The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands
This paper presents field, geochemical and isotopic (Sr, Nd, Pb) results on basalts from the Antipodes, Campbell and Chatham Islands, New Zealand. New 40Ar/39Ar age determinations along with previous K-Ar dates reveal three major episodes of volcanic activity on Chatham Island (85-82, 41-35, ∼5 Ma)....
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fthighwire:oai:open-archive.highwire.org:petrology:egl024v1 2023-05-15T13:51:53+02:00 The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands PANTER, K. S. BLUSZTAJN, J. HART, S. R. KYLE, P. R. ESSER, R. McINTOSH, W. C. 2006-05-04 07:20:57.0 text/html http://petrology.oxfordjournals.org/cgi/content/short/egl024v1 https://doi.org/10.1093/petrology/egl024 en eng Oxford University Press http://petrology.oxfordjournals.org/cgi/content/short/egl024v1 http://dx.doi.org/10.1093/petrology/egl024 Copyright (C) 2006, Oxford University Press Article TEXT 2006 fthighwire https://doi.org/10.1093/petrology/egl024 2007-06-24T20:22:56Z This paper presents field, geochemical and isotopic (Sr, Nd, Pb) results on basalts from the Antipodes, Campbell and Chatham Islands, New Zealand. New 40Ar/39Ar age determinations along with previous K-Ar dates reveal three major episodes of volcanic activity on Chatham Island (85-82, 41-35, ∼5 Ma). Chatham and Antipodes samples comprise basanite, alkali and transitional basalts that have HIMU-like isotopic (206Pb/204Pb > 20·3-20·8, 87Sr/86Sr <0·7033, 143Nd/144Nd >0·5128) and trace element affinities (Ce/Pb 28-36, Nb/U 34-66, Ba/Nb 4-7). The geochemistry of transitional to Q -normative samples from Campbell Island is explained by interaction with continental crust. The volcanism is part of a long-lived (∼100 Myr), low-volume, diffuse alkaline magmatic province that includes deposits on the North and South Islands of New Zealand as well as portions of West Antarctica and SE Australia. All of these continental areas were juxtaposed on the eastern margin of Gondwanaland at >83 Ma. A ubiquitous feature of mafic alkaline rocks from this region is their depletion in K and Pb relative to other highly incompatible elements when normalized to primitive mantle values. The inversion of trace element data indicates enriched mantle sources that contain variable proportions of hydrous minerals. We propose that the mantle sources represent continental lithosphere that host amphibole/phlogopite-rich veins formed by plume- and/or subduction-related metasomatism between 500 and 100 Ma. The strong HIMU signature (206Pb/204Pb >20·5) is considered to be an in-grown feature generated by partial dehydration and loss of hydrophile elements (Pb, Rb, K) relative to more magmaphile elements (Th, U, Sr) during short-term storage at the base of the lithosphere. Text Antarc* Antarctica West Antarctica HighWire Press (Stanford University) West Antarctica Pacific New Zealand Campbell Island ENVELOPE(169.500,169.500,-52.500,-52.500) Journal of Petrology 47 9 1673 1704 |
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English |
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Article PANTER, K. S. BLUSZTAJN, J. HART, S. R. KYLE, P. R. ESSER, R. McINTOSH, W. C. The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands |
topic_facet |
Article |
description |
This paper presents field, geochemical and isotopic (Sr, Nd, Pb) results on basalts from the Antipodes, Campbell and Chatham Islands, New Zealand. New 40Ar/39Ar age determinations along with previous K-Ar dates reveal three major episodes of volcanic activity on Chatham Island (85-82, 41-35, ∼5 Ma). Chatham and Antipodes samples comprise basanite, alkali and transitional basalts that have HIMU-like isotopic (206Pb/204Pb > 20·3-20·8, 87Sr/86Sr <0·7033, 143Nd/144Nd >0·5128) and trace element affinities (Ce/Pb 28-36, Nb/U 34-66, Ba/Nb 4-7). The geochemistry of transitional to Q -normative samples from Campbell Island is explained by interaction with continental crust. The volcanism is part of a long-lived (∼100 Myr), low-volume, diffuse alkaline magmatic province that includes deposits on the North and South Islands of New Zealand as well as portions of West Antarctica and SE Australia. All of these continental areas were juxtaposed on the eastern margin of Gondwanaland at >83 Ma. A ubiquitous feature of mafic alkaline rocks from this region is their depletion in K and Pb relative to other highly incompatible elements when normalized to primitive mantle values. The inversion of trace element data indicates enriched mantle sources that contain variable proportions of hydrous minerals. We propose that the mantle sources represent continental lithosphere that host amphibole/phlogopite-rich veins formed by plume- and/or subduction-related metasomatism between 500 and 100 Ma. The strong HIMU signature (206Pb/204Pb >20·5) is considered to be an in-grown feature generated by partial dehydration and loss of hydrophile elements (Pb, Rb, K) relative to more magmaphile elements (Th, U, Sr) during short-term storage at the base of the lithosphere. |
format |
Text |
author |
PANTER, K. S. BLUSZTAJN, J. HART, S. R. KYLE, P. R. ESSER, R. McINTOSH, W. C. |
author_facet |
PANTER, K. S. BLUSZTAJN, J. HART, S. R. KYLE, P. R. ESSER, R. McINTOSH, W. C. |
author_sort |
PANTER, K. S. |
title |
The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands |
title_short |
The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands |
title_full |
The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands |
title_fullStr |
The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands |
title_full_unstemmed |
The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands |
title_sort |
origin of himu in the sw pacific: evidence from intraplate volcanism in southern new zealand and subantarctic islands |
publisher |
Oxford University Press |
publishDate |
2006 |
url |
http://petrology.oxfordjournals.org/cgi/content/short/egl024v1 https://doi.org/10.1093/petrology/egl024 |
long_lat |
ENVELOPE(169.500,169.500,-52.500,-52.500) |
geographic |
West Antarctica Pacific New Zealand Campbell Island |
geographic_facet |
West Antarctica Pacific New Zealand Campbell Island |
genre |
Antarc* Antarctica West Antarctica |
genre_facet |
Antarc* Antarctica West Antarctica |
op_relation |
http://petrology.oxfordjournals.org/cgi/content/short/egl024v1 http://dx.doi.org/10.1093/petrology/egl024 |
op_rights |
Copyright (C) 2006, Oxford University Press |
op_doi |
https://doi.org/10.1093/petrology/egl024 |
container_title |
Journal of Petrology |
container_volume |
47 |
container_issue |
9 |
container_start_page |
1673 |
op_container_end_page |
1704 |
_version_ |
1766255933332127744 |