Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle
Sr, Nd and Pb isotope data for basalts from spreading axes and off-axis volcanoes near the Pacific–Antarctic risecrest, from Vacquier transform to just south of Udintsev transform, reveal an isotopically heterogeneous upper mantle. The isotopic composition of the mantle is represented by three end-m...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.331.8707 2023-05-15T13:50:14+02:00 Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle Paterno R. Castillo A James H. Natl Yaoling Niu C Peter F. Lonsdale A The Pennsylvania State University CiteSeerX Archives 1997 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.331.8707 http://www.dur.ac.uk/yaoling.niu/MyReprints-pdf/1998CastilloEtAl.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.331.8707 http://www.dur.ac.uk/yaoling.niu/MyReprints-pdf/1998CastilloEtAl.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.dur.ac.uk/yaoling.niu/MyReprints-pdf/1998CastilloEtAl.pdf text 1997 ftciteseerx 2016-09-11T00:03:02Z Sr, Nd and Pb isotope data for basalts from spreading axes and off-axis volcanoes near the Pacific–Antarctic risecrest, from Vacquier transform to just south of Udintsev transform, reveal an isotopically heterogeneous upper mantle. The isotopic composition of the mantle is represented by three end-members: Ž. 1 the ‘depleted ’ source of the bulk of Pacific normal-type mid-ocean ridge basalts Ž N-MORB.; Ž 2. an ‘enriched ’ source that produces basalts of the Hollister Ridge; and Ž. 3 a source, restricted to two adjacent sample locales, similar to that of Indian MORB. The distribution of these isotopic heterogeneities along the Pacific–Antarctic risecrest suggests two alternative hypotheses on the nature and dynamics of the south Pacific upper mantle. The whole area could be a single N-MORB mantle domain that shows a weak but continuous increase in 143 Ndr 144Nd from northeast to southwest across more than 2000 km of sea floor. The gradient is unrelated to the Louisville hotspot because Louisville basalts have low 143 Ndr 144Nd and the hotspot’s influence along the ridge is spatially limited and near the high 143 Ndr 144Nd southwestern end of the gradient. The gradient appears consistent with a southwestward flow of the Pacific N-MORB-type mantle that has been proposed mainly on the basis of ridge morphology. That the N-MORB mantle domain is continuous across Heezen suggests that large-scale magmatic segmentation is not related to the largest structural offsets of the Pacific ridges. Alternatively, the higher 87 Srr 86Sr, DNd and D8r4 of samples Text Antarc* Antarctic Unknown Antarctic Indian Pacific |
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Open Polar |
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ftciteseerx |
language |
English |
description |
Sr, Nd and Pb isotope data for basalts from spreading axes and off-axis volcanoes near the Pacific–Antarctic risecrest, from Vacquier transform to just south of Udintsev transform, reveal an isotopically heterogeneous upper mantle. The isotopic composition of the mantle is represented by three end-members: Ž. 1 the ‘depleted ’ source of the bulk of Pacific normal-type mid-ocean ridge basalts Ž N-MORB.; Ž 2. an ‘enriched ’ source that produces basalts of the Hollister Ridge; and Ž. 3 a source, restricted to two adjacent sample locales, similar to that of Indian MORB. The distribution of these isotopic heterogeneities along the Pacific–Antarctic risecrest suggests two alternative hypotheses on the nature and dynamics of the south Pacific upper mantle. The whole area could be a single N-MORB mantle domain that shows a weak but continuous increase in 143 Ndr 144Nd from northeast to southwest across more than 2000 km of sea floor. The gradient is unrelated to the Louisville hotspot because Louisville basalts have low 143 Ndr 144Nd and the hotspot’s influence along the ridge is spatially limited and near the high 143 Ndr 144Nd southwestern end of the gradient. The gradient appears consistent with a southwestward flow of the Pacific N-MORB-type mantle that has been proposed mainly on the basis of ridge morphology. That the N-MORB mantle domain is continuous across Heezen suggests that large-scale magmatic segmentation is not related to the largest structural offsets of the Pacific ridges. Alternatively, the higher 87 Srr 86Sr, DNd and D8r4 of samples |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Paterno R. Castillo A James H. Natl Yaoling Niu C Peter F. Lonsdale A |
spellingShingle |
Paterno R. Castillo A James H. Natl Yaoling Niu C Peter F. Lonsdale A Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle |
author_facet |
Paterno R. Castillo A James H. Natl Yaoling Niu C Peter F. Lonsdale A |
author_sort |
Paterno R. Castillo A |
title |
Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle |
title_short |
Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle |
title_full |
Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle |
title_fullStr |
Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle |
title_full_unstemmed |
Sr, Nd and Pb isotopic variation along the Pacific–Antarctic risecrest, 53–578S: Implications for the composition and dynamics of the South Pacific upper mantle |
title_sort |
sr, nd and pb isotopic variation along the pacific–antarctic risecrest, 53–578s: implications for the composition and dynamics of the south pacific upper mantle |
publishDate |
1997 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.331.8707 http://www.dur.ac.uk/yaoling.niu/MyReprints-pdf/1998CastilloEtAl.pdf |
geographic |
Antarctic Indian Pacific |
geographic_facet |
Antarctic Indian Pacific |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
http://www.dur.ac.uk/yaoling.niu/MyReprints-pdf/1998CastilloEtAl.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.331.8707 http://www.dur.ac.uk/yaoling.niu/MyReprints-pdf/1998CastilloEtAl.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766253262092107776 |