Here's a breakdown:

* Formation: Coal forms over millions of years from the remains of ancient plants buried under layers of sediment, typically in swampy environments. The pressure and heat from the layers of sediment transform the plant material into coal.

* Geological Location: This process often occurs in areas that were once low-lying, swampy regions with abundant plant life. These areas are typically found in ancient sedimentary basins, where layers of sediment have accumulated over long periods.

* Examples: Some of the major coal-producing regions in the world include:

* Appalachian Basin (United States): Known for its bituminous coal deposits.

* Illinois Basin (United States): Home to significant deposits of bituminous and sub-bituminous coal.

* Powder River Basin (United States): A major source of sub-bituminous coal.

* Donbas (Ukraine): Famous for its anthracite coal deposits.

* Ruhr Valley (Germany): Once a major coal mining region.

* Sydney Basin (Australia): Known for its bituminous coal deposits.

It's important to note that the distribution of coal deposits can vary greatly depending on the geological history of a region.