The initial accumulation occured in various wet environments, commonly peat swamps, where dying plant material was largely protect from decay by a high water table and anoxic water (in swamps, etc. where there is very little water motion, only the top few centimeters is aerobic). Present day examples of this type of depositional environments are; the Florida Everglades, the Okefenokee Swamp in Georgia and Florida, and the Dismal Swamp in Virginia.

The Florida Everglades