Here's how it works:

* Weathering: This is the process of breaking down rocks and other materials at the Earth's surface.

* Mechanical weathering: This involves physical forces like freezing/thawing of water in cracks, abrasion from wind and water, and the effects of plant roots.

* Chemical weathering: This involves chemical reactions like the dissolving of rock by acidic rainwater or the oxidation of iron in rocks.

* Erosion: This is the process of transporting weathered material away from its original location. Wind, water, and ice are all agents of erosion.

Canyons are formed when:

1. Weathering breaks down rock: This creates loose material that is easier to erode.

2. Erosion carves the landscape: Water, often flowing in rivers, cuts into the weathered rock, gradually carving out a deep, narrow valley with steep sides.

The Grand Canyon, for example, is a prime example of how weathering and erosion have shaped the landscape.

So, while weathering is not the only factor in canyon formation, it's a crucial first step.