1 Planetary volatiles

 1.1)         Apatite is the “star” mineral in planetary volatile study, since it is the only volatile-bearing mineral in both lunar samples and differentiated planetary materials. We have studied the petrogenesis of apatite from Chang’E-5 samples and its volatile characteristics. Through both experimental simulation and theoretical modelling, we have developed a new apatite hygrometry based on the volatile evolutional trend in lunar apatite. The ultimate goal is to gain better constraints on the volatile budget of the Moon from the apatite perspective.

1.2)         Both orbital observations and Martian meteorites indicate an enrichment of both chlorine and sulfur in Mars. Mounting evidence suggests the presence of ocean in the Martian history. How to decipher the volatile records in Martian meteorites will be the focus of our experimental studies.

1.3)         The origin of H₂O in Earth has been debated. Enstatite chondrite has been one of the strongest candidates as the building blocks for Earth, as suggested by its similar isotopic compositions to Earth. Was the Earth H₂O sourced from enstatite chondrite as well, and how?

2 The cycle of volatiles, trace elements and redox budget in Deep Earth

My previous work covered research topics such as the role of slab melting in mass transfer in subduction zones, the role of apatite in halogen deep recycling; volatile and trace element partitioning between apatite and melt; sulfur solubility in hydrous slab melt and its contribution to sulfur cycle, etc. The next phase research will focus on the redox/oxygen cycle and the relationship between redox and volatile cycles.

3 Redox evolutions of Earth and neighboring planets

The inner solar system planets all started as being reduced which allowed the formation of a metal core. However, these planets display a large range of redox states, with mercury being the most reduced (as low as IW-7), and Earth being the most oxidized (up to HM). What is the cause for such a divergence in the redox evolution path for these planets? Different mechanisms have been proposed. The most prominent theory invokes high pressure redox equilibria in either the lower mantle or a magma ocean. Our interests lie in the role of volatiles during the redox evolution of these planets. For example, the solubility, partitioning and precipitation of volatiles are governed by oxygen fugacity. In turn, these volatiles can take part in redox exchange causing oxygen fugacity variations.