Articles | Volume 3, issue 1
https://doi.org/10.5194/gchron-3-247-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gchron-3-247-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
On the treatment of discordant detrital zircon U–Pb data
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
Related authors
Pieter Vermeesch, Tim Band, Jiangping He, Rex Galbraith, and Andrew Carter
EGUsphere, https://doi.org/10.5194/egusphere-2025-4948, https://doi.org/10.5194/egusphere-2025-4948, 2025
This preprint is open for discussion and under review for Geochronology (GChron).
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geochron@home is an open-source platform that makes fission track dating more transparent and reliable. It combines a virtual microscope with an online database to share images and data openly, following FAIR principles. Researchers can analyse tracks privately, archive data for peer review, teach students, or involve citizen scientists. By improving data access and reproducibility, geochron@home helps build trust and supports future advances in Earth science.
Pieter Vermeesch, Noah McLean, Anton Vaks, Tzahi Golan, Sebastian F. M. Breitenbach, and Randall Parrish
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U–Pb dating of cave sediments has provided important new time constraints on the evolution of cave-dwelling organisms (including early humans) and of Earth's climate during the past 5 Myr. This paper shows that the most common type of U–Pb dating, which uses 238U and 206Pb, can be inaccurate beyond ca. 2 Myr ago. It proposes an alternative type of U–Pb dating, using 235U and 207Pb, as a more accurate alternative.
Pieter Vermeesch
Geochronology, 6, 397–407, https://doi.org/10.5194/gchron-6-397-2024, https://doi.org/10.5194/gchron-6-397-2024, 2024
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The age of some geological materials can be estimated from the ratio of certain radiogenic "daughter" isotopes to their radioactive "parent". However, in many cases, the age estimation process is complicated by the presence of an inherited component of non-radiogenic daughter isotopes. This paper presents an improved algorithm to estimate the radiogenic and non-radiogenic components, either separately or jointly.
Pieter Vermeesch, Yuntao Tian, Jae Schwanethal, and Yannick Buret
Geochronology, 5, 323–332, https://doi.org/10.5194/gchron-5-323-2023, https://doi.org/10.5194/gchron-5-323-2023, 2023
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The U–Th–He method is a technique to determine the cooling history of minerals. Traditional approaches to U–Th–He dating are time-consuming and require handling strong acids and radioactive solutions. This paper presents an alternative approach in which samples are irradiated with protons and subsequently analysed by laser ablation mass spectrometry. Unlike previous in situ U–Th–He dating attempts, the new method does not require any absolute concentration measurements of U, Th, or He.
Alex Lipp and Pieter Vermeesch
Geochronology, 5, 263–270, https://doi.org/10.5194/gchron-5-263-2023, https://doi.org/10.5194/gchron-5-263-2023, 2023
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We propose using the Wasserstein-2 distance (W2) as an alternative to the widely used Kolmogorov–Smirnov (KS) statistic for analysing distributional data in geochronology. W2 measures the horizontal distance between observations, while KS measures vertical differences in cumulative distributions. Using case studies, we find that W2 is preferable in scenarios where the absolute age differences in observations provide important geological information. W2 has been added to the R package IsoplotR.
Matthew Fox, Adam G. G. Smith, Pieter Vermeesch, Kerry Gallagher, and Andrew Carter
Geochronology Discuss., https://doi.org/10.5194/gchron-2022-23, https://doi.org/10.5194/gchron-2022-23, 2022
Publication in GChron not foreseen
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The Great Unconformity represents an enormous amount of time lost from the sedimentary record. Its origin is debated, in part, due to different approaches used to interpret zircon (U–Th)/He ages. This thermochronometric system is ideal for this problem because the temperature sensitivity varies according to radiation damage. Here we explore the uncertainty associated with the radiation damage model and show how this limits our ability to resolve the origin of the Great Unconformity.
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Geochronology, 4, 561–576, https://doi.org/10.5194/gchron-4-561-2022, https://doi.org/10.5194/gchron-4-561-2022, 2022
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Secondary ion mass spectrometry (SIMS) is the oldest and most sensitive analytical technique for in situ U–Pb geochronology. This paper introduces a new algorithm for SIMS data reduction that treats data as
compositional data, which means that the relative abundances of 204Pb, 206Pb, 207Pb, and 238Pb are processed within a tetrahedral data space or
simplex. The new method is implemented in an eponymous computer programme that is compatible with the two dominant types of SIMS instruments.
Yang Li and Pieter Vermeesch
Geochronology, 3, 415–420, https://doi.org/10.5194/gchron-3-415-2021, https://doi.org/10.5194/gchron-3-415-2021, 2021
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A conventional isochron is a straight-line fit to two sets of isotopic ratios, D/d and P/d, where P is the radioactive parent, D is the radiogenic daughter, and d is a second isotope of the daughter element. The slope of this line is proportional to the age of the system. An inverse isochron is a linear fit through d/D and P/D. The horizontal intercept of this line is inversely proportional to the age. The latter approach is preferred when d<D, which is the case in Re–Os and K–Ca geochronology.
Pieter Vermeesch, Tim Band, Jiangping He, Rex Galbraith, and Andrew Carter
EGUsphere, https://doi.org/10.5194/egusphere-2025-4948, https://doi.org/10.5194/egusphere-2025-4948, 2025
This preprint is open for discussion and under review for Geochronology (GChron).
Short summary
Short summary
geochron@home is an open-source platform that makes fission track dating more transparent and reliable. It combines a virtual microscope with an online database to share images and data openly, following FAIR principles. Researchers can analyse tracks privately, archive data for peer review, teach students, or involve citizen scientists. By improving data access and reproducibility, geochron@home helps build trust and supports future advances in Earth science.
Pieter Vermeesch, Noah McLean, Anton Vaks, Tzahi Golan, Sebastian F. M. Breitenbach, and Randall Parrish
Geochronology, 7, 459–473, https://doi.org/10.5194/gchron-7-459-2025, https://doi.org/10.5194/gchron-7-459-2025, 2025
Short summary
Short summary
U–Pb dating of cave sediments has provided important new time constraints on the evolution of cave-dwelling organisms (including early humans) and of Earth's climate during the past 5 Myr. This paper shows that the most common type of U–Pb dating, which uses 238U and 206Pb, can be inaccurate beyond ca. 2 Myr ago. It proposes an alternative type of U–Pb dating, using 235U and 207Pb, as a more accurate alternative.
Pieter Vermeesch
Geochronology, 6, 397–407, https://doi.org/10.5194/gchron-6-397-2024, https://doi.org/10.5194/gchron-6-397-2024, 2024
Short summary
Short summary
The age of some geological materials can be estimated from the ratio of certain radiogenic "daughter" isotopes to their radioactive "parent". However, in many cases, the age estimation process is complicated by the presence of an inherited component of non-radiogenic daughter isotopes. This paper presents an improved algorithm to estimate the radiogenic and non-radiogenic components, either separately or jointly.
Pieter Vermeesch, Yuntao Tian, Jae Schwanethal, and Yannick Buret
Geochronology, 5, 323–332, https://doi.org/10.5194/gchron-5-323-2023, https://doi.org/10.5194/gchron-5-323-2023, 2023
Short summary
Short summary
The U–Th–He method is a technique to determine the cooling history of minerals. Traditional approaches to U–Th–He dating are time-consuming and require handling strong acids and radioactive solutions. This paper presents an alternative approach in which samples are irradiated with protons and subsequently analysed by laser ablation mass spectrometry. Unlike previous in situ U–Th–He dating attempts, the new method does not require any absolute concentration measurements of U, Th, or He.
Alex Lipp and Pieter Vermeesch
Geochronology, 5, 263–270, https://doi.org/10.5194/gchron-5-263-2023, https://doi.org/10.5194/gchron-5-263-2023, 2023
Short summary
Short summary
We propose using the Wasserstein-2 distance (W2) as an alternative to the widely used Kolmogorov–Smirnov (KS) statistic for analysing distributional data in geochronology. W2 measures the horizontal distance between observations, while KS measures vertical differences in cumulative distributions. Using case studies, we find that W2 is preferable in scenarios where the absolute age differences in observations provide important geological information. W2 has been added to the R package IsoplotR.
Matthew Fox, Adam G. G. Smith, Pieter Vermeesch, Kerry Gallagher, and Andrew Carter
Geochronology Discuss., https://doi.org/10.5194/gchron-2022-23, https://doi.org/10.5194/gchron-2022-23, 2022
Publication in GChron not foreseen
Short summary
Short summary
The Great Unconformity represents an enormous amount of time lost from the sedimentary record. Its origin is debated, in part, due to different approaches used to interpret zircon (U–Th)/He ages. This thermochronometric system is ideal for this problem because the temperature sensitivity varies according to radiation damage. Here we explore the uncertainty associated with the radiation damage model and show how this limits our ability to resolve the origin of the Great Unconformity.
Pieter Vermeesch
Geochronology, 4, 561–576, https://doi.org/10.5194/gchron-4-561-2022, https://doi.org/10.5194/gchron-4-561-2022, 2022
Short summary
Short summary
Secondary ion mass spectrometry (SIMS) is the oldest and most sensitive analytical technique for in situ U–Pb geochronology. This paper introduces a new algorithm for SIMS data reduction that treats data as
compositional data, which means that the relative abundances of 204Pb, 206Pb, 207Pb, and 238Pb are processed within a tetrahedral data space or
simplex. The new method is implemented in an eponymous computer programme that is compatible with the two dominant types of SIMS instruments.
Yang Li and Pieter Vermeesch
Geochronology, 3, 415–420, https://doi.org/10.5194/gchron-3-415-2021, https://doi.org/10.5194/gchron-3-415-2021, 2021
Short summary
Short summary
A conventional isochron is a straight-line fit to two sets of isotopic ratios, D/d and P/d, where P is the radioactive parent, D is the radiogenic daughter, and d is a second isotope of the daughter element. The slope of this line is proportional to the age of the system. An inverse isochron is a linear fit through d/D and P/D. The horizontal intercept of this line is inversely proportional to the age. The latter approach is preferred when d<D, which is the case in Re–Os and K–Ca geochronology.
Cited articles
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Nemchin, A. A. and Cawood, P. A.: Discordance of the U–Pb system in detrital zircons: Implication for provenance studies of sedimentary rocks, Sediment. Geol., 182, 143–162, https://doi.org/10.1016/j.sedgeo.2005.07.011, 2005. a
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Short summary
This paper shows that the current practice of filtering discordant U–Pb data based on the relative difference between the 206Pb/238U and 207Pb/206Pb ages is just one of several possible approaches to the problem and demonstrably not the best one. An alternative approach is to define discordance in terms of isotopic composition, as a log ratio distance between the measurement and the concordia line. Application to real data indicates that this reduces the positive bias of filtered age spectra.
This paper shows that the current practice of filtering discordant U–Pb data based on the...