Lessons · Teaching · weathering, erosion and deposition
Three words for three different jobs
Weathering breaks rock down where it stands. Erosion carries the pieces away. Deposition drops them somewhere else. They happen in that order and they are not synonyms, which is exactly what an examination checks.
Hone is a place to practise a career, one idea a day. This is one of its lessons, written out in full and free to read without an account.
In beta. This lesson was written for Hone and has not yet been checked by a state certification officer. Practice material, not professional advice. What that means.
What it is for
A river valley, a beach and a cave are all the same three processes with different agents, and a pupil who has the three words can explain any landscape they are shown rather than memorising a list of landforms.
How to think about it
For any landform, ask three questions in order: what broke it, what moved it, and where did it stop? Name the agent for each: water, ice, wind, gravity, or a living thing. Note that weathering does no carrying at all.
Worked example
Weathering: freeze and thaw splits rock, roots prise it, chemicals dissolve itAll of it in place. Nothing has moved yet.
Erosion: water, ice, wind or gravity carries the loose pieces awayThe moving stage, and the one that needs an agent.
Deposition: the carrier slows down and drops its loadWhich is why a river deposits on the inside of a bend, where it is slowest.
A beach is deposition; a cliff is erosion; a crack widening in winter is weatheringThree words, three jobs, one coastline.
Your turn
Name the process that breaks rock down without moving it.
Rock is broken in place by
Solve one, graded on the server
The trap
Using weathering and erosion as the same word. Weathering never carries anything. If material moved, that part of the answer is erosion, and an examiner marks the distinction.