Devon’s rocks – a geological guide

This webpage contains guides to 13 different rock types found in Devon. We hope you find the information provided is appropriate for your requirement, either for leisure or study. Different levels of information are provided, which are designed for those with a general interest in rocks, along with more advanced technical descriptions.

Click on the map to enlarge and click on 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.

Summary map of the geology of Devon

Devon geology map

Quaternary Deposits and Landforms These recent deposits are not on the map Permian Breccias, Sandstones and Volcanics geo-permianbreccias
Tertiary Deposits  geo-tertiarydeposits Dartmoor Granite geo-dartmoorgranite
Lundy Granite geo-lundygranite Carboniferous Sandstones and Shales geo-carboniferoussandstonesshales
Chalk  geo-chalk Transition Group (Devonian to Carboniferous boundary) geo-transitiongroup
Upper Greensand and Gault  geo-uppergreensandgault Devonian Slates, Sandstones and Volcanics geo-devonianslatessandstonesvolcanics
Lower Jurassic Mudstones and Limestones  geo-lowejurassicmudstoneslimestones Devonian Limestones geo-devonianlimestones
Triassic Pebble Beds, Sandstones and Mudstones  geo-triassicpebblebeds Lower Devonian Schists geo-lowerdevonianschists

 

 

 

 

 

An ‘Introduction to the Geology of Devon’ travels back in time and summarises the history and variety of geology in Devon.  A document called ‘Devon’s Rocks – A Geological Guide’ provides a compilation of all 13 rock type guides.  The Educational Register of Geological Sites is designed to encourage the educational use of Devon’s fascinating and diverse geological and geomorphological heritage.

Visiting geological sites

 devon-rigs The information on this page was developed in celebration of the International Year of Planet Earth in partnership with the Devon RIGS Group. 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