[John H K]

THere are very few rocks that are ENTIRELY sulfur.

During the press conference they mentioned they had two remaining hypotheses for the composition of the outcrop (as distinguished from the spheres)....wind blown dust, or volcanic ash.

These are the top planetary scientists in the world, mind you, and they take the volcanism hypothesis quite seriously.

[Fitzcarraldo]

One thing I've noticed is the apparent lack of rock fields outside the crater...maybe this bedrock erodes away in the wind much faster than basalt.

[Hunble]

Oh, perhaps you have confused what I have been saying all along.

Of course all of these rocks and soils are volcanic in origin. The only other alternative would be biological in origin, such as calcium deposits. Now that would get my attention!

Nobody has suggested that the "White Cliffs of Dover" have been discoverd on Mars.

My only argument, is when Earth examples are used which are only found in very close proximity to a volcano. Examples used to explain formations on Mars which are well over 500 miles away from this rover location.

That is like offering the hypothisis that rock layers found in England were formed by volcanoes located in North America. Possible, but there may be a much simpler explanation. Like a meteorite crater only 1 km away?