Fossil fuels are formed from the remains of ancient organisms that lived millions of years ago. For coal, these organisms were primarily ancient plants that lived in swampy environments. Over time, the remains of these plants were buried under layers of sediment and subjected to high temperatures and pressure, leading to the formation of coal. Oil and natural gas, on the other hand, are formed from the remains of marine organisms such as algae and plankton. When these organisms die, their remains settle on the ocean floor and are eventually covered by layers of sediment. Over millions of years, heat and pressure transform these organic remains into the hydrocarbons that make up oil and natural gas. This process of fossil fuel formation is known as diagenesis. The specific conditions under which fossil fuels are formed, such as temperature, pressure, and the type of organic material involved, determine the type and quality of the fossil fuel that is produced. Understanding the geology behind the formation of fossil fuels is crucial for locating and extracting these valuable resources.