Discordance dating: A new approach for dating alteration events

<p>Zircon is the premier geochronometer used to date igneous and metamorphic processes, constrain sediment provenance models, and monitor key events in Earth history such as the growth of continents and the evolution of the biosphere. Zircon U-Pb systematics can be perturbed by the loss or gai...

Full description

Saved in:
Bibliographic Details
Main Authors: J. R. Reimink, R. Beckman, E. Schoonover, M. Lloyd, J. Garber, J. H. F. L. Davies, A. Cerminaro, M. G. Perrot, A. Smye
Format: Article
Language:English
Published: Copernicus Publications 2025-08-01
Series:Geochronology
Online Access:https://gchron.copernicus.org/articles/7/369/2025/gchron-7-369-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849233790675714048
author J. R. Reimink
R. Beckman
E. Schoonover
M. Lloyd
J. Garber
J. H. F. L. Davies
A. Cerminaro
A. Cerminaro
M. G. Perrot
M. G. Perrot
A. Smye
author_facet J. R. Reimink
R. Beckman
E. Schoonover
M. Lloyd
J. Garber
J. H. F. L. Davies
A. Cerminaro
A. Cerminaro
M. G. Perrot
M. G. Perrot
A. Smye
author_sort J. R. Reimink
collection DOAJ
description <p>Zircon is the premier geochronometer used to date igneous and metamorphic processes, constrain sediment provenance models, and monitor key events in Earth history such as the growth of continents and the evolution of the biosphere. Zircon U-Pb systematics can be perturbed by the loss or gain of uranium and/or lead, which can result in disagreement between the apparent radiometric ages of the two U-Pb decay systems – a phenomenon that is commonly termed “discordance”. Discordance in zircon can be difficult to reliably interpret and therefore discordant data are traditionally culled from U-Pb isotopic datasets, particularly detrital zircon datasets. Here we provide a data reduction scheme that extracts reliable age information from discordant zircon U-Pb data found in detrital zircon suites, tracing such processes as fluid flow or contact metamorphism. We provide the template for data reduction and interpretation, a suite of sensitivity tests using synthetic data, and ground-truth this method by analyzing zircons from the well-studied Alta stock metamorphic aureole. Our results show accurate quantification of a <span class="inline-formula">∼</span> 24 Ma in situ zircon alteration event that affected 1.0–2.0 Ga detrital zircons in the Tintic quartzite. The “discordance dating” method outlined here may be widely applicable to a variety of detrital zircon suites where pervasive fluid alteration or metamorphic recrystallization has occurred, even in the absence of concordant U-Pb data.</p>
format Article
id doaj-art-88c95f873fec4cc6a04ca547ce5e040b
institution Kabale University
issn 2628-3697
2628-3719
language English
publishDate 2025-08-01
publisher Copernicus Publications
record_format Article
series Geochronology
spelling doaj-art-88c95f873fec4cc6a04ca547ce5e040b2025-08-20T04:03:25ZengCopernicus PublicationsGeochronology2628-36972628-37192025-08-01736938510.5194/gchron-7-369-2025Discordance dating: A new approach for dating alteration eventsJ. R. Reimink0R. Beckman1E. Schoonover2M. Lloyd3J. Garber4J. H. F. L. Davies5A. Cerminaro6A. Cerminaro7M. G. Perrot8M. G. Perrot9A. Smye10Department of Geosciences, The Pennsylvania State University, University Park, PA, USADepartment of Geosciences, The Pennsylvania State University, University Park, PA, USADepartment of Geosciences, The Pennsylvania State University, University Park, PA, USADepartment of Geosciences, The Pennsylvania State University, University Park, PA, USADepartment of Geosciences, The Pennsylvania State University, University Park, PA, USADépartement des sciences de la Terre et de l'atmosphère/GEOTOP, Université du Québec à Montréal, Montréal, CA, USADepartment of Geosciences, The Pennsylvania State University, University Park, PA, USADepartment of Geosciences, Texas Tech University, 1200 Memorial Circle, Lubbock, TX, USADépartement des sciences de la Terre et de l'atmosphère/GEOTOP, Université du Québec à Montréal, Montréal, CA, USADepartment of Earth and Planetary Sciences, McGill University, Montréal, CA, USADepartment of Geosciences, The Pennsylvania State University, University Park, PA, USA<p>Zircon is the premier geochronometer used to date igneous and metamorphic processes, constrain sediment provenance models, and monitor key events in Earth history such as the growth of continents and the evolution of the biosphere. Zircon U-Pb systematics can be perturbed by the loss or gain of uranium and/or lead, which can result in disagreement between the apparent radiometric ages of the two U-Pb decay systems – a phenomenon that is commonly termed “discordance”. Discordance in zircon can be difficult to reliably interpret and therefore discordant data are traditionally culled from U-Pb isotopic datasets, particularly detrital zircon datasets. Here we provide a data reduction scheme that extracts reliable age information from discordant zircon U-Pb data found in detrital zircon suites, tracing such processes as fluid flow or contact metamorphism. We provide the template for data reduction and interpretation, a suite of sensitivity tests using synthetic data, and ground-truth this method by analyzing zircons from the well-studied Alta stock metamorphic aureole. Our results show accurate quantification of a <span class="inline-formula">∼</span> 24 Ma in situ zircon alteration event that affected 1.0–2.0 Ga detrital zircons in the Tintic quartzite. The “discordance dating” method outlined here may be widely applicable to a variety of detrital zircon suites where pervasive fluid alteration or metamorphic recrystallization has occurred, even in the absence of concordant U-Pb data.</p>https://gchron.copernicus.org/articles/7/369/2025/gchron-7-369-2025.pdf
spellingShingle J. R. Reimink
R. Beckman
E. Schoonover
M. Lloyd
J. Garber
J. H. F. L. Davies
A. Cerminaro
A. Cerminaro
M. G. Perrot
M. G. Perrot
A. Smye
Discordance dating: A new approach for dating alteration events
Geochronology
title Discordance dating: A new approach for dating alteration events
title_full Discordance dating: A new approach for dating alteration events
title_fullStr Discordance dating: A new approach for dating alteration events
title_full_unstemmed Discordance dating: A new approach for dating alteration events
title_short Discordance dating: A new approach for dating alteration events
title_sort discordance dating a new approach for dating alteration events
url https://gchron.copernicus.org/articles/7/369/2025/gchron-7-369-2025.pdf
work_keys_str_mv AT jrreimink discordancedatinganewapproachfordatingalterationevents
AT rbeckman discordancedatinganewapproachfordatingalterationevents
AT eschoonover discordancedatinganewapproachfordatingalterationevents
AT mlloyd discordancedatinganewapproachfordatingalterationevents
AT jgarber discordancedatinganewapproachfordatingalterationevents
AT jhfldavies discordancedatinganewapproachfordatingalterationevents
AT acerminaro discordancedatinganewapproachfordatingalterationevents
AT acerminaro discordancedatinganewapproachfordatingalterationevents
AT mgperrot discordancedatinganewapproachfordatingalterationevents
AT mgperrot discordancedatinganewapproachfordatingalterationevents
AT asmye discordancedatinganewapproachfordatingalterationevents