Remember, this is not Earth. Mars does not have techtonic plates or rapid erosion.
If a large volcano close to the Opportunity landing site is discovered, which has eroded away, then that would be a major scientific discovery.
Apologies, had a friend come over to visit and missed the posts where people wanted to find out about the sulfur.
During today's press conference, archived on Real Media on the cspan site (look in the "latest video" column for the link:
http://www.cspan.org/ Can't remember how many minutes in, but Steve Squires stated that right before the conference started they'd just gotten the first spectral data from the outcrop and it was full of sulfur, they were still analyzing the data.
