* Weathering: This is the breakdown of rocks, soils, and minerals through direct contact with the Earth's atmosphere, water, and biological organisms. It can be:
* Physical weathering: Breaking rocks into smaller pieces without changing their chemical composition. Examples include frost wedging, abrasion, and root wedging.
* Chemical weathering: The breakdown of rocks by chemical reactions. Examples include oxidation, hydrolysis, and dissolution.
* Erosion: The process of moving weathered rock and soil from one location to another. This is primarily caused by:
* Wind: Wind can carry sand and dust, eroding rock surfaces.
* Water: Rivers, streams, and ocean waves can erode rock and transport sediment.
* Ice: Glaciers can carve out valleys and transport large amounts of rock.
* Gravity: Mass wasting, like landslides and mudslides, can move material downhill.
* Deposition: The process by which eroded material is dropped or settled in a new location. This can occur when:
* Water slows down: Rivers and streams deposit sediment as they enter lakes or oceans.
* Wind speed decreases: Wind carries dust and sand, which settle when the wind slows down.
* Glaciers melt: Melting glaciers deposit sediment as they retreat.
* Burial and Compaction: Sediments deposited in layers are buried over time, increasing the pressure on the lower layers. This pressure compacts the sediment, squeezing out water and reducing pore space.
Important Note: While the rock cycle is often depicted as a continuous loop, these surface processes are important steps in the formation of sedimentary rocks. These rocks can then be subjected to heat and pressure deep within the Earth, leading to the formation of metamorphic rocks, and eventually, through melting, to igneous rocks.
