And we have 111ft of that kind of soil here in Iowa. It going to take a hell of a long time to go through that. Its been farmed since the early 1800's. And not all gone, not by far.
I didn't read any further after that, maybe the article does have something to say. But I doubt it.
I will give you the benefit of the doubt and believe that you may be on the top end of the world-wide average, but how does your 80 acres of usable soil help the rest of the world when push comes to shove?
So don't believe me if you like (though I could go dig a hole and take a picture of the black line that separates topsoil from subsoil), but its probably more outrageous to cling to the idea that somehow Iowa is at the top end of a curve that goes from 10 years to 1000 years.
You would have had a whole succession of different types of plants to slowly work the rock surface. Then humans show up, rip out all the trees that kept that hard-won top soil in place, and it all runs off out to sea in no time. Basically it's about places like Iceland, not Iowa, I guess.