Interesting. One thing they dont' mention in this Ron, is why they are shaped that way. Why not dunes like we have.They are called prairie mounds, pimple mounds, or mina mounds. Thet are low naturally occurring hillocks, randomly distributed over level terrain.
You will find more detail on these mounds on the link below.
Prairie Mounds?
In this article, we discuss a geological feature that is often mistaken for an archeological feature: the prairie mound.archeology.uark.edu
Bob, your getting too geologicalific for me. But, I did find this.nteresting. One thing they dont' mention in this Ron, is why they are shaped that way. Why not dunes like we have.
They are called prairie mounds, pimple mounds, or mina mounds. Thet are low naturally occurring hillocks, randomly distributed over level terrain.
You will find more detail on these mounds on the link below.
Prairie Mounds?
In this article, we discuss a geological feature that is often mistaken for an archeological feature: the prairie mound.archeology.uark.edu
Another interesting and maybe even compelling hypothesis is that they were formed by gophers. Yes, gophers.
A number of sensible, thought-provoking hypotheses. I admit I'm a sucker for fluvial explanations.