The BGS Lexicon of Named Rock Units — Result Details

Low Water Tuff Formation

Computer Code: LWW Preferred Map Code: LwW
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Welded dacitic lapilli tuffs with subordinate interbedded volcaniclastic sandstone and tuff.
Definition of Lower Boundary: Formation unconformably overlies the Paddy End Tuff Member of the Lickle Tuff Formation for most of its outcrop; at the southern end it overlies the Lag Bank Tuff Formation. The base is defined at the lowest extent of homogneous, fine, lapilli-tuff of dacite composition or, where present, the base of the underlying volcaniclastic sandstones.
Definition of Upper Boundary: Overlain by Seathwaite Fell Sandstone Formation; abrupt change to volcaniclastic sandstone.
Thickness: To c.400m
Geographical Limits: Low Water (SD 275 982) to Greenburn Beck (NY 310 030), Coniston Fells, Lingmoor Fell (NY 300 035), Cumbria.
Parent Unit: Borrowdale Volcanic Group (BVG)
Previous Name(s): Low Water Formation (-1675)
Lingmoor Fell Formation [Obsolete Name: Part Of LWW] (LRF)
Alternative Name(s): none recorded or not applicable
Type Area  Lad Stones, above Beck Fells, Coniston, Cumbria. 
Millward, D, Johnson, E W, Beddoe-Stephens, B, Young, B, Kneller, B C, Lee, M K, Fortey, N J, Allen, P M, Branney, M J, Cooper, D C, Hirons, S, Kokelaar, B P, Marks, R J, McConnell, B J, Merritt, J W, Molyneux, S G, Petterson, M G, Roberts, B, Rundle, C C, Rushton, A W A, Scott, R W, Soper, N J and Stone, P. 2000. Geology of the Ambleside district. Memoir of the British Geological Survey, England and Wales, Sheet 38. 
Mitchell, G H, 1940. The Borrowdale Volcanic Series of Coniston, Lancashire. Quarterly Journal of the Geological Society of London, Vol.96, p.301-319. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: