Smooth plains on Mercury
Patches of small smooth plains cover a substantial portion of the Mercurian surface, but their origin and relation to the global evolution are not completely understood. We update the global inventory of small smooth plains on Mercury, classifying their spatial distribution, absolute model ages, and possible origins. We reveal that both large and small smooth plains on Mercury were dominantly emplaced within ∼200 million years around 3.7 Ga. Peaked formation of large impact basins may be a major trigger for this short-term and global-wide volcanism.
High-magnesium terranes on Mercury
Various geochemical terranes are identified on Mercury based on their Mg/Si and Al/Si values, providing insights to the structure and temporal variations of the poorly-constrained mantle compositions. The high-magnesium region (HMR) on Mercury contains end-members in terms of both color and geochemistry. Using impact craters as probes, we reveal a uniform crustal structure across the entire HMR and demonstrate that mantle materials beneath HMR feature high-magnesium. HMR was derived from multiple mantle sources, possible over an ancient impact basin. The high-reflectance red plain in Rachamninoff, formed by volcanism at ~1.7 Ga, also features high Mg and low Al. The results show compositional zoning in the mantle and the existence of prolonged local thermal anomalies, so both source and degree of partial melting were varied.
Impact crater statistics and model age
Crater statistics and size-frequency distribution are the major way to study relative and absolute model ages for planetary surfaces. However, people should be aware of the limitations in both the theoretical background and practical applications of this technique. I am committed to improving the accuracy and reliability of crater statistics.
Hollows and volatiles on Mercury
Surprisingly, the surface of Mercury turns out to be volatile rich, and the loss of volatiles have formed the mysterious hollows. I am interested in the volatile compositions, the formation mechanism of hollows and other geological processes related to subsurface volatile activities on Mercury.