The BGS Lexicon of Named Rock Units — Result Details

Portscatho Formation

Computer Code: PORO Preferred Map Code: Pto
Status Code: Full
Age range: Givetian Age (DV) — Frasnian Age (DR)
Lithological Description: Interbedded sandstone beds (up to 2m) and slaty mudstone.
Definition of Lower Boundary: Carrick Thrust.
Definition of Upper Boundary: Veryan Thrust.
Thickness: Up to 5.4km.
Geographical Limits: Gramscatho Basin, South Cornwall.
Parent Unit: Gramscatho Group (GRO)
Previous Name(s): Falmouth Beds [Obsolete Name And Code: Use PORO] (FAB)
Grampound And Probus Series (-4266)
Lower Gramscatho Beds (-4267)
Portscatho Series (-4268)
Portscatho Beds [Obsolete Name And Code: Use PORO] (PTB)
Lower Gramscathos [Obsolete Name And Code: Use PORO] (LGRO)
Falmouth Series (-465)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Gerrans Bay and Carrick Roads. South Cornwall. 
Reference(s):
Leveridge, B E, Holder, M T and Goode, A J J, 1990. Geology of the country around Falmouth. Memoir of the British Geological Survey, Sheet 352 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E352 E353 E354