Yes, my statement didn't have enough impact.
Here in japan there are rock formations that we find hidden in the forest that could easily be 500-1000 years old!
@Sshredder: I have placed a lot of stone on trails over the last 3 decades. I built a patio last year and working on garden walls this year. I can appreciate the builders choice of rock, its placement, and how long it will last if done right. Do it wrong and people will ride around it and that just drives me crazy. (short drive)