Doog.dog

Coal is often called “buried sunshine” because it is essentially solar energy stored in plant form from millions of years ago. Here is the step-by-step scientific process:

1. The Accumulation Phase (The Giant Swamps)

During the Carboniferous Period (roughly 300 to 360 million years ago), the Earth was much warmer and more humid. Vast, dense forests of giant ferns, reeds, and mosses grew in massive low-lying swamps.

2. The Preservation Phase (Stagnant Water)

When these ancient plants died, they fell into the swamp water. In normal forests, dead wood rots away. However, swamp water is oxygen-poor (anaerobic). This lack of oxygen prevented bacteria from fully decomposing the organic matter, creating a thick layer of soggy, brown material known as Peat.

3. The Burial Phase (Sedimentation)

Over millions of years, the Earth’s surface changed. Seas rose, and rivers moved, covering the peat layers with heavy sediments like mud, sand, and clay. The sheer weight of these layers created immense Pressure.

4. The Chemical Transformation (Coalification)

As the peat was buried deeper, it encountered two main forces:

• Extreme Pressure: Compressed the material and squeezed out water.
• Geothermal Heat: Acted like a “slow cooker,” driving off gases (like methane) and leaving behind mostly Carbon.

5. The Ranking of Coal

The longer the “cooking” process continues, the higher the carbon content and the energy density of the coal:

1. Lignite: The lowest rank; soft, brown, and high in moisture.
2. Sub-bituminous & Bituminous: Dense, black, and the most widely used for electricity.
3. Anthracite: The highest rank; very hard, shiny, and burns with the highest heat and least smoke.

Why is it found in Mountains?

The coal stayed deep underground until Tectonic Plate Movements occurred. When plates collided, they buckled and folded the Earth’s crust, pushing the deep coal seams upward to form Mountain Ranges. This is why we often find coal mines in mountainous regions today.

Summary Table: The Evolution

Stage	Description	Carbon Content
Peat	Partially decayed plant matter	Low
Lignite	“Brown coal,” soft and crumbly	Moderate
Bituminous	“Soft coal,” used in industry	High
Anthracite	“Hard coal,” high energy