Describe the processes that likely led to the formation of the rock and the canyon wall?

The specific geologic processes and timing that formed the Grand Canyon spark lively debates by geologists. The general scientific consensus, updated at a 2010 conference, holds that the Colorado River carved the Grand Canyon beginning 5 million to 6 million years ago.

It was most likely weathering and erosion. The grand canyon was originally a large river! This river most likely wore away and dragged off particles from the (to be formed) canyon. over time, these processes would certainly be able to form a structure like the grand canyon.