The BGS Lexicon of Named Rock Units — Result Details

Bacton Green Till Member

Computer Code: BGTI Preferred Map Code: notEntered
Status Code: Full
Age range: Pleistocene Epoch (QP) — Pleistocene Epoch (QP)
Lithological Description: The Bacton Green Till Member forms an extensive diamicton complex that consists of a stratified assemblage of stony diamicton with beds/laminae of sorted material including sand, silt and clay. It has been interpreted as being a subaqueous till deposited by melt-out and gravity flows (Lunkka, 1994; Lee et al., 2004). The calcium carbonate content of the matrix of the diamicton beds is typically within the region of 10-12% and is some 20% lower than tills from the underlying Lowestoft Formation.
Definition of Lower Boundary: The Bacton Green Till Member exhibits a gradational lower boundary with either the Mundesley Sand Member (outwash sands) or the Runton Till Member (subglacial till) of the Sheringham Cliffs Formation.
Definition of Upper Boundary: Commonly the upper boundary of the Bacton Green Till Member is erosional - for example where it is overlain by the Weybourne Town Till and Runton Cliffs Sand and Gravel members of the Sheringham Cliffs Formation, and the Stow Hill Sand and Gravel of the Briton's Lane Formation. More rarely, in the Trimingham area, the till grades upwards into the Trimingham Sand and Trimingham Clay members.
Thickness: Variable but generally in the range of 10-15m.
Geographical Limits: The Bacton Green Till Member crops out on the northeast Norfolk coast between Bacton Green and Sheringham.
Parent Unit: Sheringham Cliffs Formation (SMCL)
Previous Name(s): THIRD CROMER TILL
Alternative Name(s): none recorded or not applicable
Type Section  Coastal cliff sections some 800m northwest of Bacton Green beneath the Bacton Gas Terminal. Sections at this locality consist of a 10m-thick stratified diamicton comprising beds of stony mud separated by lenses and continuous beds of sand. The basal gradational contact with the Mundesley Sand Member is evident at the western end of the stratotype. 
Lee, J R, Booth, S J, Hamblin, R J O, Jarrow, A M, Kessler, H, Moorlock, B S P, Morigi, A N, Palmer, A, Riding, J B and Rose, J. 2004. A new stratigraphy for the glacial deposits around Lowestoft, Great Yarmouth, North Walsingham and Cromer, East Anglia, UK. Bulletin of the Geological Society of Norfolk, Vol.53, 3-60. 
Banham, P H. 1968. A preliminary note of the Pleistocene stratigraphy of northeast Norfolk. Proceedings of the Geologists' Association, Vol.79, 469-474. 
Lunkka, J P, 1994. Sedimentation and lithostratigraphy of the North Sea Drift and Lowestoft Till Formations in the coastal cliffs of northeast Norfolk, England. Journal of Quaternary Science, 9, 209-233. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable