Question

Formation of grand canyon in South western United States is an example

Answer 1

The terraced walls of the canyon were created by differential erosion and this is an example of differential erosion.

During 100,000 and 3 million years past, volcanic activity deposited erupted ash and lava over the area which at that age were completely blocking the flow  of  the rivers.

These volcanic rocks are most recent creation of Earth in in the canyon.The specific process of geological phenomena  and timing that formed the Grand Canyon a subject of  debates by geologists.

The general scientific consensus, updated at a 2010 conference, holds that the Colorado River carved the Grand Canyon in the beginning 5 million to 6 million years ago.