EVERYDAY SCIENCE

Detailed explanation-1: -Downcutting occurs as a river carves out a canyon or valley, cutting down into the earth and eroding away rock. Downcutting happens during flooding.

Detailed explanation-2: -By around 6 million years ago, waters rushing off the Rockies had formed the mighty Colorado River. As the plateau rose, the river cut into it, carving the canyon over time. Smaller rivers eventually cut the side canyons, mesas and buttes that are so characteristic of the canyon today.

Detailed explanation-3: -In most cases no, canyons are not formed by wind erosion.

Detailed explanation-4: -Canyons are created by erosion. Over thousands or millions of years a river’s flowing water erodes, or wears away, soil and rocks to form a valley. The largest and most famous canyons have been cut through dry areas by swift streams fed by rain or melting snow from wetter areas.

Detailed explanation-5: -The three main rock layer sets in the Grand Canyon are grouped based on position and common composition and 1) Metamorphic basement rocks, 2) The Precambrian Grand Canyon Supergroup, and 3) Paleozoic strata.