20-EPN-034: Calibration of the Al-in-olivine thermometer: Insight into the thermal history of type II chondrules
Visit by Thomas van Gerve and Kat Shepherd, KU Leuven (Belgium) to TA2.9 Ion Probe Facility (IPF), CRPG (France).
Dates of visit: 18-22 October 2021
Report Summary: Chondrites are the most primitive agglomerates formed in the solar system. In this project, we want to develop a thermometer based on Al-in-olivine/spinel equilibrium to calculate the temperature of formation of chondrites. or this project, we have performed a large number of new low- to high-pressure (1 atm – 10 GPa) experiments relevant to chondrule formation at the KU Leuven.
Experiments were run at high temperature (1200-1800°C), under variable oxygen fugacity conditions (IW+1 to IW+5, IW = iron-wustite). From 18-22 October 2021, Thomas van Gerve and Kat Shepherd (KU Leuven) worked with the Cameca IMS 1270 E7 ion probe at CRPG, Nancy, under the supervision of Dr. Johan Villeneuve and M. Nordine Bouden. We have measured the following masses: 12C, 16O1H, 18O, 19F, 27Al, 30Si, 32S and 35Cl in olivine, glass and glass inclusions. During our analytical session, we measured ~ 150 points in olivine and glass in addition to the standards. Results are extremely reproducible and show a trend of slightly increasing Al content in olivine as a function of the Fo content (molar Mg/(Mg+Fe)) of olivine. Using our new SIMS results, we are in the process of developing a thermodynamically rooted model taking into account major components in spinel and olivine.
Read the full scientific report, with kind permision by Thoma van Gerve and Kat Shepherd.