Evidence for xenon silicates at high pressure and temperature | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  Evidence for xenon silicates at high pressure and temperature

Type de publication:

Journal Article

Source:

Geophysical Research Letters, Volume 29, Ticket 18, p.1883 ; doi:10.1029/2002GL014973, 2002 (2002)

ISBN:

0094-8276

URL:

http://www.agu.org/pubs/crossref/2002.../2002GL014973.shtml>/

Mots-clés:

Physico-chimie des fluides géologiques, UMR 7154

Résumé:

We present evidence for the stability of xenon silicate phases at deep crustal conditions. High pressure-temperature investigations of the Xe-SiO2 system were conducted using diamond-anvil cells combined with laser heating and external resistive heating. A new compound was synthesized at 0.7–1.5 GPa and 1500–1750° as evidenced by Raman spectroscopy. Upon temperature quenching, the material undergoes a back transformation to another Xe-SiO2 phase stable up to 2.14 GPa. X-ray diffraction data show that this second phase has a cubic structure [a = 8.03(±0.03) Å] and a bulk modulus of 20(±0.6) GPa. The phase was found to have a minimum of 4 wt% Xe from electron microprobe analysis. These results indicate that the chemical affinity of Xe and silica increases at high pressures and temperatures. Hence Xe can be potentially hosted by silicates in the crust, which helps to resolve the geochemical paradox of the ‘missing Xe’ in the atmospheres of the Earth and Mars.

Notes:

GRLChrystèle SanloupGeophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, Washington, D.C., USARussell J. HemleyGeophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, Washington, D.C., USAHo-kwang MaoGeophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, Washington, D.C., USA