[P-PS04] Mercury Science and Exploration

[PPS04-08] Effusive Volcanism and Volatile-Rich Layer Interactions on Mercury: Implications for Chaotic Terrain Formation

★Invited Papers

*Chloe A Marini¹, Alexis P. Rodriguez², Deborah Domingue³ (1.University of Alabama in Huntsville, United States, 2.Marshall Space Flight Center Redstone Arsenal, United States, 3.Planetary Science Institute, United States)

Keywords:Mercury, volcanism, chaotic terrain, volatiles, maar

Extensive effusive volcanism on Mercury emplaced vast lava flows, forming the planet’s northern plains. Recent analyses demonstrate that these plains border several of Mercury’s largest chaotic terrains, suggesting significant interactions between volatile-rich upper crustal materials and magmatic processes. Morphological observations indicate characteristics consistent with maar-like explosive eruptions, analogous to terrestrial events in which ascending magma superheats subsurface volatiles, triggering explosive venting. On Mercury, this process likely involved multiple volatile species, including halite (NaCl), water (H₂O), and elemental octasulfur (S₈).
Furthermore, partial melting of the volatile-enriched layer may have driven episodic, high-volume outflows that incised channels and reshaped the landscape. The resulting mechanical weakening of the upper crust likely promoted the collapse of overlying strata, accelerating chaotic terrain formation. The absence of terminal deposits supports the hypothesis that the liberated volatiles were inherently unstable and underwent rapid sublimation following emplacement.