The BGS Lexicon of Named Rock Units — Result Details

Dam House Bridge Tuff Member

Computer Code: DHBT Preferred Map Code: DHBT
Status Code: Full
Age range: Rawtheyan Stage (OW) — Rawtheyan Stage (OW)
Lithological Description: Siltstone and mudstone with interbedded units of lithic crystal tuff, probably of silicic composition
Definition of Lower Boundary: Taken at the base of the lowest bed of volcaniclastic rock overlying calcareous siltstone and argillaceous limestones of the Norber Formation
Definition of Upper Boundary: Taken at the top of the last bed of tuff where it is overlain by siltstone and mudstone within the main part of the Sowerthwaite Formation
Thickness: Up to 40m
Geographical Limits: Restricted to the Austwick area of N Yorkshire
Parent Unit: Sowerthwaite Formation (SOW)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Type Section  Austwick Beck at Dam House Bridge, North Yorkshire Arthurton et al. 1988 
Arthurton, R S, Johnson, E W and Mundy, D J C. 1988. Geology of the country around Settle. Memoir of the British Geological Survey, Sheet 60 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used: