What event in history led to the formation of fossil fuels?

Fossil fuels formed primarily from the remains of ancient plants and animals that lived millions of years ago, particularly during the Carboniferous period, around 300 million years ago. As these organisms died, they were buried under layers of sediment and subjected to intense heat and pressure over millions of years, leading to the chemical transformation into coal, oil, and natural gas. This process, known as fossilization, is crucial for the formation of fossil fuels, which are now significant energy sources.