Question

Chalk and Charcoal are categorized under which type of sedimentary rocks?

• A. Chemically formed Rocks
• B. Mechanically formed Rocks
• C. Organically formed Rocks
• D. Igneous formed Rocks

Answer 1

Answer:

C. Organically formed Rocks

Sedimentary Rocks: Formation and Classification

• Sedimentary rocks are formed from the accumulation and cementation of mineral and organic particles on the Earth's surface, and in bodies of water.

• They are broadly classified into three main types based on their formation process: Clastic, Chemical, and Organic.

Organically Formed Rocks

• This category includes sedimentary rocks formed from the remains of living organisms, such as plants and animals.

• These materials, over geological time, accumulate and are compacted and cemented to form rock.

• Chalk is a prime example of an organically formed rock. It is a type of limestone composed of microscopic marine organisms, specifically coccolithophores, which are single-celled algae.

• Charcoal, while often a product of modern fires, can also be found in geological formations. In the context of sedimentary rocks, it is formed from the accumulation and compression of plant matter that has undergone partial decomposition and carbonization, often in swampy environments.

• Other examples of organically formed rocks include coal (formed from plant debris) and various types of limestone (formed from shells and skeletal fragments of marine organisms).