150 years ago, Hugh Miller (Geologist, lay preacher - and yes technically Creationst) observed that there was "a cycle of nonsense". That most absurd ideas weren't new, just older discredited ideas returning.
Relevence?: at the time self identified Scriptural Geologists claimed that the canyon downstream of Niagra Falls would have been cut in only a few thousand years (Yeah foolish argument, but it was 150 years ago, people were dumb then). And as Miller pointed out, you have to look at how long the rock formations the canyon was being cut through would have taken to form to get anything like an estimate of mininum earth age.
I don't have a direct quote or reference handy but. I saw a program on either History or Discovery a few months back & they were explaining that the bulk of the canyon (through the es's part) could have been cut in an amazingly short time. Something like 10 years or less? Once a section of the hard rock gave way, the water ripped through a very long section of the soft sediment behind it until it got back to a straighter channel & erosion slowed down to a more normal pace.
I didn't take notes at the time to get my quotes accurate but I remember saying to myself, "WOW, that would have been a tourist attraction"!