Permian Period
Age : 248 to 290 million years ago
Geography, environment and climate
Britain formed part of Pangea, a landmass comprising all of the major continents. Desert conditions prevailed over much of Pangea, which lay near the Equator. An inland sea (the Zechstein Sea) occupied much of the area that is now the North Sea.
Key events
At the end of the Permian a mass extinction took place when three quarters of known species of land animals and 96% of marine animals became extinct. Groups such as the trilobites disappeared forever.
Rock types and occurrence in England
Sandstones formed from desert sand dunes can be found across England from Dawlish in south Devon to County Durham. Erosion of the uplifted mountain areas (e.g. Dartmoor) led to the deposition of thick fans of sediment along their flanks. This material now forms the cemented breccias of East Devon and Worcestershire.
Shallow marine limestones and associated evaporites (salts) deposited in the Zechstein Sea now form the Magnesian Limestone. This outcrops in a narrow band from Nottinghamshire, through central England to the Durham coast.
