The BGS Lexicon of Named Rock Units — Result Details

St Germans Tuff Member

Computer Code: SGTU Preferred Map Code: SGTM
Status Code: Full
Age range: Givetian Age (DV) — Givetian Age (DV)
Lithological Description: Carbonate cemented basic lava and hyaloclastite fragments, massive basic lava and bedded lithic tuffs.
Definition of Lower Boundary: Conformable with slate and mudstone of undivided Saltash Formation below.
Definition of Upper Boundary: Conformable with slate and mudstone of undivided Saltash Formation above.
Thickness: Up to 175m.
Geographical Limits: Liskeard to Plymouth.
Parent Unit: Saltash Formation (SAH)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  River cliff. River Lynher, 1.25km east-south-east of St Germans. 
Reference(s):
Leveridge B E, Holder, M T, Goode, A J J, Scrivener R C, Jones N S and Merriman, R J. 2002. Geology of the Plymouth and south-east Cornwall area. Memoir of the British Geological Survey, Sheet 348 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E348 E349