* Oil and natural gas: Most of the world's oil and natural gas reserves are located in the Middle East, with other significant deposits in North America, South America, Africa, and Asia.
* Coal: The largest coal reserves are found in the United States, China, Russia, India, and Australia.
These deposits are the result of millions of years of plant and animal matter accumulating in these basins and being subjected to heat and pressure. Over time, the organic matter transforms into oil, natural gas, and coal.