Journal articles
High S and high CO2 contents in haplokimberlite: An experimental and Raman spectroscopic study
Abstract : Sulfur is an important element present in natural kimberlites and along with CO2, S can play a role in the kimberlite degassing. We have investigated experimentally the change in S content and CO2 solubility in synthetic kimberlitic melts in response to a range of pressure (0.5 to 2.0 GPa) and temperature (1500 to 1525 °C). Several initial S concentrations were investigated ranging from 0 to 24000 ppm. The dissolved CO2 and S were determined by Raman spectroscopy and Electron Probe Micro-Analyses. Under the investigated oxidizing conditions (ΔFMQ + 1), S is dissolved in the glass only as S6+ forming sulfate molecular groups (SO42−). The measured S concentration in the glasses increases from 2900 to 22000 ppm. These results suggest that the experimental conditions were below saturation with respect to S and that the S solubility is higher than 22000 ppm for kimberlitic melts; regardless of the experimental conditions considered here. CO2 is dissolved as CO32− molecular groups. The CO2 solubility ranges from 3.0 to 11.3 wt% between 0.5 and 2.0 GPa. CO2 solubility is not affected by the presence of S; which suggests that SO42− and CO32− clusters have two distinct molecular environments not interacting together. This result implies that both CO2 and S are efficiently transported by kimberlitic melt from the upper mantle towards the atmosphere.
https://hal-insu.archives-ouvertes.fr/insu-03092892
Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Monday, January 4, 2021 - 3:15:00 PM
Last modification on : Wednesday, November 24, 2021 - 1:24:02 PM
Long-term archiving on: : Monday, April 5, 2021 - 8:38:39 PM
Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Monday, January 4, 2021 - 3:15:00 PM
Last modification on : Wednesday, November 24, 2021 - 1:24:02 PM
Long-term archiving on: : Monday, April 5, 2021 - 8:38:39 PM
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Morizet et al CO2 and SO2 solu...
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