LJ said:

>So water seems to have been almost everywhere on Mars... hopefully
>Spirit can make it to Bonneville and check out some strata.

The "Humphrey" rock observed by MER-A is believed to be an igneous
rock (It looks quite glassy). The vugs observed in Humphrey are consistent
with the water (steam actually) from magma.

Ths sulfate salts discovered by MER-B were probably created underground and could be over three billion years old (Mars was different world then). Steve Squyres has been very careful not to theorize about the actual age of the sulfate deposits. Also he has never claimed that the sulfate deposits formed on the surface of Mars although he's kept that option open. The "water" that created these sulfate deposits was probably sulfuric acid. If you take pure water and blow sulfur dioxide gas through it then you get sulfuric acid. Sulfur dioxide gas comes from volcanic vents. The data from Humphrey shows water of magma (liquid rock). With both MERs, we've observed water but it's ground water with a magma association. Now life can exist in that sort of environment. For example within the geysers in Yellowstone National Park there's archea living in high temperature ground water metabolizing the sulfur. The possibility that life existed in the Martian sulfates can best be determined by examining sulfur isotopes (something that MER can not do). Also I'm of the opinion that White Mars might be consistent with this data. Nick's theory allowed for water ice to be transported by liquid carbon dioxide. If this water ice encountered a volcanic vent then these sulfate deposits might be the consequence. However I'm not a geologist. We'll have to wait and see if Nick can reconstruct his theory to explain this new data.

Gary