Neon diffusion kinetics in olivine, pyroxene and feldspar: Retentivity of cosmogenic and nucleogenic neon

Helium diffusion in olivine based on first principles calculations

“…The exceptions are Hart (1984) and Trull and Kurz (1993) who reported very high activation energies of 502 (+133/-113) kJ/mol and 420 ± 20 kJ/mol respectively (Table 3). However, these two activation energies are even higher than recently measured results for neon diffusion in olivine (360-370 kJ/mol in Gourbet et al (2012) and 131 ± 6 kJ/mol in Cherniak et al (2014) although the atomic radius of neon is almost twice of that of the helium.…”

Constraining in situ cosmogenic nuclide paleo-production rates using sequential lava flows during a paleomagnetic field strength low

“…Future similar studies should incorporate less diffusive cosmogenic nuclides that are better preserved to accurately define paleoproduction rates. 21 Ne represents the most studied stable cosmogenic nuclide that is less diffusive than 3 He in olivine and pyroxene from basalt flows (Gourbet et al, 2012). The diffusive loss of Ne is estimated to be less than 1% when using the same temperature conditions (640-740 o C) applied to the He diffusion model and the activation energy and diffusivity constants from Gourbet et al (2012).…”

“…21 Ne represents the most studied stable cosmogenic nuclide that is less diffusive than 3 He in olivine and pyroxene from basalt flows (Gourbet et al, 2012). The diffusive loss of Ne is estimated to be less than 1% when using the same temperature conditions (640-740 o C) applied to the He diffusion model and the activation energy and diffusivity constants from Gourbet et al (2012). An alternative approach would be to reconstruct a cosmogenic depth profile of 3 He in the underlying flow where the shape of the profile would likely deviate from the expected attenuation J o u r n a l P r e -p r o o f profile owing to diffusive loss in a temperature gradient.…”

Comment on “Systematic variations of argon diffusion in feldspars and implications for thermochronometry” by Cassata and Renne

“…Using all the Gourbet et al (2012) Ne data (note: their first two steps were not shown by Cassata and Renne (2013)) and heating schedule, Fig. 1b shows the Ar and Ne Arrhenius plots for a sample having the same domain structure we document for the Madagascar K-feldspar in Fig.…”

“…(b) Shows the same domain distribution modeled to both the Ar and Ne data. Note that the MDD fit describes the two low T data steps fromGourbet et al (2012) while the single diffusion domain model does not.…”