Formation of Coal
Coal is a fossil fuel that primarily forms from the remains of ancient trees and plants. This process takes millions of years and involves several key stages.
1. Accumulation of Plant Material
- The formation of coal begins in swampy areas where large quantities of dead plant material, particularly trees and other vegetation, accumulate.
- Over time, these remains become buried under sediment, creating an anaerobic (oxygen-poor) environment that slows down the decomposition process.
2. Peat Formation
- As layers of sediment build up, the pressure increases, causing the plant material to transform into peat.
- Peat is an accumulation of partially decayed organic matter, which is the precursor to coal.
3. Transformation into Coal
- With further burial and increased pressure and temperature, peat undergoes chemical changes. Over millions of years, it transforms into different types of coal: lignite, sub-bituminous, bituminous, and anthracite.
- Each type of coal has varying carbon content and energy potential, with anthracite being the highest quality.
4. Importance of Trees
- Trees and other terrestrial plants are crucial to the coal formation process because they provide the organic material necessary for coal creation.
- While animals and rocks play significant roles in Earth’s ecosystem, they do not contribute to the formation of coal.
In summary, the correct answer is option 'A' (Trees), as coal is primarily formed from the remains of ancient plant life, primarily trees, through a complex geological process.