Also, what are Paleosols?
Paleosols are nothing more than old soils. The age can vary depending on where they are.
The whole question of dealing with soils is because the global flood is usually placed very close to 2350 BC, and rock formations are almost always very much older. If you want evidence of the flood you need to look at younger deposits, and that would be soils.
For example the channeled scablands of eastern Washington have a great record of the post-glacial floods coming out of Montana. You can track the location and age of the floods pretty well from the soils (both present and absent).
Could these have formed during the Flood 4500 years ago??
Paleosols are in the mind of the beholder and mean nothing.
http://www.answersingenesis.org/tj/v17/i3/paleosols.asp