[728b]

Since the rim of the GC is higher than the source of the river don't forget to make the water run up hill in your experiment to see how much erosion you get.

The above is just an illustration of the fact that your experiment is making a lot of assumptions.

1. That the rock now in the canyon has never been soft. Give me a cake of concrete powder and water and I can erode it in seconds. Give me the concrete after water has been added and it is set and it could take years maybe even hundreds of years to erode.

2. That you know how much water passed by in the making of the canyon. Without knowing the volume of water how can one know the amount of erosion?

All in all your experiment really has little to do with how it was formed or how long it took to form it.

[dangus]

<<The above is just an illustration of the fact that your experiment is making a lot of assumptions. <<

Yes, but those assupmtions are consistent with creationism. The sandstone must have been MADE hard, since it takes a heck of a lot longer than a couple thouand years to turn sand into sandstone. And if the feature was made by the ordinary receeding of water, we actually could guess how much water. Here's a hint: not much. You'd have a few month's worth of erosion, and not at a very fast rate. Actually, one other poster posted the real kicker: Geological upheaval has gone on since the erosion started: The water would have to had run UPHILL early on in the process.