Amenthes Crater

The floor of a 75 km diameter crater in the Amenthes region of Mars displays lobate flow features in the center of this THEMIS image. It is possible that the flows are lava but there is no sign of the source vent. Note how the material has spread out across the floor of the crater and surrounds a peninsula of higher terrain in the lower 1/3 of the image. Wherever the flow encounters elevated topography it fails to lap up onto it and instead produces a distinct margin that in some places looks thicker than the rest of the flow. These are the features of a viscous material like lava but a dense mudflow could also produce such features. Viking and MOC wide angle images of this crater show a stubby channel entering from the southern rim, with the east side just visible in the bottom left of the THEMIS image. It is possible that a mud flow could have emerged from this channel, perhaps even multiple times, to produce the features we see today.