300 MILLION YEARS AGO Britain lay on the equator. Giant dragonflies flew through swampy forests of giant mosses and tree ferns. It was very hot and humid.
When the plants died they formed thick layers of peat which were squashed to form coal. The coal seams occur with sandstones and mudstones in repeating cycles that reflect the battle between land and sea. The Coal Measures are rich in fossils such as huge amphibians, spiny sharks, enamel scale fishes, mussels and marine shells.
The industrial revolution has left many traces in this landscape, including the now derelict Barnsley Canal, shown in the sketch here at Walton, near Wakefield.
Millstone Grit Magnesian Limestone Rocks of West Yorkshire Wild West Yorkshire home page