Need help with identification

[Kshields]

Found near Lake Huron Ontario. I can see the symmetry and the darker pieces on top and that they coincide with the curved spacing below. Hard to see in pics but I’ll do my best to show. I pointed out the two less obvious in the possibility it help in identifying due to the structure etc. The other is the lighter grey square that is more obvious and visible. Thank you 

 

[Kane]

Possibly an artifact of non-biologic geologic processes as opposed to a fossil. Finding vertebrate fossils around lake Huron is not likely, save for Pleistocene erratics and Devonian placoderms. If you could narrow this down to county level, I could probably tell you more about the bedrock's geologic age.

[Kshields]

1 minute ago, Kane said:

Possibly an artifact of non-biologic geologic processes as opposed to a fossil. Finding vertebrate fossils around lake Huron is not likely, save for Pleistocene erratics and Devonian placoderms. If you could narrow this down to county level, I could probably tell you more about the bedrock's geologic age.

I found it just down from the main beach of Grand Bend ont 

[Kane]

The rocks there are mostly Mid-Devonian in age, Hamilton Group. That being said, slightly older limestones and dolostones do occasionally wash up there.