What events or process formed the layers of the grand canyon?

Answer 1

The 13 sedimentary layers of Grand Canyon are the result of 2 billion years of deposits from seas, lakes and marshes, and deserts. The layers formed into rock by enormous heat and pressure from subsequent layers above. The entire region, known as the Colombian Plateau, was then uplifted. The Colorado River, which has remained at just about the same elevation, cut through the layers of rock. Erosion, mostly in the form of water, has widened and shaped the area into it's present form as a canyon.
Grand Canyon is the most spectacular natural place I have ever seen.

Answer 2

The layers were formed by millions of years of deposition on the floor of shallow seas, and were later uplifted. The canyon itself was gradually cut by a river.