1. Weathering:
* The Break Down: Weathering is the process of breaking down rocks, soils, and minerals through physical and chemical processes.
* Physical weathering: This involves mechanical forces like freezing/thawing, abrasion (rocks rubbing together), and plant roots.
* Chemical weathering: This involves chemical reactions, like oxidation (rusting) and acid rain, that alter the composition of rocks.
2. Erosion:
* The Movement: Erosion is the process of transporting weathered material from one location to another.
* Agents of erosion: The most common agents include:
* Water: Rivers, streams, waves, and rain are powerful eroding forces.
* Wind: Wind can carry sand, dust, and other particles, abrading surfaces and transporting material.
* Ice: Glaciers carve out valleys and transport large amounts of debris.
* Gravity: Gravity pulls rocks and soil downhill, causing landslides and other mass movements.
3. Deposition:
* The Drop-Off: Deposition is the process where eroded material is dropped or settled in a new location.
* Factors influencing deposition: The speed of the erosive agent, the size and weight of the material, and the change in the landscape all influence where and how material is deposited.
* Landforms created by deposition: Rivers create deltas and floodplains, glaciers deposit moraines, and wind creates sand dunes.
The Cycle:
Weathering creates loose material that can be picked up by erosive forces. These forces transport the material until they lose energy, causing deposition. The deposited material can then be weathered again, restarting the cycle.
Examples:
* A Mountain Range: Mountains are weathered by rain, frost, and wind. The eroded material is carried by rivers and glaciers, and eventually deposited in valleys or at the foot of the mountains, forming fertile soil or alluvial fans.
* A Beach: Waves erode the cliffs along a coastline, creating sand. The sand is then transported along the beach by currents and deposited in different locations, forming sandbars and spits.
In summary:
* Weathering breaks down rocks.
* Erosion moves weathered material.
* Deposition drops the material in a new place.
These processes work together to create the diverse landscapes we see around us.
