[okie01]

"Yup. I've read that (the) Ukraine has a topsoil depth of 150 feet. It blew in there over the eons from other places."

Such wind-deposited soils are called loess. There are sites in my home county in Oklahoma where the topsoil is 30-40' deep.

[blam]

"There are sites in my home county in Oklahoma where the topsoil is 30-40' deep."

That's good, huh? Good farming soil.