Articles | Volume 6, issue 4
https://doi.org/10.5194/gchron-6-697-2024
© Author(s) 2024. 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-6-697-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
20 Dec 2024
Research article |
| 20 Dec 2024
| 20 Dec 2024
Interpreting cooling dates and histories from laser ablation in situ (U–Th–Sm) ∕ He thermochronometry: a modelling perspective
Christoph Glotzbach
CORRESPONDING AUTHOR
Department of Geosciences, University of Tübingen, Tübingen, 72076, Germany
Todd A. Ehlers
School of Geographical and Earth Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
Department of Geosciences, University of Tübingen, Tübingen, 72076, Germany
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Cited articles
Anderson, A. J., Hodges, K. V., and van Soest, M. C.: Empirical constraints on the effects of radiation damage on helium diffusion in zircon, Geochim. Cosmochim. Ac., 218, 308–322, https://doi.org/10.1016/j.gca.2017.09.006, 2017.
Boyce, J. W., Hodges, K. V., Olszewski, W. J., Jercinovic, M. J., Carpenter, B. D., and Reiners, P. W.: Laser microprobe (U–Th)/He geochronology, Geochim. Cosmochim. Ac., 70, 3031–3039. https://doi.org/10.1016/j.gca.2006.03.019, 2006.
Bragg, W. H., and Kleeman, R.: On the α particles of radium, and their loss of range in passing through various atoms and molecules, The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 10, 318–340, https://doi.org/10.1080/14786440509463378, 1905.
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)/He thermochronometer, Geochim. Cosmochim. Ac., 122, 478–497, https://doi.org/10.1016/j.gca.2013.05.041, 2013.
Chew, D. M., Petrus, J. A., Kenny, G. G., and McEvoy, N.: Rapid high-resolution U–Pb LA-Q-ICPMS age mapping of zircon, J. Anal. Atom. Spectr., 32, 262–276, https://doi.org/10.1039/C6JA00404K, 2017.
Dunkl, I., Malis, F., Lünsdorf, N. K., Schönig, J., and Von Eynatten, H.: Zircon U-Pb-He Double Dating of Modern Sands From the Inn River Catchment: Assessing Resolution and Potential in a Complex Orogenic Setting, J. Geophys. Res.-Earth., 129, e2023JF007360, https://doi.org/10.1029/2023JF007360, 2024.
Ehlers, T. A.: Crustal Thermal Processes and the Interpretation of Thermochronometer Data, Rev. Mineral. Geochem., 58, 315–350, https://doi.org/10.2138/rmg.2005.58.12, 2005.
Ehlers, T. A. and Farley, K. A.: Apatite (U–Th)/He thermochronometry: methods and applications to problems in tectonic and surface processes, Earth Planet. Sc. Lett., 206, 1–14, https://doi.org/10.1016/S0012-821X(02)01069-5, 2003.
Evans, N. J., McInnes, B. I. A., McDonald, B., Danišík, M., Becker, T., Vermeesch, P., Shelley, M., Marillo-Sialer, E., and Patterson, D. B.: An in situ technique for (U–Th–Sm)/He and U–Pb double dating, J. Anal. Atom. Spectr., 30, 1636–1645, https://doi.org/10.1039/C5JA00085H, 2015.
Danišík, M., McInnes, B. I. A., Kirkland, C. L., McDonald, B. J., Evans, N. J., and Becker, T.: Seeing is believing: Visualization of He distribution in zircon and implications for thermal history reconstruction on single crystals, Sci. Adv., 3, e1601121, https://doi.org/10.1126/sciadv.1601121, 2017.
Falkowski, S., Ehlers, T. A., McQuarrie, N., Glover, C. O., Perez, N. D., and Buford Parks, V. M.: Exhumation and incision of the eastern Central Andes, southern Peru: Low-temperature thermochronology observations, Earth Planet. Sc. Lett., 620, 118299, https://doi.org/10.1016/j.epsl.2023.118299, 2023.
Farley, K. A.: Helium diffusion from apatite: General behavior as illustrated by Durango fluorapatite, J. Geophys. Res.-Sol. Ea., 105, 2903–2914, https://doi.org/10.1029/1999JB900348, 2000.
Farley, K. A.: (U-Th-Sm)
Farley, K. A., Wolf, R. A., and Silver, L. T.: The effects of long alpha-stopping distances on (U-Th-Sm)
Farley, K. A., Shuster, D. L., Watson, E. B., Wanser, K. H., and Balco, G.: Numerical investigations of apatite 4He/3He thermochronometry: APATITE 4He/3He THERMOCHRONOMETRY, Geochem. Geophy. Geosy., 11, Q10001, https://doi.org/10.1029/2010GC003243, 2010.
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)/He system, Geochim. Cosmochim. Ac., 75, 4515–4530, https://doi.org/10.1016/j.gca.2011.05.020, 2011.
Flowers, R. M.: Exploiting radiation damage control on apatite (U–Th)/He dates in cratonic regions, Earth Planet. Sc. Lett., 277, 148–155, https://doi.org/10.1016/j.epsl.2008.10.005, 2009.
Flowers, R. M. and Farley, K. A.: Apatite 4He/3He and (U-Th)/He Evidence for an Ancient Grand Canyon, Science, 338, 1616–1619, https://doi.org/10.1126/science.1229390, 2012.
Flowers, R. M., Ketcham, R. A., Shuster, D. L., and Farley, K. A.: Apatite (U–Th)/He thermochronometry using a radiation damage accumulation and annealing model, Geochim. Cosmochim. Ac., 73, 2347–2365, https://doi.org/10.1016/j.gca.2009.01.015, 2009.
Flowers, R. M., Ketcham, R. A., Enkelmann, E., Gautheron, C., Reiners, P. W., Metcalf, J. R., Danišík, M., Stockli, D. F., and Brown, R. W.: (U-Th)/He chronology: Part 2. Considerations for evaluating, integrating, and interpreting conventional individual aliquot data, GSA Bull., 132, 137–161, https://doi.org/10.1130/B36268.1, 2023.
Fox, M., McKeon, R. E., and Shuster, D. L.: Incorporating 3-D parent nuclide zonation for apatite 4He/3He thermochronometry: An example from the Appalachian Mountains, Geochem. Geophy. Geosy., 15, 4217–4229, https://doi.org/10.1002/2014GC005464, 2014.
Fox, M., Tripathy-Lang, A., and Shuster, D. L.: Improved spatial resolution of elemental maps through inversion of LA-ICP-MS data, Chem. Geol., 467, 30–41, https://doi.org/10.1016/j.chemgeo.2017.07.001, 2017.
Gallagher, K., Brown, R., and Johnson, C.: Fission track analysis and its applications to geological problems, Ann. Rev. Earth Planet. Sci., 26, 519–572, https://doi.org/10.1146/annurev.earth.26.1.519, 1998.
Gautheron, C., Tassan-Got, L., Barbarand, J., and Pagel, M.: Effect of alpha-damage annealing on apatite (U–Th)/He thermochronology, Chem. Geol., 266, 157–170, https://doi.org/10.1016/j.chemgeo.2009.06.001, 2009.
Gautheron, C., Tassan-Got, L., Ketcham, R. A., and Dobson, K. J.: Accounting for long alpha-particle stopping distances in (U–Th–Sm)/He geochronology: 3D modeling of diffusion, zoning, implantation, and abrasion, Geochim. Cosmochim. Ac., 96, 44–56, https://doi.org/10.1016/j.gca.2012.08.016, 2012.
Glotzbach, C.: Interpreting cooling dates and histories from laser ablation in-situ (U-Th-Sm)/He thermochronometry, Zenodo [code], https://doi.org/10.5281/zenodo.13898183, 2024.
Glotzbach, C., Lang, K. A., Avdievitch, N. N., and Ehlers, T. A.: Increasing the accuracy of (U-Th(-Sm))/He dating with 3D grain modelling, Chem. Geol., 506, 113–125, https://doi.org/10.1016/j.chemgeo.2018.12.032, 2019.
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-Sm)
Guenthner, W. R., Reiners, P. W., Drake, H., and Tillberg, M.: Zircon, titanite, and apatite (U-Th-Sm)
Horne, A. M., van Soest, M. C., Hodges, K. V., Tripathy-Lang, A., and Hourigan, J. K.: Integrated single crystal laser ablation U/Pb and (U–Th)/He dating of detrital accessory minerals – Proof-of-concept studies of titanites and zircons from the Fish Canyon tuff, Geochim. Cosmochim. Ac., 178, 106–123, https://doi.org/10.1016/j.gca.2015.11.044, 2016.
Horne, A. M., van Soest, M. C., and Hodges, K. V.: U/Pb and (U-Th-Sm)
Hourigan, J. K., Reiners, P. W., and Brandon, M. T.: U-Th zonation-dependent alpha-ejection in (U-Th)/He chronometry, Geochim. Cosmochim. Ac., 69, 3349–3365, https://doi.org/10.1016/j.gca.2005.01.024, 2005.
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)/He geochronology: Refinement of the baseline case, Geochim. Cosmochim. Ac., 75, 7779–7791, https://doi.org/10.1016/j.gca.2011.10.011, 2011.
Kirstein, L. A., Foeken, J. P. T., van der Beek, P., Stuart, F. M., and Phillips, R. J.: Cenozoic unroofing history of the Ladakh Batholith, western Himalaya, constrained by thermochronology and numerical modelling, J. Geol. Soc., 166, 667–678, https://doi.org/10.1144/0016-76492008-107, 2009.
Lippolt, H. J., Leitz, M., Wernicke, R. S., and Hagedorn, B.: (Uranium + thorium)/helium dating of apatite: experience with samples from different geochemical environments, Chem. Geol., 112, 179–191, https://doi.org/10.1016/0009-2541(94)90113-9, 1994.
Malusà, M. G. and Fitzgerald, P. G. (Eds.): Fission-track thermochronology and its application to geology, Springer, 393 pp., https://doi.org/10.1007/978-3-319-89421-8, 2019.
Meesters, A. G. C. A., and Dunai, T. J.: Solving the production–diffusion equation for finite diffusion domains of various shapes, Chem. Geol., 186, 333–344, https://doi.org/10.1016/S0009-2541(01)00422-3, 2002.
North, R., White, L. T., Nancarrow, M., Dosseto, A., and Tanner, D.: Sub-Micrometre Resolution FIB-SEM-based ToF-SIMS Used to Map Geochemical Zoning in Four Zircon Reference Materials, Geostand. Geoanal. Res., 47, 125–142, https://doi.org/10.1111/ggr.12463, 2023.
Paton, C., Woodhead, J. D., Hellstrom, J. C., Hergt, J. M., Greig, A., and Maas, R.: Improved laser ablation U‐Pb zircon geochronology through robust downhole fractionation correction, Geochem. Geophys. Geosy., 11, Q0AA06, https://doi.org/10.1029/2009GC002618, 2010.
Pickering, J., Matthews, W., Enkelmann, E., Guest, B., Sykes, C., and Koblinger, B. M.: Laser ablation (U-Th-Sm)
Reiners, P. W.: Zircon (U-Th-Sm)
Reiners, P. W. and Ehlers, T. A.: Low-temperature thermochronology: Techniques, interpretations and applications, Rev. Mineral. Geochem., 58, https://doi.org/10.2138/rmg.2005.58.0, 2005.
Reiners, P. W. and Brandon, M. T.: Using thermochronology to understand orogenic erosion, Annu. Rev. Earth Pl. Sci., 34, 419–466, https://doi.org/10.1146/annurev.earth.34.031405.125202, 2006.
Shuster, D. L. and Farley, K. A.: 4He/3He thermochronometry, Earth Planet. Sc. Lett., 217, 1–17, https://doi.org/10.1016/S0012-821X(03)00595-8, 2004.
Sousa, F. J., Cox, S. E., Rasbury, E. T., Hemming, S. R., Lanzirotti, A., and Newville, M.: U and Th zonation in apatite observed by synchrotron X-ray fluorescence tomography and implications for the (U–Th)/He system, Geochronology, 6, 553–570, https://doi.org/10.5194/gchron-6-553-2024, 2024.
Spiegel, C., Kohn, B., Belton, D., Berner, Z., and Gleadow, A.: Apatite (U–Th–Sm)/He thermochronology of rapidly cooled samples: The effect of He implantation, Earth Planet. Sc. Lett., 285, 105–114, https://doi.org/10.1016/j.epsl.2009.05.045, 2009.
Tripathy-Lang, A., Hodges, K. V., Monteleone, B. D., and van Soest, M. C.: Laser (U-Th)/He thermochronology of detrital zircons as a tool for studying surface processes in modern catchments, J. Geophys. Res.-Earth, 118, 1333–1341. https://doi.org/10.1002/jgrf.20091, 2013.
Vermeesch, P., Seward, D., Latkoczy, C., Wipf, M., Günther, D., and Baur, H.: α-Emitting mineral inclusions in apatite, their effect on (U–Th)/He dates, and how to reduce it, Geochim. Cosmochim. Ac., 71, 1737–1746, https://doi.org/10.1016/j.gca.2006.09.020, 2007.
Vermeesch, P., Sherlock, S. C., Roberts, N. M. W., and Carter, A.: A simple method for in-situ U–Th–He dating, Geochim. Cosmochim. Ac., 79, 140–147, https://doi.org/10.1016/j.gca.2011.11.042, 2012.
Vermeesch, P., Tian, Y., Schwanethal, J., and Buret, Y.: Technical note: In situ U–Th–He dating by 4He/3He laser microprobe analysis, Geochronology, 5, 323–332, https://doi.org/10.5194/gchron-5-323-2023, 2023.
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.
Wolf, R. A., Farley, K. A., and Kass, D. M.: Modeling of the temperature sensitivity of the apatite (U–Th)/He thermochronometer, Chem. Geol., 148, 105–114, https://doi.org/10.1016/S0009-2541(98)00024-2, 1998.
Ziegler, J. F., Ziegler, M. D., and Biersack, J. P.: SRIM – The stopping and range of ions in matter (2010), Nucl. Instrum. Methods B, 268, 1818–1823, https://doi.org/10.1016/j.nimb.2010.02.091, 2010.
Short summary
The (U–Th–Sm) / He dating method helps understand the cooling history of rocks. Synthetic modelling experiments were conducted to explore factors affecting in situ vs. whole-grain (U–Th) / He dates. In situ dates are often 30 % older than whole-grain dates, whereas very rapid cooling makes helium loss negligible, resulting in similar whole-grain and in situ dates. In addition, in situ data can reveal cooling histories even from a single grain by measuring helium distributions.
The (U–Th–Sm) / He dating method helps understand the cooling history of rocks. Synthetic...
