Tectonic pit chains are geologic landforms observed on many solar system bodies, and in the outer solar system they are most clearly observed on Enceladus. Pit chains form above a dilational fault or extensional crack underlaying a layer of loose, unconsolidated material (hereafter referred to as regolith). Using an updated map of pit chains, we identify individual pits that we use to measure the thickness of the regolith they form in. We measured regolith thicknesses up to 700 m (mean=250 m, n=116), and constrained the time needed to deposit the observed sequences of regolith using recent models of plume-generated regolith deposition. We interpret the long deposition times needed to match regolith thicknesses to suggest that Enceladus’s mass flux from the plume was significantly higher in the past, that the regolith is possibly a low-density/high-porosity material, and/or additional regolith-forming processes (like alternative vent localities) exist, or have existed.

Speaker: Emily Martin (Smithsonian National Air and Space Museum)

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