Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization
Nanospheres of lead (Pb) have recently been identified in zircon (ZrSiO(4)) with the potential to compromise the veracity of U-Pb age determinations. The key assumption that the determined age is robust against the effects of Pb mobility, as long as Pb is not lost from the zircon during subsequent g...
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ftpubmed:oai:pubmedcentral.nih.gov:6757063 2023-05-15T13:47:02+02:00 Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization Lyon, Ian C. Kusiak, Monika A. Wirth, Richard Whitehouse, Martin J. Dunkley, Daniel J. Wilde, Simon A. Schaumlöffel, Dirk Malherbe, Julien Moore, Katie L. 2019-09-23 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6757063/ http://www.ncbi.nlm.nih.gov/pubmed/31548570 https://doi.org/10.1038/s41598-019-49882-8 en eng Nature Publishing Group UK http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6757063/ http://www.ncbi.nlm.nih.gov/pubmed/31548570 http://dx.doi.org/10.1038/s41598-019-49882-8 © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. CC-BY Article Text 2019 ftpubmed https://doi.org/10.1038/s41598-019-49882-8 2019-10-06T00:33:43Z Nanospheres of lead (Pb) have recently been identified in zircon (ZrSiO(4)) with the potential to compromise the veracity of U-Pb age determinations. The key assumption that the determined age is robust against the effects of Pb mobility, as long as Pb is not lost from the zircon during subsequent geological events, is now in question. To determine the effect of nanosphere formation on age determination, and whether analysis of nanospheres can yield additional information about the timing of both zircon growth and nanosphere formation, zircons from the Napier Complex in Enderby Land, East Antarctica, were investigated by high-spatial resolution NanoSIMS (Secondary Ion Mass Spectrometry) mapping. Conventional SIMS analyses with >µm resolution potentially mixes Pb from multiple nanospheres with the zircon host, yielding variable average values and therefore unreliable ages. NanoSIMS analyses were obtained of (207)Pb/(206)Pb in nanospheres a few nanometres in diameter that were resolved from (207)Pb/(206)Pb measurements in the zircon host. We demonstrate that analysis for (207)Pb/(206)Pb in multiple individual Pb nanospheres, along with separate analysis of (207)Pb/(206)Pb in the zircon host, can not only accurately yield the age of zircon crystallization, but also the time of nanosphere formation resulting from Pb mobilization during metamorphism. Model ages for both events can be derived that are correlated due to the limited range of possible solutions that can be satisfied by the measured (207)Pb/(206)Pb ratios of nanospheres and zircon host. For the Napier Complex zircons, this yields a model age of ca 3110 Ma for zircon formation and a late Archean model age of 2610 Ma for the metamorphism that produced the nanospheres. The Nanosphere Model Age (NMA) method constrains both the crystallization age and age of the metamorphism to ~±135 Ma, a significant improvement on errors derived from counting statistics. Text Antarc* Antarctica East Antarctica Enderby Land PubMed Central (PMC) East Antarctica Napier ENVELOPE(-58.440,-58.440,-62.167,-62.167) Scientific Reports 9 1 |
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Article Lyon, Ian C. Kusiak, Monika A. Wirth, Richard Whitehouse, Martin J. Dunkley, Daniel J. Wilde, Simon A. Schaumlöffel, Dirk Malherbe, Julien Moore, Katie L. Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization |
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description |
Nanospheres of lead (Pb) have recently been identified in zircon (ZrSiO(4)) with the potential to compromise the veracity of U-Pb age determinations. The key assumption that the determined age is robust against the effects of Pb mobility, as long as Pb is not lost from the zircon during subsequent geological events, is now in question. To determine the effect of nanosphere formation on age determination, and whether analysis of nanospheres can yield additional information about the timing of both zircon growth and nanosphere formation, zircons from the Napier Complex in Enderby Land, East Antarctica, were investigated by high-spatial resolution NanoSIMS (Secondary Ion Mass Spectrometry) mapping. Conventional SIMS analyses with >µm resolution potentially mixes Pb from multiple nanospheres with the zircon host, yielding variable average values and therefore unreliable ages. NanoSIMS analyses were obtained of (207)Pb/(206)Pb in nanospheres a few nanometres in diameter that were resolved from (207)Pb/(206)Pb measurements in the zircon host. We demonstrate that analysis for (207)Pb/(206)Pb in multiple individual Pb nanospheres, along with separate analysis of (207)Pb/(206)Pb in the zircon host, can not only accurately yield the age of zircon crystallization, but also the time of nanosphere formation resulting from Pb mobilization during metamorphism. Model ages for both events can be derived that are correlated due to the limited range of possible solutions that can be satisfied by the measured (207)Pb/(206)Pb ratios of nanospheres and zircon host. For the Napier Complex zircons, this yields a model age of ca 3110 Ma for zircon formation and a late Archean model age of 2610 Ma for the metamorphism that produced the nanospheres. The Nanosphere Model Age (NMA) method constrains both the crystallization age and age of the metamorphism to ~±135 Ma, a significant improvement on errors derived from counting statistics. |
format |
Text |
author |
Lyon, Ian C. Kusiak, Monika A. Wirth, Richard Whitehouse, Martin J. Dunkley, Daniel J. Wilde, Simon A. Schaumlöffel, Dirk Malherbe, Julien Moore, Katie L. |
author_facet |
Lyon, Ian C. Kusiak, Monika A. Wirth, Richard Whitehouse, Martin J. Dunkley, Daniel J. Wilde, Simon A. Schaumlöffel, Dirk Malherbe, Julien Moore, Katie L. |
author_sort |
Lyon, Ian C. |
title |
Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization |
title_short |
Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization |
title_full |
Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization |
title_fullStr |
Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization |
title_full_unstemmed |
Pb nanospheres in ancient zircon yield model ages for zircon formation and Pb mobilization |
title_sort |
pb nanospheres in ancient zircon yield model ages for zircon formation and pb mobilization |
publisher |
Nature Publishing Group UK |
publishDate |
2019 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6757063/ http://www.ncbi.nlm.nih.gov/pubmed/31548570 https://doi.org/10.1038/s41598-019-49882-8 |
long_lat |
ENVELOPE(-58.440,-58.440,-62.167,-62.167) |
geographic |
East Antarctica Napier |
geographic_facet |
East Antarctica Napier |
genre |
Antarc* Antarctica East Antarctica Enderby Land |
genre_facet |
Antarc* Antarctica East Antarctica Enderby Land |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6757063/ http://www.ncbi.nlm.nih.gov/pubmed/31548570 http://dx.doi.org/10.1038/s41598-019-49882-8 |
op_rights |
© The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
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CC-BY |
op_doi |
https://doi.org/10.1038/s41598-019-49882-8 |
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