This an interesting discussion. A while back I started a thread about the geology of the 'Inca village formation." I was curious what sort of exotic geology could create such an interesting formation.

To my suprise...there were at least three very sound theories - all so good they are competing against each other. All have examples found on Earth. Two could be re-created using plaster of paris sand and water in my own back yard.

So the number of anomalies found on Mars points to a lack of knowledge in geology by the observer rather than evidence they are artifical.

MG