Physics
Scientific paper
Jun 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994e%26psl.124..161h&link_type=abstract
Earth and Planetary Science Letters (ISSN 0012-821X), vol. 124, no. 1, p. 161-167
Physics
75
Argon Isotopes, Diffusion, Geochemistry, Geochronology, Muscovite, Crystal Structure, Grain Size, Radioactive Age Determination
Scientific paper
The temperature-time significance of Ar-40/Ar-39 muscovite ages is difficult to evaluate quantitatively because of ambiguities in the choice of an appropriate model diffusion geometry, the effective diffusion dimension and large uncertainties in experimentally determined diffusion parameters. Laser Ar-40/Ar-39 studies of natural Ar-40 concentration gradients suggest that argon loss in muscovite occurs primarily via cylindrical volume diffusion, commonly with an effective diffusion dimension equal to the crystal diameter. The present study tests the cylinder model geometry and the control of physical grain size on the effective diffusion dimension by measuring the anisotropy of a natural Ar-40 diffusion gradient, parallel and perpendicular to 001, in a single euhedral muscovite phenocryst. The new data, combined with previous studies, clearly indicate loss of Ar-40 via cylindrical volume diffusion and strongly suggest that loss of Ar-40 across the 001 sheets (slab diffusion geometry) is minimal in undeformed crystals.
Bowring Samuel A.
Hames Willis E.
No associations
LandOfFree
An empirical evaluation of the argon diffusion geometry in muscovite does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with An empirical evaluation of the argon diffusion geometry in muscovite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An empirical evaluation of the argon diffusion geometry in muscovite will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1864842