entrenched river meander
Green River entrenched meander in Canyonlands National Park, Utah.

NPS photo by Neal Herbert.

[Site under development]


Weathering and erosion are geologic processes that shape Earth’s landforms over vast periods of time through the actions of water, wind, ice, and gravity.

  • If a particle is loosened, chemically or mechanically, but stays in place, it's called weathering.
  • Once the particle is moved by flowing ice, water, or wind, it's called erosion.

Sediment is the name for loose, uncemented pieces of rock or minerals. Sediments are classified by size—from large to small—boulders > cobbles > pebbles > sand > silt > clay.

All of that eroded material has to go somewhere. When an accumulation of eroded sediment falls out of the flow, it is called deposition.

Last updated: September 12, 2019