Scraper or Knife?

[autographcollector11]

Found in Illinois near a local river. In looking at the edgework-would this be a knife or a scraper? Also-is this type of edgework more common in some eras than others?

Is there any way that the flaking could be due to natural forces such as freeze thaw, foot traffic or tumble in water? Seems to be too consistent to be natural.

Thoughts?

 

[rock]

We call them flakers here. Its a large reduction flake turned to a tool. With just edge work it would be very hard to say what age it is. Nice piece