If the present-day multi-km thick icecaps of Mars are nowhere near melting at their base, then why would any earlier ice cap be, especially if it covers only a local area.

All the geological studies of these near-equatorial glaciated areas of Mars agree that the morphology of the deposits is caused by a cold-based glacier and there is no - zero - nil- nitch evidence for ANY melting. No channels, no eskers, no drumlins. NONE of the features that we see at an ice margin on Earth.

Don't speculate about what *might* have happened. Look at the clear and abundant evidence for what *DID* happen.

I agree that it's been interesting that over the past decade the concept of occasional equatorial icesheets on Mars has moved from theoretical possibility to well-proven observation. This is due to better-quality imaging, and persistent investigators determined to look for evidence. Some of their interpretations are a touch optimistic - I think they still underestimate the effect of long slow creep of "soil" on Mars - many of the wrinkles and ridges may have arisen at the top surface of a slowly-moving icy rubble, rather than at the base surface of a slowly-moving glacier. But the difference is fairly subtle in the end.

E pur si muove...