However..
...we're not talking about Earth conditions here, are we?
The word "melting", in the thin Martian atmosphere, would not apply
to post-impact events in those martian craters; sublimation or flash-freezing, yes.
Hey! That's one of Nick's paradigms: "Earth is not an analogue for Mars."
My feeling is, until the gravitometric or in situ core-sampling data
comes in, refrain from subjective commentary. Sit tight!~We got a long wait
for such data to come in.