Articles | Volume 5, issue 1
https://doi.org/10.5194/gchron-5-91-2023
© Author(s) 2023. 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-5-91-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Feb 2023
Research article |
| 07 Feb 2023
Calculation of uncertainty in the (U–Th) ∕ He system
Peter E. Martin
CORRESPONDING AUTHOR
Department of Geological Sciences, University of Colorado, Boulder, CO
80309, USA
James R. Metcalf
Department of Geological Sciences, University of Colorado, Boulder, CO
80309, USA
Rebecca M. Flowers
Department of Geological Sciences, University of Colorado, Boulder, CO
80309, USA
Related authors
No articles found.
Spencer D. Zeigler, James R. Metcalf, and Rebecca M. Flowers
EGUsphere, https://doi.org/10.5194/egusphere-2022-1005, https://doi.org/10.5194/egusphere-2022-1005, 2022
Short summary
Short summary
(U-Th)/He dating relies on proper characterization of apatite crystal dimensions so that eU concentrations and dates can be calculated accurately and precisely, but there is systematic error and uncertainty on geometric measurements. By comparing 2D microscopy to “true” 3D measurements, we present a simple solution to correcting the error and quantifying the geometric uncertainty on eU and dates. Including this geometric correction and uncertainty matters for data evaluation and interpretation.
Alison R. Duvall, Sarah A. Harbert, Phaedra Upton, Gregory E. Tucker, Rebecca M. Flowers, and Camille Collett
Earth Surf. Dynam., 8, 177–194, https://doi.org/10.5194/esurf-8-177-2020, https://doi.org/10.5194/esurf-8-177-2020, 2020
Short summary
Short summary
In this study, we examine river patterns and the evolution of the landscape within the Marlborough Fault System, South Island, New Zealand, where the Australian and Pacific tectonic plates collide. We find that faulting, uplift, river capture and the long-lived nature of the drainage network all dictate river patterns at this site. Based on these results and a wealth of previous geologic studies, we propose two broad stages of landscape evolution over the last 25 million years of orogenesis.
Related subject area
Geochronological data analysis/statistics/modelling
Technical note: colab_zirc_dims: a Google Colab-compatible toolset for automated and semi-automated measurement of mineral grains in laser ablation–inductively coupled plasma–mass spectrometry images using deep learning models
Bayesian age–depth modelling applied to varve and radiometric dating to optimize the transfer of an existing high-resolution chronology to a new composite sediment profile from Holzmaar (West Eifel Volcanic Field, Germany)
Short communication: age2exhume – a MATLAB/Python script to calculate steady-state vertical exhumation rates from thermochronometric ages and application to the Himalaya
U and Th content in magnetite and Al spinel obtained by wet chemistry and laser ablation methods: implication for (U–Th) ∕ He thermochronometer
In situ LA-ICPMS U–Pb dating of sulfates: applicability of carbonate reference materials as matrix-matched standards
An algorithm for U–Pb geochronology by secondary ion mass spectrometry
Technical note: Rapid phase identification of apatite and zircon grains for geochronology using X-ray micro-computed tomography
Simulating sedimentary burial cycles – Part 2: Elemental-based multikinetic apatite fission-track interpretation and modelling techniques illustrated using examples from northern Yukon
sandbox – creating and analysing synthetic sediment sections with R
Improving age–depth relationships by using the LANDO (“Linked age and depth modeling”) model ensemble
How many grains are needed for quantifying catchment erosion from tracer thermochronology?
Short communication: Inverse isochron regression for Re–Os, K–Ca and other chronometers
Technical note: Analytical protocols and performance for apatite and zircon (U–Th) ∕ He analysis on quadrupole and magnetic sector mass spectrometer systems between 2007 and 2020
Simulating sedimentary burial cycles – Part 1: Investigating the role of apatite fission track annealing kinetics using synthetic data
The closure temperature(s) of zircon Raman dating
On the treatment of discordant detrital zircon U–Pb data
An evaluation of Deccan Traps eruption rates using geochronologic data
geoChronR – an R package to model, analyze, and visualize age-uncertain data
Development of a multi-method chronology spanning the Last Glacial Interval from Orakei maar lake, Auckland, New Zealand
Robust isochron calculation
Resolving the timescales of magmatic and hydrothermal processes associated with porphyry deposit formation using zircon U–Pb petrochronology
Seasonal deposition processes and chronology of a varved Holocene lake sediment record from Chatyr Kol lake (Kyrgyz Republic)
Unifying the U–Pb and Th–Pb methods: joint isochron regression and common Pb correction
Exploring the advantages and limitations of in situ U–Pb carbonate geochronology using speleothems
Michael C. Sitar and Ryan J. Leary
Geochronology, 5, 109–126, https://doi.org/10.5194/gchron-5-109-2023, https://doi.org/10.5194/gchron-5-109-2023, 2023
Short summary
Short summary
We developed code to automatically and semi-automatically measure dimensions of detrital mineral grains in reflected-light images saved at laser ablation–inductively coupled plasma–mass spectrometry facilities that use Chromium targeting software. Our code uses trained deep learning models to segment grain images with greater accuracy than is achievable using other segmentation techniques. We implement our code in Jupyter notebooks which can also be run online via Google Colab.
Stella Birlo, Wojciech Tylmann, and Bernd Zolitschka
Geochronology, 5, 65–90, https://doi.org/10.5194/gchron-5-65-2023, https://doi.org/10.5194/gchron-5-65-2023, 2023
Short summary
Short summary
Sediment cores from the volcanic lake Holzmaar provide a very precise chronology based on tree-ring-like annual laminations or varves. We statistically combine this varve chronology with radiometric dating and tested three different methods to upgrade the age–depth model. However, only one of the three methods tested improved the dating accuracy considerably. With this work, an overview of different age integration methods is discussed and made available for increased future demands.
Peter van der Beek and Taylor F. Schildgen
Geochronology, 5, 35–49, https://doi.org/10.5194/gchron-5-35-2023, https://doi.org/10.5194/gchron-5-35-2023, 2023
Short summary
Short summary
Thermochronometric data can provide unique insights into the patterns of rock exhumation and the driving mechanisms of landscape evolution. Several well-established thermal models allow for a detailed exploration of how cooling rates evolved in a limited area or along a transect, but more regional analyses have been challenging. We present age2exhume, a thermal model that can be used to rapidly provide a synoptic overview of exhumation rates from large regional thermochronologic datasets.
Marianna Corre, Arnaud Agranier, Martine Lanson, Cécile Gautheron, Fabrice Brunet, and Stéphane Schwartz
Geochronology, 4, 665–681, https://doi.org/10.5194/gchron-4-665-2022, https://doi.org/10.5194/gchron-4-665-2022, 2022
Short summary
Short summary
This study is focused on the accurate measurement of U and Th by wet chemistry and laser ablation methods to improve (U–Th)/He dating of magnetite and spinel. The low U–Th content and the lack of specific U–Th standards significantly limit the accuracy of (U–Th)/He dating. Obtained U–Th results on natural and synthetic magnetite and aluminous spinel samples analyzed by wet chemistry methods and LA-ICP-MS sampling have important implications for the (U–Th)/He method and dates interpretation.
Aratz Beranoaguirre, Iuliana Vasiliev, and Axel Gerdes
Geochronology, 4, 601–616, https://doi.org/10.5194/gchron-4-601-2022, https://doi.org/10.5194/gchron-4-601-2022, 2022
Short summary
Short summary
U–Pb dating by the in situ laser ablation mass spectrometry (LA-ICPMS) technique requires reference materials of the same nature as the samples to be analysed. Here, we have explored the suitability of using carbonate materials as a reference for sulfates, since there is no sulfate reference material. The results we obtained are satisfactory, and thus, from now on, the sulfates can also be analysed.
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.
Emily H. G. Cooperdock, Florian Hofmann, Ryley M. C. Tibbetts, Anahi Carrera, Aya Takase, and Aaron J. Celestian
Geochronology, 4, 501–515, https://doi.org/10.5194/gchron-4-501-2022, https://doi.org/10.5194/gchron-4-501-2022, 2022
Short summary
Short summary
Apatite and zircon are the most widely used minerals for dating rocks, but they can be difficult to identify in some crushed rock samples. Incorrect mineral identification results in wasted analytical resources and inaccurate data. We show how X-ray computed tomography can be used to efficiently and accurately distinguish apatite from zircon based on density variations, and provide non-destructive 3D grain-specific size, shape, and inclusion information for improved data quality.
Dale R. Issler, Kalin T. McDannell, Paul B. O'Sullivan, and Larry S. Lane
Geochronology, 4, 373–397, https://doi.org/10.5194/gchron-4-373-2022, https://doi.org/10.5194/gchron-4-373-2022, 2022
Short summary
Short summary
Phanerozoic sedimentary rocks of northern Canada have compositionally heterogeneous detrital apatite with high age dispersion caused by differential thermal annealing. Discrete apatite fission track kinetic populations with variable annealing temperatures are defined using elemental data but are poorly resolved using conventional parameters. Inverse thermal modelling of samples from northern Yukon reveals a record of multiple heating–cooling cycles consistent with geological constraints.
Michael Dietze, Sebastian Kreutzer, Margret C. Fuchs, and Sascha Meszner
Geochronology, 4, 323–338, https://doi.org/10.5194/gchron-4-323-2022, https://doi.org/10.5194/gchron-4-323-2022, 2022
Short summary
Short summary
The R package sandbox is a collection of functions that allow the creation, sampling and analysis of fully virtual sediment sections, like having a virtual twin of real-world deposits. This article introduces the concept, features, and workflows required to use sandbox. It shows how a real-world sediment section can be mapped into the model and subsequently addresses a series of theoretical and practical questions, exploiting the flexibility of the model framework.
Gregor Pfalz, Bernhard Diekmann, Johann-Christoph Freytag, Liudmila Syrykh, Dmitry A. Subetto, and Boris K. Biskaborn
Geochronology, 4, 269–295, https://doi.org/10.5194/gchron-4-269-2022, https://doi.org/10.5194/gchron-4-269-2022, 2022
Short summary
Short summary
We use age–depth modeling systems to understand the relationship between age and depth in lake sediment cores. However, depending on which modeling system we use, the model results may vary. We provide a tool to link different modeling systems in an interactive computational environment and make their results comparable. We demonstrate the power of our tool by highlighting three case studies in which we test our application for single-sediment cores and a collection of multiple sediment cores.
Andrea Madella, Christoph Glotzbach, and Todd A. Ehlers
Geochronology, 4, 177–190, https://doi.org/10.5194/gchron-4-177-2022, https://doi.org/10.5194/gchron-4-177-2022, 2022
Short summary
Short summary
Cooling ages date the time at which minerals cross a certain isotherm on the way up to Earth's surface. Such ages can be measured from bedrock material and river sand. If spatial variations in bedrock ages are known in a river catchment, the spatial distribution of erosion can be inferred from the distribution of the ages measured from the river sand grains. Here we develop a new tool to help such analyses, with particular emphasis on quantifying uncertainties due to sample size.
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.
Cécile Gautheron, Rosella Pinna-Jamme, Alexis Derycke, Floriane Ahadi, Caroline Sanchez, Frédéric Haurine, Gael Monvoisin, Damien Barbosa, Guillaume Delpech, Joseph Maltese, Philippe Sarda, and Laurent Tassan-Got
Geochronology, 3, 351–370, https://doi.org/10.5194/gchron-3-351-2021, https://doi.org/10.5194/gchron-3-351-2021, 2021
Short summary
Short summary
Apatite and zircon (U–Th) / He thermochronology is now a mainstream tool to reconstruct Earth's evolution through the history of cooling and exhumation over the first dozen kilometers. The geological implications of these data rely on the precision of measurements of He, U, Th, and Sm contents in crystals. This technical note documents the methods for He thermochronology developed at the GEOPS laboratory, Paris-Saclay University, that allow (U–Th) / He data to be obtained with precision.
Kalin T. McDannell and Dale R. Issler
Geochronology, 3, 321–335, https://doi.org/10.5194/gchron-3-321-2021, https://doi.org/10.5194/gchron-3-321-2021, 2021
Short summary
Short summary
We generated a synthetic dataset applying published kinetic models and distinct annealing kinetics for the apatite fission track and (U–Th)/He methods using a predetermined thermal history. We then tested how well the true thermal history could be recovered under different data interpretation schemes and geologic constraint assumptions using the Bayesian QTQt software. Our results demonstrate that multikinetic data increase time–temperature resolution and can constrain complex thermal histories.
Birk Härtel, Raymond Jonckheere, Bastian Wauschkuhn, and Lothar Ratschbacher
Geochronology, 3, 259–272, https://doi.org/10.5194/gchron-3-259-2021, https://doi.org/10.5194/gchron-3-259-2021, 2021
Short summary
Short summary
We carried out thermal annealing experiments between 500 and 1000 °C to determine the closure temperature of radiation-damage annealing in zircon (ZrSiO4). Our results show that the different Raman bands of zircon respond differently to annealing. The repair is highest for the external rotation Raman band near 356.6 cm−1. The closure temperature estimates range from 250 to 370 °C for different bands. The differences in closure temperatures offer the prospect of multi-T zircon Raman dating.
Pieter Vermeesch
Geochronology, 3, 247–257, https://doi.org/10.5194/gchron-3-247-2021, https://doi.org/10.5194/gchron-3-247-2021, 2021
Short summary
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.
Blair Schoene, Michael P. Eddy, C. Brenhin Keller, and Kyle M. Samperton
Geochronology, 3, 181–198, https://doi.org/10.5194/gchron-3-181-2021, https://doi.org/10.5194/gchron-3-181-2021, 2021
Short summary
Short summary
We compare two published U–Pb and 40Ar / 39Ar geochronologic datasets to produce eruption rate models for the Deccan Traps large igneous province. Applying the same approach to each dataset, the resulting models agree well, but the higher-precision U–Pb dataset results in a more detailed eruption model than the lower-precision 40Ar / 39Ar data. We explore sources of geologic uncertainty and reiterate the importance of systematic uncertainties in comparing U–Pb and 40Ar / 39Ar datasets.
Nicholas P. McKay, Julien Emile-Geay, and Deborah Khider
Geochronology, 3, 149–169, https://doi.org/10.5194/gchron-3-149-2021, https://doi.org/10.5194/gchron-3-149-2021, 2021
Short summary
Short summary
This paper describes geoChronR, an R package that streamlines the process of quantifying age uncertainties, propagating uncertainties through several common analyses, and visualizing the results. In addition to describing the structure and underlying theory of the package, we present five real-world use cases that illustrate common workflows in geoChronR. geoChronR is built on the Linked PaleoData framework, is open and extensible, and we welcome feedback and contributions from the community.
Leonie Peti, Kathryn E. Fitzsimmons, Jenni L. Hopkins, Andreas Nilsson, Toshiyuki Fujioka, David Fink, Charles Mifsud, Marcus Christl, Raimund Muscheler, and Paul C. Augustinus
Geochronology, 2, 367–410, https://doi.org/10.5194/gchron-2-367-2020, https://doi.org/10.5194/gchron-2-367-2020, 2020
Short summary
Short summary
Orakei Basin – a former maar lake in Auckland, New Zealand – provides an outstanding sediment record over the last ca. 130 000 years, but an age model is required to allow the reconstruction of climate change and volcanic eruptions contained in the sequence. To construct a relationship between depth in the sediment core and age of deposition, we combined tephrochronology, radiocarbon dating, luminescence dating, and the relative intensity of the paleomagnetic field in a Bayesian age–depth model.
Roger Powell, Eleanor C. R. Green, Estephany Marillo Sialer, and Jon Woodhead
Geochronology, 2, 325–342, https://doi.org/10.5194/gchron-2-325-2020, https://doi.org/10.5194/gchron-2-325-2020, 2020
Short summary
Short summary
The standard approach to isochron calculation assumes that the distribution of uncertainties on the data arising from isotopic analysis is strictly Gaussian. This excludes datasets that have more scatter, even though many appear to have age significance. Our new approach requires only that the central part of the uncertainty distribution of the data defines a "spine" in the trend of the data. A robust statistics approach is used to locate the spine, and an implementation in Python is given.
Simon J. E. Large, Jörn-Frederik Wotzlaw, Marcel Guillong, Albrecht von Quadt, and Christoph A. Heinrich
Geochronology, 2, 209–230, https://doi.org/10.5194/gchron-2-209-2020, https://doi.org/10.5194/gchron-2-209-2020, 2020
Short summary
Short summary
The integration of zircon geochemistry and U–Pb geochronology (petrochronology) allows us to improve our understanding of magmatic processes. Here we could reconstruct the ~300 kyr evolution of the magma reservoir that sourced the magmas, fluids and metals to form the Batu Hijau porphyry Cu–Au deposit. The application of in situ LA-ICP-MS and high-precision CA–ID–TIMS geochronology to the same zircons further allowed an assessment of the strengths and limitations of the different techniques.
Julia Kalanke, Jens Mingram, Stefan Lauterbach, Ryskul Usubaliev, Rik Tjallingii, and Achim Brauer
Geochronology, 2, 133–154, https://doi.org/10.5194/gchron-2-133-2020, https://doi.org/10.5194/gchron-2-133-2020, 2020
Short summary
Short summary
Our study presents the first seasonally laminated (varved) sediment record covering almost the entire Holocene in high mountainous arid Central Asia. The established floating varve chronology is confirmed by two terrestrial radiocarbon dates, whereby aquatic radiocarbon dates reveal decreasing reservoir ages up core. Changes in seasonal deposition characteristics are attributed to changes in runoff and precipitation and/or to evaporative summer conditions.
Pieter Vermeesch
Geochronology, 2, 119–131, https://doi.org/10.5194/gchron-2-119-2020, https://doi.org/10.5194/gchron-2-119-2020, 2020
Short summary
Short summary
The U–Pb method is one of the most powerful and versatile methods in the geochronological toolbox. With two isotopes of uranium decaying to two different isotopes of lead, the U–Pb method offers an internal quality control that is absent from most other geochronological techniques. U-bearing minerals often contain significant amounts of Th, which decays to a third Pb isotope. This paper presents an algorithm to jointly process all three chronometers at once.
Jon Woodhead and Joseph Petrus
Geochronology, 1, 69–84, https://doi.org/10.5194/gchron-1-69-2019, https://doi.org/10.5194/gchron-1-69-2019, 2019
Short summary
Short summary
Recently developed methods for in situ U–Pb age determination in carbonates have found widespread application, but the benefits and limitations of the method over bulk analysis approaches have yet to be fully explored. Here we use speleothems – cave carbonates such as stalagmites and flowstones – to investigate the utility of these in situ dating methodologies for challenging matrices with low U and Pb contents and predominantly late Cenozoic ages.
Cited articles
Anderson, G. M.: Error propagation by the Monte Carlo method in geochemical
calculations, Geochim. Cosmochim. Ac., 40, 1533–1538,
https://doi.org/10.1016/0016-7037(76)90092-2, 1976.
Azzalini, A.: A Class of Distributions Which Includes the Normal Ones,
Scand. J. Stat., 12, 171–178, 1985.
Azzalini, A. and Capitanio, A.: Statistical applications of the multivariate
skew normal distribution, J. Roy. Stat. Soc. Ser. B, 61, 579–602,
https://doi.org/10.1111/1467-9868.00194, 1999.
Bevington, P. and Robinson, D. K.: Data Reduction and Error Analysis for the
Physical Sciences, 3rd Edn., McGraw-Hill Education, 344 pp., ISBN 13: 9780071199261, 2003.
Brown, R. W., Beucher, R., Roper, S., Persano, C., Stuart, F., and
Fitzgerald, P.: Natural age dispersion arising from the analysis of broken
crystals, Part I: Theoretical basis and implications for the apatite
(U–Th)
Cooperdock, E. H. G., Ketcham, R. A., and Stockli, D. F.: Resolving the
effects of 2-D versus 3-D grain measurements on apatite
(U–Th)
Evans, N. J., McInnes, B. I. A., Squelch, A. P., Austin, P. J., McDonald, B.
J., and Wu, Q.: Application of X-ray micro-computed tomography in (U–Th)
Farley, K. A., Wolf, R. A., and Silver, L. T.: The effects of long
alpha-stopping distances on (U–Th)
Farley, K. A., Shuster, D. L., and Ketcham, R. A.: U and Th zonation in
apatite observed by laser ablation ICPMS, and implications for the
(U–Th)
Fitzgerald, P. G., Baldwin, S. L., Webb, L. E., and O'Sullivan, P. B.:
Interpretation of (U–Th)
Flowers, R. M., Ketcham, R. A., Shuster, D. L., and Farley, K. A.: Apatite
(U–Th)
Flowers, R. M., Zeitler, P. K., Danišík, M., Reiners, P. W.,
Gautheron, C., Ketcham, R. A., Metcalf, J. R., Stockli, D.
F., Enkelmann, E., and Brown, R. W.: (U-Th) = He chronology:
Part 1. Data, uncertainty, and reporting, GSA Bull.,
30, https://doi.org/10.1130/B36266.1, 2022.
Flowers, R. M., Zeitler, P. K., Danišík, M., Reiners, P. W.,
Gautheron, C., Ketcham, R. A., Metcalf, J. R., Stockli, D. F., Enkelmann,
E., and Brown, R. W.: (U-Th)
Gallagher, K.: Transdimensional inverse thermal history modeling for
quantitative thermochronology, J. Geophys. Res.-Sol. Ea.,
117, B02408, https://doi.org/10.1029/2011JB008825, 2012.
Gautheron, C., Tassan-Got, L., Barbarand, J., and Pagel, M.: Effect of
alpha-damage annealing on apatite (U–Th)
Glotzbach, C., Lang, K. A., Avdievitch, N. N., and Ehlers, T. A.: Increasing
the accuracy of (U-Th(-Sm))
Guenthner, W. R., Reiners, P. W., Ketcham, R. A., Nasdala, L., and Giester,
G.: Helium diffusion in natural zircon: Radiation damage, anisotropy, and
the interpretation of zircon (U-Th)
Herman, F., Braun, J., Senden, T. J., and Dunlap, W. J.: (U–Th)
Hiess, J., Condon, D. J., McLean, N., and Noble, S. R.: 238U
Hourigan, J. K., Reiners, P. W., and Brandon, M. T.: U-Th zonation-dependent
alpha-ejection in (U-Th)
House, M. A., Farley, K. A., and Stockli, D.: Helium chronometry of apatite
and titanite using Nd-YAG laser heating, Earth Pl. Sc.
Lett., 183, 365–368, https://doi.org/10.1016/S0012-821X(00)00286-7, 2000.
Johnstone, S., Hourigan, J., and Gallagher, C.: LA-ICP-MS depth profile
analysis of apatite: Protocol and implications for (U–Th)
Ketcham, R. A.: Forward and Inverse Modeling of Low-Temperature
Thermochronometry Data, Rev. Mineral. Geochem., 58,
275–314, https://doi.org/10.2138/rmg.2005.58.11, 2005.
Ketcham, R. A., Gautheron, C., and Tassan-Got, L.: Accounting for long
alpha-particle stopping distances in (U–Th–Sm)
Ketcham, R. A., Tremblay, M., Abbey, A., Baughman, J., Cooperdock, E.,
Jepson, G., Murray, K., Odlum, M., Stanley, J., and Thurston, O.: Report
from the 17th International Conference on Thermochronology, Earth Space
Sci. Open Ar., 1–20, https://doi.org/10.1002/essoar.10511082.1, 2022.
Martin, P.: HeCalc (1.0.1), Zenodo [code], https://doi.org/10.5281/zenodo.7453426, 2022.
McLean, N. M., Bowring, J. F., and Bowring, S. A.: An algorithm for U-Pb
isotope dilution data reduction and uncertainty propagation, Geochem.
Geophy. Geosy., 12, Q0AA18, https://doi.org/10.1029/2010GC003478, 2011.
Meesters, A. G. C. A. and Dunai, T. J.: A noniterative solution of the
(U-Th)
Murray, K. E., Orme, D. A., and Reiners, P. W.: Effects of U–Th-rich grain
boundary phases on apatite helium ages, Chem. Geol., 390, 135–151,
https://doi.org/10.1016/j.chemgeo.2014.09.023, 2014.
O'Hagan, A. and Leonard, T.: Bayes estimation subject to uncertainty about
parameter constraints, Biometrika, 63, 201–203,
https://doi.org/10.1093/biomet/63.1.201, 1976.
Peak, B. A., Flowers, R. M., Macdonald, F. A., and Cottle, J. M.: Zircon
(U-Th)
Possolo, A. and Iyer, H. K.: Invited Article: Concepts and tools for the
evaluation of measurement uncertainty, Rev. Sci. Instrum., 88,
011301, https://doi.org/10.1063/1.4974274, 2017.
Sturrock, C. P., Flowers, R. M., and Macdonald, F. A.: The Late Great
Unconformity of the Central Canadian Shield, Geochem. Geophy.
Geosy., 22, e2020GC009567, https://doi.org/10.1029/2020GC009567, 2021.
Wernicke, R. S. and Lippolt, H. J.: Dating of vein Specularite using
internal (U + Th)
Wolf, R. A., Farley, K. A., and Silver, L. T.: Helium diffusion and
low-temperature thermochronometry of apatite, Geochim. Cosmochim. Ac., 60, 4231–4240, https://doi.org/10.1016/S0016-7037(96)00192-5, 1996.
Wübbeler, G., Harris, P. M., Cox, M. G., and Elster, C.: A two-stage
procedure for determining the number of trials in the application of a Monte
Carlo method for uncertainty evaluation, Metrologia, 47, 317–324,
https://doi.org/10.1088/0026-1394/47/3/023, 2010.
Zeigler, S. D., Metcalf, J. R., and Flowers, R. M.: A practical method for assigning uncertainty and improving the accuracy of alpha-ejection corrections and eU concentrations in apatite (U-Th)
Zeitler, P. K., Herczeg, A. L., McDougall, I., and Honda, M.: U-Th-He dating
of apatite: A potential thermochronometer, Geochim. Cosmochim. Ac.,
51, 2865–2868, https://doi.org/10.1016/0016-7037(87)90164-5, 1987.
Zeitler, P. K., Enkelmann, E., Thomas, J. B., Watson, E. B., Ancuta, L. D.,
and Idleman, B. D.: Solubility and trapping of helium in apatite, Geochim. Cosmochim. Ac., 209, 1–8, https://doi.org/10.1016/j.gca.2017.03.041,
2017.
Short summary
There is currently no standardized method of performing uncertainty propagation in the (U–Th) / He system, causing data interpretation difficulties. We present two methods of uncertainty propagation and describe free, open-source software (HeCalc) to apply them. Compilation of real data using only analytical uncertainty as well as 2 % and 5 % uncertainties in FT yields respective median relative date uncertainties of 2.9 %, 3.3 %, and 5.0 % for apatites and 1.7 %, 3.3 %, and 5.0 % for zircons.
There is currently no standardized method of performing uncertainty propagation in the...
