> Among volcanologists, "table mountain" is a term applied to a specific type of landform that is produced by subglacial eruptions:

No, sorry, it isn't. You are referencing websites and reports that are using loose translations rather than specific geologic terminology.

If you had said "Tuya" from the start, I wouldn't have argued. there is only one type of Tuya. There are MANY types of "table mountain". It is a non-generic term which simply describes morphology.

> To confirm they are table mountains there are certain spectrographic signatures you could look for, such as for example hematite expected in a hydrothermal environment. And also the volcanic rock rhyalite.

Haematite, as in Haemoglobin (but most Americans can't spell Greek words, so I'll let you off this one)

Rhyolite - no excuse. If you want to be a parrot, at least get the words right.

And in any case you are wrong. The vast majority of tuyas are basaltic in composition, and the diagnostic rock assemblage is hyaloclasite - a disintegrated mixture of fragmented glassy shards, crystals, and clays diagnostic of explosive eruption in an aqueous environment. Mary Chapman has some good publications in this field.

Just to twist the bayonet, there are no reliable reports of hyaloclasite on Mars. None of the mineral assemblages are aqueous enough to fit.

But let's sheath the swords and wait until the MER 2003 mission to Melas Chasma. That should bring some ground truth into our wildly unconstrained debate.

Bob Clark