The BGS Lexicon of Named Rock Units — Result Details

Middle Devonian Limestone

Computer Code: MDVL Preferred Map Code: notEntered
Status Code: Full
Age range: Mid Devonian Epoch (DM) — Mid Devonian Epoch (DM)
Lithological Description: Variable across the area and at single locations, but dominated by dark and pale grey, purplish or black crinoidal and coralline limestone, with local staty intercalations of limited lateral extent. Some red shaly compact limestone. Locally, around Yealmpton, dolomite is present, both as massive beds and as intercalated layers with non-dolomitised limestone. Around Buckfastleigh, thick-bedded grey limestones are exposed in several quarries.
Definition of Lower Boundary: Thrust contacts which bring the limestones in to faulted contact with many other rock units.
Definition of Upper Boundary: Thrust contacts, which bring the limestones in to contact with many other rock units.
Thickness: Not known.
Geographical Limits: In a band of varying width, trending approximately east-west across south Devon and Cornwall: from Newton Abbot (in south Devon)[SX 8582 7166] to Trevose Head (on the north Cornwall coast) [SW 8474 7630]. Modern nomenclature includes rocks of Middle Devonian age - see 'alternative names' section.
Parent Unit: Not Applicable (-)
Previous Name(s): none recorded or not applicable
Alternative Name(s): Chercombe Bridge Limestone Formation
Denbury Crinoidal Limestone Formation
East Ogwell Limestone Formation
Prince Rock Member
Plymouth Limestone Formation
Marble Cliff Limestone Member
Pulsford Limestone Formation [Obsolete: use PUL]
Faraday Road Member
Stratotypes:
none recorded or not applicable
Reference(s):
Ussher, W A E, Barrow, G and MacAlister, D A. 1909. The Geology of the country around Bodmin and St. Austell. Explanation of sheet 347. Memoirs of the Geological Survey. 
Reid, C, Barrow, G and Dewey, H. 1910. The geology of the country around Padstow and Camelford. Explanation of sheets 335 and 336. Memoir of the British Geological Survey, England and Wales. 
Ussher, W A E. 1903. The Geology of the country around Torquay. Explanation of sheet 350. Memoirs of the Geological Survey. 
Ussher, W A E, by Lloyd, W. 1933. The Geology of the country around Torquay. Explanation of sheet 350. Memoirs of the British Geological Survey. 
Ussher, W A E. 1912. The Geology of the country around Ivybridge and Modbury. Explanation of sheet 349. Memoirs of the Geological Survey. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E350