if the Grand Canyon was created by water erosion from the Colorado river, then how come there isn’t grand Grand Canyons around all or most major rivers?

Question

if the Grand Canyon was created by water erosion from the Colorado river, then how come there isn’t grand Grand Canyons around all or most major rivers?

In: Earth Science

Answer 1

They do, sort of. But the depth of canyons depends on a few things.

To make really deep canyons, you need soft stone that erodes easily (Grand Canyon is lots of loose sandstoney stuff), with a river that flows pretty constantly, in a very geologically stable area. The Grand Canyon area has looked pretty similar for millions on millions of years, giving the river a lot of time to cut a deep canyon.

In many places one or all of these are missing. If the stone’s really hard, the water doesn’t cut well. If the local climate changes a lot, the river can dry up. If the geology shifts, the rive can change it’s course.

And in many places rivers deposit more soil than they remove, regularly flooding their banks and depositing silt that builds up the land rather than cut it.