The BGS Lexicon of Named Rock Units — Result Details

Town End Farm Tuff Member

Computer Code: TOEF Preferred Map Code: notEntered
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: Massive, homogeneous, pumice-rich to pumice-poor eutaxitic and parataxitic lapilli-tuff with "autobrecciated" zones and basal lithic breccia.
Definition of Lower Boundary: At base of homogeneous welded lapilli tuff, at the base of the lithic rich basal breccia if it is present. This is the basal member of the Fleming Hall Formation; it rests on the Brown Bank Ignimbrite Formation.
Definition of Upper Boundary: At sharp upward change to pyroclastic breccia of the Sides Farm Member.
Thickness: 155m in type section (120m - bh4; 150m in RCF3)
Geographical Limits: Sellafield boreholes Nos 2 (NY00SE/28), 4 (NY00SE/29), 5 (NY00SE/30, 10A (NY00SW/38), RCF1 (NY00SE/35), RCF2 (NY00SE/36), RCF3 (NY00SE/37), RCM1 (NY00SE/41), RCM2 (NY00SE/40) and RCM3 (NY00SE/39).
Parent Unit: Fleming Hall Tuff Formation (FLH)
Previous Name(s): Town End Farm Member (-2493)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Sellafield borehole No5, BGS Registered No NY00SE/30 (736.95 - 892.42m below Rotary Table Elevation, 651.32 -806.79m below OD. 
Reference(s):
Akhurst, M C, Chadwick, R A, Holliday, D W, McCormac, M, McMillan, A A, Millward, D, Young, B, Ambrose, K, Auton, C A, Barclay, W J, Barnes, R P, Beddoe-Stephens, B, James, J C W, Johnson, H, Jones, N S, Glover, B W, Hawkins, M P, Kimbell, G S, MacPherson, K A T, Merritt, J W, Milodowski, A E, Riley, N J, Robins, N S, Stone, P and Wingfield, R T R. 1997. The geology of the west Cumbria district. Memoir of the British Geological Survey, Sheets 28, 37 and 47 (England and Wales). 138pp. 
Beddoe-Stephens, B and Millward, D, 2000. Very densely welded, rheomorphic ignimbrites of homogeneous intermediate calc-alkaline composition from the English Lake District. Geological Magazine, Vol.137, 155-173. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable