1. Weathering and Erosion: The first step is the breaking down of existing rocks (igneous, metamorphic, or even other sedimentary rocks) into smaller pieces through weathering (chemical and physical breakdown) and erosion (transportation of the broken pieces).
2. Transportation and Deposition: The weathered sediment is transported by wind, water, or ice, and eventually deposited in a new location, like a lake, ocean, or riverbed.
3. Burial and Compaction: Over time, layers of sediment accumulate, burying the earlier layers. The weight of the overlying layers compresses the sediment, squeezing out water and air. This process is called compaction.
4. Cementation: Dissolved minerals in groundwater precipitate between the sediment grains. These minerals act as a cement, binding the grains together. This process is called cementation.
5. Diagenesis: This is a broader term that encompasses all the physical and chemical changes that occur after deposition, including compaction, cementation, and other processes like recrystallization and dissolution.
Here is a simplified breakdown:
* Sediment: Loose particles of rock, minerals, and organic matter.
* Compaction: The pressure of overlying sediment squeezes out water and air.
* Cementation: Dissolved minerals crystallize between sediment grains, binding them together.
* Sedimentary Rock: A solid, coherent rock formed from sediment.
Examples of sedimentary rocks:
* Sandstone: Formed from cemented sand grains.
* Shale: Formed from compacted clay particles.
* Limestone: Formed from cemented shells and other marine debris.
* Coal: Formed from compacted plant remains.
The process of lithification can take millions of years, but it ultimately transforms loose sediment into solid rock.
