Flake utilization question-see pics

[autographcollector11]

Does anyone have an idea what type of work would cause the utilization marks on this large flake? It looks like it's been scraped but on what?

 

[reuellis]

Percussion bulb through a less than ideal part of the flint/chert?

 

[rock]

Ill play, waste flake the lines are cortex. Lets see some of your whole finds?

 

[Mark Todd]

I have a white rock driveway, that has lots of examples like you post. Hope it's just a coincidence but I doubt it. I also hunt a few fields that are full of glacial chert like what you regularly post. I'm In Illinois also, happy hunting.