What are Sedimentary Rocks, Types and Formation

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What are Sedimentary Rocks?

Sedimentary rock is a type of rock that is formed from a deposit of small pieces of different rocks, which form strata or layers and harden up through a process known as lithification.

Sedimentary rocks are characterized by ripple marks or mud cracks, different layers of rocks, and color. Also, sedimentary rocks are soft and can be easily broken into pieces.


Types of Sedimentary Rocks

There are basically three types of sedimentary rocks – Clastic, Organic or Biological, and Chemical sedimentary rocks.

What are sedimentary rocks

How Are Sedimentary Rocks Formed?

Sedimentary rocks are organic in origin because the processes of their formation are derived by some processes which include weathering, erosion, transportation, and deposition of preexisting rocks.

The implication of this definition is that sedimentary rock is brought about by the actions listed above acting on an existing rock with the transformation into sedimentary.

The process of cementation, in which rock cracks or other organic materials derived from other rocks are cemented together after the initial process of suspension.

The processes may be termed geological. Another basic process that is important in a sedimentary rock formation is precipitation.


Classification and Examples of Sedimentary Rocks

  • Shale

This is the ore common sedimentary rock formed by the construction of mud sediment consisting of a mixture of silt and clay.

They are rich in clay minerals which include feldspars, micas. They are equally fine-grained in texture.


  • Limestone

This is a solution of calcium carbonate that becomes limestone and it is the type mostly formed when there is enough water to cause a solution of the carbonate solid resulting from sedimentation or settling down.


  • Conglomerates

These are colloidal materials especially clay particles that are of rock fragments.

It consists of a mixture of material which includes rock fragments and colloidal clay.

It is unsorted other types of sedimentary rock includes coal, gypsum, rock salt, phosphate rock.

Other examples of sedimentary rocks are siltstone, breccia. sandstone etc.