Formation of Fossil Fuels Lecture Notes

Introduction

• Aim: By the end of the video, be able to describe how fossil fuels are formed: including coal, oil, and gas.
• Context: Previous video discussed changes in atmospheric gases over time.
  • Early atmosphere: High carbon dioxide, low oxygen.
  • Present atmosphere: High oxygen, low carbon dioxide.
• Role of photosynthesis:
  • Takes in CO2, produces oxygen.
  • Some carbon ends up in fossil fuels.

Fossil Fuels Overview

• Fossil fuels are formed over millions of years.
• They are non-renewable: continued usage will lead to depletion.

Formation of Coal

• Origin: Remains of ferns and trees.
• Conditions for formation:
  • Occurs in marshy wetlands.
  • Lack of decomposition due to:
    • Low oxygen.
    • Acidic conditions that inhibit bacteria.
• Process:
  • Plant remains covered with sediment.
  • Compressed under high temperature and pressure to form coal.

Formation of Oil

• Origin: Plankton (tiny plants and animals) found in the sea.
• Conditions for formation:
  • After death, plankton settles in mud on the seabed.
  • Lack of oxygen prevents decomposition.
• Process:
  • Compressed by sediment.
  • Heat and pressure transform it into crude oil.

Formation of Natural Gas

• Composition: Mainly the hydrocarbon methane.
• Often found near oil deposits.
• Formation process similar to oil:
  • From plankton.
  • Formation process involves compression and transformation under heat and pressure.

Key Facts

• Fossil fuels contain trapped carbon.
• This carbon was part of CO2 taken in by photosynthesis.

Future Topics

• Upcoming video will discuss the effects of burning fossil fuels on the planet.

Additional Resources

• Questions and exercises on fossil fuels available in the workbook.