Anomalous Dome Crater
A type of central dome crater
Anomalous dome craters are 50–250 km diameter complex craters on the icy Galilean satellites. Anomalous dome craters exhibit a relatively bright, large circular dome, surrounded by a ring of rugged massifs. Surrounding this central complex is an annulus of smoothed or mottled material, the outer boundary of which is sometimes marked by a discontinuous circular lineament (Schenk 1996).
Coherent rim structures are absent. They have a broad, low rise (Neith, Ganymede) (Fig. 1), incomplete outward or inward facing scarp segments (Doh, Callisto) (Fig. 2) or no observable rim (Anzu, Ganymede).
The dome-to-rim diameter ratio is roughly constant (0.4), regardless of crater size.
Anomalous dome craters are not associated with bright ray or floor deposits which suggests that they formed after bright materials were emplaced on Ganymede.
The lack of identifiable rim suggests a negligible crater depth (Schenk et al. 2004, p. 430).
Ejecta and secondary craters are recognized beyond their outer boundary, confirming an impact origin (central dome craters).
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