Welcome to our guide to the geology of Devon. Developed in partnership with the Devon RIGS Group, this webpage contains guides to 13 different rock types found in Devon.

Click on either the map or the rock name in the key below to open a PDF which contains:

• a basic description of the rock type
• a more technical explanation of the geology
• photographs of the rock type
• how the rock type has been used
• recommendations of where the rock type can be visited

Also, at the bottom of this page there are links to an ‘Introduction to the Geology of Devon’ and a document called ‘Devon Geology Guide’ which is a compilation of all 13 rock type guides.

SUMMARY MAP OF THE GEOLOGY OF DEVON

KEY

Quaternary Deposits and Landforms (315KB - pdf help)	These recent deposits are not on the map	Permian Breccias, Sandstones and Volcanics (466KB - pdf help)
Tertiary Deposits (301KB - pdf help)		Dartmoor Granite (383KB - pdf help)
Lundy Granite (202KB - pdf help)		Carboniferous Sandstones and Shales (431KB - pdf help)
Chalk (438KB - pdf help)		Transition Group (Devonian to Carboniferous boundary)
Upper Greensand and Gault (436KB - pdf help)		Devonian Slates, Sandstones and Volcanics (371KB - pdf help)
Lower Jurassic Mudstones and Limestones (468KB - pdf help)		Devonian Limestones (309KB - pdf help)
Triassic Pebble Beds, Sandstones and Mudstones (322KB - pdf help)		Lower Devonian Schists (397KB - pdf help)

FURTHER INFORMATION

• Introduction to the Geology of Devon (33KB - pdf help)
• Devon Geology Guide (2.53MB - pdf help)
• Safety when Visiting Sites of Geological Interest (18KB - pdf help)

The information on this page was developed in celebration of the International Year of Planet Earth. The 13 guides to the rock types were written by a team of consultants within David Roche GeoConsulting. The Basic Description sections have been subsequently edited by Devon County   Council.