Atmospheric geology

Volatile cycling and magma degassing on Earth and Exoplanets: A window into the geodynamics of planetary bodies

PI: Prof. Luca Caricchi and Prof. Nicolas Greber

Collaborators: Prof. David Ehrenreich and Prof. Johanna Marin-Carbonne (UNIL)

Funding: SNSF grant N° 200021_215095

Description: 
The evolution of the Earth’s atmosphere has been shaped by magmatic degassing. In turn, the chemistry of magmatic gases is linked to the conditions of magma formation and therefore to geodynamic. Thus, linking the chemical evolution of the atmosphere to Earth’s geodynamic evolution would allow the study of exoplanets’ geology from the investigation of the chemistry of their atmospheres.  
To achieve this target, we will measure the content of H2O, CO2, S, Cl and F as well as the oxidation state of S, in apatite inclusions in zircons with age spanning the entire geological history of our planet. Zircons serve both to date the apatites precisely and to avoid any chemical exchange with the exterior. These data will allow to establish which ratios of volatiles species in exoplanetary atmospheres can indicate if a magma ocean operated on the planet or if active plate tectonics is plausible. 

Positions:

• One PhD (Lili Loth): Geochemistry of apatite inclusions in zircon across the Great Oxidation event
• One Postdoc (Mathilde Kervazo) Numerical simulation of planetary dynamics. The researcher will be co-supervised by Prof. David Enrenreich. The innovative part of her/his work on the project will be the integration of planetary dynamic models and the calculation of the evolution of their atmospheres over time
• One Postdoc (Clementine Antoine): Geochemistry of apatite inclusions in zircons in the Hadean and Archean