posted on Aug, 25 2012 @ 12:22 PM
If there was wind and/or water erosion on that area I would expect to see some effect of that erosion on the rocks instead of those sharp edges, so I
think only minimal erosion has happened there.
One thing I have noticed in the photos taken by the Mars rovers is that different coloured dust has different densities, so some colours (blueish) are
more easily moved by wind than others (reddish), so the difference in colour may give an idea of more erosion than there really is.
And no, I don't think it's a "pillar holding up a rock". look at the following animation to get a better idea of the scene.
(the images are not from that photo, but they show the same rocks)
According to AlgorimancerPG, that longish rock is some 28 cm long and is at a distance of 5 metres from the camera.