Solubility and trapping of helium in apatite

Peter K. Zeitler, Eva Enkelmann, Jay B. Thomas, E. Bruce Watson, Leonard D. Ancuta, Bruce D. Idleman

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

A fundamental but unquantified assumption in U-Th/He dating of apatite is that grains do not incorporate extraneous helium by solution or other processes, but large age dispersion seen in some samples suggests that this assumption might be violated. Our laboratory experiments show that helium solubility in apatite is quite low and unlikely to lead to age dispersion in most samples. However, in some samples highly variable and sometimes large helium uptake suggests that apatite grains can trap helium in microvoids that could be derived from fluid inclusions or other microstructures, a conclusion supported by crushing and step-heating experiments. The presence of such microvoids raises the possibility that closure and age systematics could be complicated either by trapping of internally generated radiogenic helium and/or alteration of helium diffusion kinetics by impeding diffusion.

Original languageEnglish (US)
Pages (from-to)1-8
Number of pages8
JournalGeochimica et Cosmochimica Acta
Volume209
DOIs
StatePublished - Jul 15 2017

Keywords

  • Apatite
  • Diffusion
  • Helium
  • Solubility
  • Thermochronology

ASJC Scopus subject areas

  • Geochemistry and Petrology

Fingerprint Dive into the research topics of 'Solubility and trapping of helium in apatite'. Together they form a unique fingerprint.

  • Cite this

    Zeitler, P. K., Enkelmann, E., Thomas, J. B., Watson, E. B., Ancuta, L. D., & Idleman, B. D. (2017). Solubility and trapping of helium in apatite. Geochimica et Cosmochimica Acta, 209, 1-8. https://doi.org/10.1016/j.gca.2017.03.041