1. Weathering: This is the breakdown of rocks into smaller pieces.
* Physical weathering: This involves mechanical forces that break down rocks.
* Frost wedging: Water seeps into cracks, freezes, expands, and breaks the rock apart.
* Abrasion: Rocks rub against each other, causing them to wear down. This can be caused by wind, water, or glaciers.
* Root wedging: Plant roots grow into cracks, expanding and breaking the rock.
* Chemical weathering: This involves chemical reactions that break down rocks.
* Acid rain: Rainwater mixed with pollutants can dissolve some minerals in rocks.
* Oxidation: The reaction of minerals with oxygen, like rusting, can break down rock.
2. Erosion: This is the movement of weathered rock material.
* Wind: Carries sand and dust, which can abrade rocks.
* Water: Rivers, waves, and rain can carry away weathered rock fragments.
* Glaciers: Massive ice sheets can grind and scrape rocks, carrying them away.
3. Tectonic forces: These are forces within the Earth's crust that cause mountains to form, continents to move, and earthquakes to occur.
* Folding: Rocks can be bent and folded, changing their shape.
* Faulting: Rocks can break and shift along fractures, creating new shapes.
* Metamorphism: Intense heat and pressure can change the texture and composition of rocks, sometimes creating entirely new minerals.
4. Impact events: When meteorites or asteroids strike the Earth, they can cause massive explosions and create craters, changing the shape and size of rocks in the surrounding area.
It's important to remember that these forces often work together to change rocks! For example, weathering can break a rock down into smaller pieces, which are then carried away by erosion. Tectonic forces can uplift rocks, making them more susceptible to weathering.
