>rand Canyon, it was formed primarily by the eroding action of the Colorado River that began about six million years ago
There's that taken from a hat figure, the magic 6 gorrilion, and there is no
snowball chance in hell that small river carved 29 kilometre wide canyon in sand, let alone rock.
No, the GC wasn't a millions of years process with a little water,
it was a day to a few days process of a large amount of water.
That's the only explanation for its scale.
The layers of rock were built quickly, with one layer covering another which had just set, quickly, within hours.
It also accounts for the fossils being concentrated in particular layer levels.
In fact the layers of rock found at the GC can be seen in several places globally, all created by the same huge event.