Was the mantle a driver of the "Great Unconformity?"
The deep Earth origin of the Great Unconformity:
The deep Earth origin of the Great Unconformity (nature.com)
A review:
https://arstechnica.com/science/2026/11/earths-churning-mantle-may-have-created-the-great-unconformity/
Interesting theory. Could explain some other things that make the North American Plate somewhat different.