Answer:
Ancient Precambrian rocks, exposed only in the deepest canyons, make up the basement of the Colorado Plateau. ... These rocks formed deep beneath the surface of the earth and were uplifted, eroded, and exposed for eons. By 600 million years ago North America had been eroded to a remarkably smooth surface.
Explanation:
I searched it on the internet and this is what i got so you have to use your own words. You definately don't wanna plagerise. But here is what i found for you. Now you only have to put it into your own words.
