Research objectives and content
The main objective of this project is to measure the argon solubility and its partition coeffient between crystals and melts during partial melting at high pressures (under upper mantle conditions: 5-25 GPa and 1500-2000 0C). Prior experiments on argon solubility at high pressures have been performed in piston-cylinder-type apparatus (by the Bristol group) and in the diamond anvil cell (Chamorro et al, 1996). Both methodologies present experimental limitations. I propose to carry out new experiments on argon solubility with a multi-anvil apparatus in the Geology Department at the University of Bristol.
Previous results for SiO2 and olivine melts show a linear increase in the argon solubility with pressure at low P (Henry's law), but above 5 GPa the argon solubility drops drastically. No data are avaible for argon solubility in crystals at very high pressure. The results of this project will have important consequences for mantle geochemistry and Earth evolution. Noble gas atoms dissolve in molten silicate with no chemical interaction, so that these data will provide important information on the interstitial structure of melts. The data are also necessary to formulate a complete thermodynamic model of the solubility of gases in magmas. Noble gases are trace elements in magmatic processes which are used as important tracers of mantle evolution. Therefore knowledge of solubility and partition coefficients are essential to constrain models of atmospheric evolution and mantle degassing.
Training content (objective, benefit and expected impact)
This research experience will complete and complement my prior training in the French system (Grandes Ecoles), and will help me firmly establish my research independence, in a different EC country.
Links with industry / industrial relevance (22)