Floor-Fractured Craters on Ceres and Implications for Interior Processes

Several of the impact craters on Ceres have sets of fractures on their floors. These fractures appear similar to those found within a class of lunar craters referred to as “Floor-Fractured Craters” (FFCs). We have cataloged the Ceres FFCs according to the classification scheme designed for the Moon. An analysis of the depth to diameter ratio for Ceres craters shows that, like lunar FFCs, the Ceres FFCs are anomalously shallow. Large (>50 km) Ceres FFCs are most consistent with Class 1 lunar FFCs, while smaller craters on Ceres are more consistent with Class 4 lunar FFCs. This suggests that Ceres FFCs may similarly be undergoing fracturing due to the intrusion of a low-density material below the craters. While on the Moon (and Mars) the intrusive material is hypothesized to be silicate magma, cryomagmatic intrusions are more likely responsible for the formation of the Ceres FFCs. However, new models suggest that at least some of the FFC fractures may have formed due to the solid state flow of a low-viscosity, low-density material into the crater wall.