Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon
Oceanic zircon trace element and Hf-isotope geochemistry offers a means to assess the magmatic evolution of a dying spreading ridge and provides an independent evaluation of the reliability of oceanic zircon as an indicator of mantle melting conditions. The Macquarie Island ophiolite in the Southern...
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ftmacquarieunicr:oai:https://researchers.mq.edu.au:publications/6184451c-fd15-47b7-afd6-ad8ace1ecad8 2024-06-23T07:54:31+00:00 Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon Portner, Ryan A. Daczko, Nathan R. Murphy, Melissa J. Pearson, Norman J. 2011-10 https://researchers.mq.edu.au/en/publications/6184451c-fd15-47b7-afd6-ad8ace1ecad8 https://doi.org/10.1016/j.lithos.2011.07.017 http://www.scopus.com/inward/record.url?scp=80054049045&partnerID=8YFLogxK eng eng info:eu-repo/semantics/closedAccess Portner , R A , Daczko , N R , Murphy , M J & Pearson , N J 2011 , ' Enriching mantle melts within a dying mid-ocean spreading ridge : Insights from Hf-isotope and trace element patterns in detrital oceanic zircon ' , Lithos , vol. 126 , no. 3-4 , pp. 355-368 . https://doi.org/10.1016/j.lithos.2011.07.017 article 2011 ftmacquarieunicr https://doi.org/10.1016/j.lithos.2011.07.017 2024-06-12T23:47:20Z Oceanic zircon trace element and Hf-isotope geochemistry offers a means to assess the magmatic evolution of a dying spreading ridge and provides an independent evaluation of the reliability of oceanic zircon as an indicator of mantle melting conditions. The Macquarie Island ophiolite in the Southern Ocean provides a unique testing ground for this approach due to its formation within a mid-ocean ridge that gradually changed into a transform plate boundary. Detrital zircon recovered from the island records this change through a progressive enrichment in incompatible trace elements. Oligocene age (33-27. Ma) paleo-detrital zircon in ophiolitic sandstones and breccias interbedded with pillow basalt have trace element compositions akin to a MORB crustal source, whereas Late Miocene age (8.5. Ma) modern-detrital zircon collected from gabbroic colluvium on the island have highly enriched compositions unlike typical oceanic zircon. This compositional disparity between age populations is not complimented by analytically equivalent εHf data that primarily ranges from 14 to 13 for sandstone and modern-detrital populations. A wider compositional range for the sandstone population reflects a multiple pluton source provenance and is augmented by a single cobble clast with εHf equivalent to the maximum observed composition in the sandstone (~. 17). Similar sandstone and colluvium Hf-isotope signatures indicate inheritance from a similar mantle reservoir that was enriched from the depleted MORB mantle average. The continuity in Hf-isotope signature relative to trace element enrichment in Macquarie Island zircon populations, suggests the latter formed by reduced partial melting linked to spreading-segment shortening and transform lengthening along the dying spreading ridge. Article in Journal/Newspaper Macquarie Island Southern Ocean Macquarie University Research Portal Southern Ocean Lithos 126 3-4 355 368 |
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Open Polar |
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Macquarie University Research Portal |
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ftmacquarieunicr |
language |
English |
description |
Oceanic zircon trace element and Hf-isotope geochemistry offers a means to assess the magmatic evolution of a dying spreading ridge and provides an independent evaluation of the reliability of oceanic zircon as an indicator of mantle melting conditions. The Macquarie Island ophiolite in the Southern Ocean provides a unique testing ground for this approach due to its formation within a mid-ocean ridge that gradually changed into a transform plate boundary. Detrital zircon recovered from the island records this change through a progressive enrichment in incompatible trace elements. Oligocene age (33-27. Ma) paleo-detrital zircon in ophiolitic sandstones and breccias interbedded with pillow basalt have trace element compositions akin to a MORB crustal source, whereas Late Miocene age (8.5. Ma) modern-detrital zircon collected from gabbroic colluvium on the island have highly enriched compositions unlike typical oceanic zircon. This compositional disparity between age populations is not complimented by analytically equivalent εHf data that primarily ranges from 14 to 13 for sandstone and modern-detrital populations. A wider compositional range for the sandstone population reflects a multiple pluton source provenance and is augmented by a single cobble clast with εHf equivalent to the maximum observed composition in the sandstone (~. 17). Similar sandstone and colluvium Hf-isotope signatures indicate inheritance from a similar mantle reservoir that was enriched from the depleted MORB mantle average. The continuity in Hf-isotope signature relative to trace element enrichment in Macquarie Island zircon populations, suggests the latter formed by reduced partial melting linked to spreading-segment shortening and transform lengthening along the dying spreading ridge. |
format |
Article in Journal/Newspaper |
author |
Portner, Ryan A. Daczko, Nathan R. Murphy, Melissa J. Pearson, Norman J. |
spellingShingle |
Portner, Ryan A. Daczko, Nathan R. Murphy, Melissa J. Pearson, Norman J. Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon |
author_facet |
Portner, Ryan A. Daczko, Nathan R. Murphy, Melissa J. Pearson, Norman J. |
author_sort |
Portner, Ryan A. |
title |
Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon |
title_short |
Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon |
title_full |
Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon |
title_fullStr |
Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon |
title_full_unstemmed |
Enriching mantle melts within a dying mid-ocean spreading ridge:Insights from Hf-isotope and trace element patterns in detrital oceanic zircon |
title_sort |
enriching mantle melts within a dying mid-ocean spreading ridge:insights from hf-isotope and trace element patterns in detrital oceanic zircon |
publishDate |
2011 |
url |
https://researchers.mq.edu.au/en/publications/6184451c-fd15-47b7-afd6-ad8ace1ecad8 https://doi.org/10.1016/j.lithos.2011.07.017 http://www.scopus.com/inward/record.url?scp=80054049045&partnerID=8YFLogxK |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Macquarie Island Southern Ocean |
genre_facet |
Macquarie Island Southern Ocean |
op_source |
Portner , R A , Daczko , N R , Murphy , M J & Pearson , N J 2011 , ' Enriching mantle melts within a dying mid-ocean spreading ridge : Insights from Hf-isotope and trace element patterns in detrital oceanic zircon ' , Lithos , vol. 126 , no. 3-4 , pp. 355-368 . https://doi.org/10.1016/j.lithos.2011.07.017 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/j.lithos.2011.07.017 |
container_title |
Lithos |
container_volume |
126 |
container_issue |
3-4 |
container_start_page |
355 |
op_container_end_page |
368 |
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1802646703547875328 |