Opportunity microscopic views of rock outcrop (pics)
Are the spheroids that seem to be embedded in the layers the same things as are found scattered on the soil?
The rock sure looks like something that was formed in water (see below), but of course looks can be deceiving. What other processes could produce this kind of rounded, flowing structures?
And what would you give to be there with a rock hammer and a geochem lab?
(from this site)