atlantic GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) Pacific Indian Burton ENVELOPE(166.733,166.733,-72.550,-72.550) Earth and Planetary Science Letters 155 1-2 15 28 |
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Open Polar |
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GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
unknown |
topic |
550 - Earth sciences |
spellingShingle |
550 - Earth sciences O'Nions, R. Frank, M. von Blanckenburg, F. Ling, H. Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans |
topic_facet |
550 - Earth sciences |
description |
Two ferromanganese crusts from the Indian Ocean and one from the Atlantic Ocean have been analysed for 10Be/:9Be, 143Nd/144Nd and 208,207,206Pb 204Pb ratios as a function of depth beneath their growth surfaces. 10Be/9Be ratios provide growth rate estimates for these crusts between 1.55 and 2.82 mm Ma-1 and further suggest that 87Sr/86Sr in crusts do not in any case examined so far provide reliable estimates for growth rates. A crust ALV-539 from 35°N in the western N. Atlantic has εNd and Pb-isotope variations indistinguishable from crust BM-1969.05 from 39°N in the N. Atlantic [K.W. Burton, H.-F. Ling, R.K. O’Nions, Closure of the central American isthmus and its impact on North Atlantic deepwater circulation, Nature (London) 386 (1997) 382–385] when (hoch:10)Be/(hoch:10)Be ratios are used to estimate growth rates. Both crusts provide evidence for a marked change in deepwater composition in the western N. Atlantic with a reduction in εNd and an increase in (hoch:206)Pb/(hoch: 204)Pb from ∼ 8 Ma ago towards the present day. The two crusts from the Indian Ocean show comparatively small variations in εNd between -8.0 and -7.0 over the last 20 Ma and do not show the large shift in εNd seen in the Atlantic crusts. Comparison of εNd in the crusts analysed here with those published previously [H.-F. Ling, K.W. Burton, R.K. O’Nions, B.S. Kamber, F. von Blanckenburg, A.J. Gibb, J.R. Hein, Evolution of Nd and Pb isotopes in central Pacific seawater from ferromanganese crusts, Earth Planet. Sci. Lett. 146 (1997) 1–12; K.W. Burton, H-F. Ling, R.K. O’Nions, Closure of the central American isthmus and its impact on North Atlantic deepwater circulation, Nature (London) 386 (1997) 382–385] shows that provinciality in the present-day εNd structure of the Pacific, Atlantic and Indian Oceans has been maintained over ∼ 20 Ma or more despite the palaeogeographic changes that have occurred within this period. These include the closure of the Panama gateway and the uplift of the Himalayas. Superimposed on this broad inter-ocean ... |
author2 |
0 Pre-GFZ, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum |
format |
Article in Journal/Newspaper |
author |
O'Nions, R. Frank, M. von Blanckenburg, F. Ling, H. |
author_facet |
O'Nions, R. Frank, M. von Blanckenburg, F. Ling, H. |
author_sort |
O'Nions, R. |
title |
Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans |
title_short |
Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans |
title_full |
Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans |
title_fullStr |
Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans |
title_full_unstemmed |
Secular variation of Nd and Pb isotopes in ferromanganese crusts from the Atlantic, Indian and Pacific Oceans |
title_sort |
secular variation of nd and pb isotopes in ferromanganese crusts from the atlantic, indian and pacific oceans |
publishDate |
1998 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_237672 |
long_lat |
ENVELOPE(166.733,166.733,-72.550,-72.550) |
geographic |
Pacific Indian Burton |
geographic_facet |
Pacific Indian Burton |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Earth and Planetary Science Letters |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/S0012-821X(97)00207-0 https://gfzpublic.gfz-potsdam.de/pubman/item/item_237672 |
op_doi |
https://doi.org/10.1016/S0012-821X(97)00207-0 |
container_title |
Earth and Planetary Science Letters |
container_volume |
155 |
container_issue |
1-2 |
container_start_page |
15 |
op_container_end_page |
28 |
_version_ |
1766130736380772352 |