It puts me in conflict with both. If the Flood eroded one of the mountain ranges, how did it eroded the other two that did not exist at the time?
However, how do you know that formed over millions of years? Mt. St. Helens blew away many preconceived notions about how long it takes many things to form, including feets of layered strata, polystrat trees, canyons, etc. Might it be possible that these mountains formed with overlaps in a much shorter timeframe?
And this is what happens when you shoehorn a fact into your preconceptions. With your preconception, you say that Mt. St. Helens is a mountain. The Appalachians are mountains. Therefore, A can explain B.
A geologist observes that Mt. St. Helens is volcanic. The Appalachians were not formed by volcanoes. Therefore, A does not explain B, as A was formed by a very different process than B.
And why are you assuming that 1 of the mountains was pre-flood and 2 were post flood? Is it possible that all three were preflood? A preflood mountaing may not have been as much rock and may have eroded faster.
"And this is what happens when you shoehorn a fact into your preconceptions. With your preconception, you say that Mt. St. Helens is a mountain. The Appalachians are mountains. Therefore, A can explain B."
No, I didn't say A can explain B. I said A demonstrated C which previously thought to take millions of years could occur in a short time frame. Therefore might it be possible that whatever you are looking at D, that makes you think B is very old, might also have occured much faster.
Understand, I'm not saying anything about Mt. St. Helens directly explains the Appalachians. But if science was so totally and commpletekly wrong, embarrasingly wrong about how quickly some of the things Mt. St. Helens accomplished. Might it be that you are wrong about the appalachians?