Sedimentary Rocks:
* Weathering: The breakdown of existing rocks into smaller pieces by physical (wind, water, ice) and chemical (acid rain, oxidation) processes.
* Erosion: The transport of weathered rock fragments by wind, water, or ice.
* Deposition: The settling of eroded rock fragments in a new location, often in layers.
* Compaction: The pressure of overlying layers squeezing out water and air, compacting the sediments.
* Cementation: Minerals dissolved in water precipitate between sediment grains, binding them together.
* Metamorphism: When existing sedimentary rocks are exposed to intense heat and pressure deep within the Earth, transforming them into metamorphic rocks.
Igneous Rocks:
* Cooling and Crystallization: Molten rock (magma or lava) cools and solidifies, forming crystals.
* Weathering and Erosion: Similar to sedimentary rocks, igneous rocks break down and are transported.
* Metamorphism: Intense heat and pressure can transform igneous rocks into metamorphic rocks.
In summary:
* Both sedimentary and igneous rocks can change through weathering, erosion, and deposition.
* Sedimentary rocks are formed by these processes, while igneous rocks are subject to them after their initial formation.
* Both types of rocks can undergo metamorphism to form new rock types.
Additional factors:
* Plate tectonics: The movement of Earth's plates can uplift or subduct rocks, leading to changes in pressure, temperature, and exposure to weathering.
* Biological activity: Organisms can contribute to weathering and erosion, and their remains can become incorporated into sedimentary rocks.
Note: The changes described above are gradual and can take millions of years.
