Sedimentary rocks are formed when sediment is deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension. This sediment is often formed when weathering and erosion break down a rock into loose material in a source area.

Sedimentary rocks are formed through a process known as sedimentation. This process involves the accumulation and consolidation of sediment particles over time. Here is a detailed explanation of how sedimentary rocks are formed:


- The process begins with weathering, which is the breakdown of rocks and minerals into smaller fragments.
- Weathering can occur through physical processes like freezing and thawing, as well as chemical processes like oxidation and dissolution.
- Once the rocks are weathered, erosion takes place, which involves the transportation of the fragmented material from its original location.
- Agents of erosion, such as wind, water, ice, and gravity, move the sediments to new areas.


- When the transported sediments reach a point where the energy of the transporting agent decreases, they are deposited.
- This can occur in bodies of water such as rivers, lakes, and oceans, as well as on land through wind deposition.
- The sediments settle and accumulate in layers, with the coarser particles usually deposited closer to the source and finer particles settling further away.


- As more and more sediment accumulates over time, the weight of the overlying layers compresses the sediments at the bottom.
- This compaction process reduces the pore spaces between the sediment particles, causing them to become more tightly packed.


- Cementation is the process where minerals precipitate and bind the sediment particles together.
- The minerals, often dissolved in water, fill the spaces between the sediment grains and act as a glue, creating a solid rock.
- Common minerals involved in cementation include calcite, silica, and iron oxides.


- The combination of compaction and cementation leads to lithification, transforming the loose sediment into a solid sedimentary rock.
- The rock becomes more coherent and hardens, preserving the layers and structures formed during the deposition and compaction stages.


- There are three main types of sedimentary rocks: clastic, chemical, and organic.
- Clastic sedimentary rocks are composed of fragments of pre-existing rocks, while chemical sedimentary rocks are formed from dissolved minerals that precipitate out of water.
- Organic sedimentary rocks are derived from the accumulation and lithification of organic remains, such as plant materials or shells.

Overall, the formation of sedimentary rocks is a gradual process that involves weathering, erosion, deposition, compaction, cementation, and lithification. It is through these processes that the loose sediments are transformed into solid rocks, preserving the Earth's history and providing valuable insights into past environments.

Sedimentary Rocks: The word 'Sedimentary' is derived from Latin word "Sedimentum" meaning "Settle Down". Particles that form a sedimentary rock by accumulating are called sediments. Before being deposited, sediment was formed by weathering and erosion in a source area, and then transported to the place of deposition by water, wind, ice, mass movement or glaciers which are called agents of denudation.