The BGS Lexicon of Named Rock Units — Result Details

Trevose Slate Formation

Computer Code: TVS Preferred Map Code: notEntered
Status Code: Pending Upgrade
Age range: Eifelian Age (DI) — Frasnian Age (DR)
Lithological Description: Pale grey silty laminated dark grey slate with regular beds of structureless siltstone, from 0.03-0.10m thick, interbedded. Sporadic thin beds of sandstone and limestone also occur, the latter particularly in the upper part of the formation.
Definition of Lower Boundary: Conformable on Bedruthan Formation in cliffs [SW 8487 6993] near Queen Bess rock.
Definition of Upper Boundary: Conformable with the overlying Harbour Cove Formation in the cliff facing Lower Merope Island [SW 8943 7700].
Thickness: c.3900m
Geographical Limits: West of Bodmin Moor, to Pentire Point, Trevose Head and Park Head.
Parent Unit: Not Available (!)
Previous Name(s): C2 And C2-3 Slate (-3734)
Grey Slate (-2505)
Light Grey Slate (-1245)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Between Constantine Bay and Mackerel Cove. Gauss, G A and House, M R, 1972. 
Reference(s):
Selwood, E B, Thomas, J M, Williams, B J, Clayton, R, Durning, B, Smith, O and Warr, L N, 1998. Geology of the country around Trevose Head and Camelford. Memoir of the British Geological Survey, sheets 335 and 336 (England and Wales). 
House, M R, 1961. The Devonian successions of the Padstow area. Abstract of the Proceedings of the 3rd conference on the geology and geomorphology of south-west England, 4-5. 
Gauss, G A, 1966. Some aspects of slaty cleavage in the Padstow area of North Cornwall. Beese, A P, 1982. The Argillite facies of the middle Devonian succession in north Cornwall. Proceedings of the Ussher Society, Vol.5, 321-332. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable