Isotope tracers of volatile depletion in the solar system – ISOVOL

Most planetary materials including meteorites and planets show evidence for volatile depletion, meaning the most volatile species in the solid bodies of the solar system are depleted relative to the solar composition as defined by the solar photosphere. The extent of these depletions are unique to each body. The objectives of this project are to develop new isotope tracers for the conditions and timing of volatile element depletion in the early solar system in order to better understand the processes that lead to volatile depletion. We will first use high precision isotope measurements of Sr isotopes using thermal ionization mass spectrometry to define more precisely when volatile depletion took place in calcium aluminium rich inclusions, in chondrules, in ordinary chondrites and in differentiated meteorites. This will help us distinguish between various mechanisms of volatile depletion.
Second, we will develop the isotope cosmochemistry of Rb and Sb that are both volatile elements with condensation temperature of 800 K and 979 K respectively. This will help us determine whether partial condensation, partial evaporation or another mechanism explain the depletion in volatile elements. Rb isotopes will be particularly useful to study chondrites and achondrites, and possibly chondrules, while Sb will be particularly useful to investigate iron meteorites that are volatile depleted. These observations will then be integrated with astrophysical models for the protoplanetary disks.