Figure 8
(A) Sketch showing a perspective cross-sectional view of Mercury’s cratered terrains undergoing structurally controlled upper crustal devolatilization and collapse. The yellow arrows trace volatile escape routes in extensive fault systems. We note the presence of an upper zone, consisting largely of lags, generated during the devolatilization The trapping of some of the volatiles beneath impact crater interior plains could have set the conditions for the later regional hollow development. (B) Chaotic terrain landscape following the large-scale volatile losses from the upper crust. The illustration shows how the structurally controlled collapse produced breached rims and aligned knobs observed throughout the ancient crater rims and intercrater regions, as well as aligned hollows within the crater’s interior plains.
