In this project we have developed new high precision isotopic systems that we applied to terrestrial and extra-terrestrial samples. Isotopic ratios record the signature of specific physical processes and via the measurements in natural samples they can be used to decipher the history of the natural samples and the relation to the history of their parent bodies (e.g. Mars, the Moon).
Along the course of this project we have developed the first high precision isotopic measurements of gallium, rubidium, zirconium , tin , platinum and palladium as well as improved and obtained new results on zinc, copper , silicon, calcium, chromium, iron, potassium and titanium isotopes in lunar and a multitude of meteoritic samples.
We discovered that Ga and Rb are isotopically different between bulk meteorites and bulk silicate Earth, suggesting that the terrestrial Ga and Rb have not been inherited from the late arrival of meteoritic material after its formation but reflect an isotopic fractionation processes such as core formation or volatilisation-this is a major result in order to tackle the issue of the origin of volatile elements. By using Zn, and Cr isotopes we have found that volatile elements are re-distributed during the magma ocean phase of the Moon and that the Moon may actually be even more volatile depleted than previously thought suggesting the Moon is water poor. We have also worked on the most volatile rich Moon rock, the so-called rusty rock, and found that this sample is the isotopically lightest sample ever measured in the solar system and suggest that the origin of volatiles in this rock (including water) must be due to secondary condensation and it is not primordial. We also show that the isotopes of elements with affinity with iron (siderophile elements) that partitioned into the Earth's core, can be used to trace the origin of subduction on Earth, which is linked to the origin of plate tectonics.
In summary, through the combination of various isotopic measurements we demonstrated that the chemical composition of terrestrial planets is the consequence of volatility processes during and after the accretion of planets and planet embryos. This is a change in our understanding of planet formation, as it is opposite to previous dominating idea that the composition was inherited from more ancien nebular processes.
We have published over 60 peer-reviewed papers in high-impact journals (e.g. PNAS, Science Advances, Nature Astronomy, Earth and Planetary Science Letters...) as well as provided oral presentation in multiple international conferences, such as the Goldschmidt conferences or the American Geophysical Union.
