GARY HINCKS / SCIENCE PHOTO LIBRARY GARY HINCKS / SCIENCE PHOTO LIBRARY
Coal formation, artwork. At top, plants grow around the edges of a swamp in the Carboniferous era, between 345 and 280 million years ago. As the plants die, they fall into the water. This anaerobic environment prevents their decay, and a thick layer of dead plant material (brown) forms. As the swamp fills in, the layer becomes covered in sediment (second panel down) and the pressure from successive layers compresses the plant matter into peat (dark band, third panel). Over time, increased pressure and heat convert the peat into coal (black band, bottom).
Model release not required. Property release not required.