The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 10 (2009): Q03006, doi:10.1029/2008GC002324. We report 87Sr...
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Language: | English |
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American Geophysical Union
2009
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Online Access: | https://hdl.handle.net/1912/3292 |
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/3292 2023-05-15T15:33:57+02:00 The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions Jackson, Matthew G. Hart, Stanley R. Shimizu, Nobumichi Blusztajn, Jerzy S. 2009-03-11 application/pdf https://hdl.handle.net/1912/3292 en_US eng American Geophysical Union https://doi.org/10.1029/2008GC002324 Geochemistry Geophysics Geosystems 10 (2009): Q03006 https://hdl.handle.net/1912/3292 doi:10.1029/2008GC002324 Geochemistry Geophysics Geosystems 10 (2009): Q03006 doi:10.1029/2008GC002324 Clinopyroxene Melt inclusion Mantle geochemistry Sr-87/Sr-86 Nd-143/Nd-144 Trace elements Article 2009 ftwhoas https://doi.org/10.1029/2008GC002324 2022-05-28T22:57:53Z Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 10 (2009): Q03006, doi:10.1029/2008GC002324. We report 87Sr/86Sr and 143Nd/144Nd data on clinopyroxenes recovered from 10 ocean island lavas from three different hot spots (Samoa, Society, and Cook-Austral island chains). The clinopyroxenes recovered from eight of the 10 lavas analyzed in this study exhibit 87Sr/86Sr disequilibrium with respect to the host lava. The 87Sr/86Sr ratios in clinopyroxene separates are 95–3146 ppm (0.0095–0.31%) different from their respective host whole rocks. Clinopyroxenes in three lavas have 143Nd/144Nd ratios that are 70–160 ppm (0.007–0.016%) different from the host lavas. The 87Sr/86Sr and 143Nd/144Nd disequilibrium in one lava (the oldest lava considered in this study, Mangaia sample MGA-B-47) can be attributed to posteruptive radiogenic ingrowth, but the isotope disequilibrium in the other, younger lavas cannot be explained by this mechanism. In five of the lava samples, two populations of clinopyroxene were isolated (black and green, separated by color). In four out of five of these samples, the 87Sr/86Sr ratios of the two clinopyroxene populations are isotopically different from each other. In addition to 87Sr/86Sr disequilibrium, the two clinopyroxene populations in one of the lavas (Tahaa sample TAA-B-26) have 143Nd/144Nd ratios that are ∼100 ppm different from each other. Given the resilience of clinopyroxene to seawater alteration and the likelihood that the Sr and Nd isotope composition of fresh clinopyroxene separates provides a faithful record of primary magmatic compositions, the clinopyroxene-clinopyroxene isotope disequilibrium in these four lavas provides strong evidence that a mechanism other than seawater alteration has generated the observed isotopic disequilibrium. This study confirms the isotopic diversity in ocean ... Article in Journal/Newspaper Austral Island Ocean Island Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Austral Austral Island ENVELOPE(110.650,110.650,-66.500,-66.500) Geochemistry, Geophysics, Geosystems 10 3 n/a n/a |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Clinopyroxene Melt inclusion Mantle geochemistry Sr-87/Sr-86 Nd-143/Nd-144 Trace elements |
spellingShingle |
Clinopyroxene Melt inclusion Mantle geochemistry Sr-87/Sr-86 Nd-143/Nd-144 Trace elements Jackson, Matthew G. Hart, Stanley R. Shimizu, Nobumichi Blusztajn, Jerzy S. The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions |
topic_facet |
Clinopyroxene Melt inclusion Mantle geochemistry Sr-87/Sr-86 Nd-143/Nd-144 Trace elements |
description |
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 10 (2009): Q03006, doi:10.1029/2008GC002324. We report 87Sr/86Sr and 143Nd/144Nd data on clinopyroxenes recovered from 10 ocean island lavas from three different hot spots (Samoa, Society, and Cook-Austral island chains). The clinopyroxenes recovered from eight of the 10 lavas analyzed in this study exhibit 87Sr/86Sr disequilibrium with respect to the host lava. The 87Sr/86Sr ratios in clinopyroxene separates are 95–3146 ppm (0.0095–0.31%) different from their respective host whole rocks. Clinopyroxenes in three lavas have 143Nd/144Nd ratios that are 70–160 ppm (0.007–0.016%) different from the host lavas. The 87Sr/86Sr and 143Nd/144Nd disequilibrium in one lava (the oldest lava considered in this study, Mangaia sample MGA-B-47) can be attributed to posteruptive radiogenic ingrowth, but the isotope disequilibrium in the other, younger lavas cannot be explained by this mechanism. In five of the lava samples, two populations of clinopyroxene were isolated (black and green, separated by color). In four out of five of these samples, the 87Sr/86Sr ratios of the two clinopyroxene populations are isotopically different from each other. In addition to 87Sr/86Sr disequilibrium, the two clinopyroxene populations in one of the lavas (Tahaa sample TAA-B-26) have 143Nd/144Nd ratios that are ∼100 ppm different from each other. Given the resilience of clinopyroxene to seawater alteration and the likelihood that the Sr and Nd isotope composition of fresh clinopyroxene separates provides a faithful record of primary magmatic compositions, the clinopyroxene-clinopyroxene isotope disequilibrium in these four lavas provides strong evidence that a mechanism other than seawater alteration has generated the observed isotopic disequilibrium. This study confirms the isotopic diversity in ocean ... |
format |
Article in Journal/Newspaper |
author |
Jackson, Matthew G. Hart, Stanley R. Shimizu, Nobumichi Blusztajn, Jerzy S. |
author_facet |
Jackson, Matthew G. Hart, Stanley R. Shimizu, Nobumichi Blusztajn, Jerzy S. |
author_sort |
Jackson, Matthew G. |
title |
The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions |
title_short |
The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions |
title_full |
The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions |
title_fullStr |
The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions |
title_full_unstemmed |
The Sr-87/Sr-86 and Nd-143/Nd-144 disequilibrium between Polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions |
title_sort |
sr-87/sr-86 and nd-143/nd-144 disequilibrium between polynesian hot spot lavas and the clinopyroxenes they host : evidence complementing isotopic disequilibrium in melt inclusions |
publisher |
American Geophysical Union |
publishDate |
2009 |
url |
https://hdl.handle.net/1912/3292 |
long_lat |
ENVELOPE(110.650,110.650,-66.500,-66.500) |
geographic |
Austral Austral Island |
geographic_facet |
Austral Austral Island |
genre |
Austral Island Ocean Island |
genre_facet |
Austral Island Ocean Island |
op_source |
Geochemistry Geophysics Geosystems 10 (2009): Q03006 doi:10.1029/2008GC002324 |
op_relation |
https://doi.org/10.1029/2008GC002324 Geochemistry Geophysics Geosystems 10 (2009): Q03006 https://hdl.handle.net/1912/3292 doi:10.1029/2008GC002324 |
op_doi |
https://doi.org/10.1029/2008GC002324 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
10 |
container_issue |
3 |
container_start_page |
n/a |
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n/a |
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1766364530698354688 |