The BGS Lexicon of Named Rock Units — Result Details

Ivy Farm Laminated Silt Member

Computer Code: IFLS Preferred Map Code: notEntered
Status Code: Full
Age range: Pleistocene Epoch (QP) — Pleistocene Epoch (QP)
Lithological Description: The Ivy Farm Laminated Silt Member consists of two distinctive lithofacies: (1) rhythmically-bedded dark grey clays and pale grey silts that grade upwards into a pale yellow laminated marl; (2) horizontally bedded and rippled fine-grained pale grey sand rich in the heavy mineral zircon.
Definition of Lower Boundary: Abrupt but conformable lower boundary with either the diamicton facies of the Walcott Till Member or the sandy facies of the Mundesley Sand Member.
Definition of Upper Boundary: In the Trimingham area, the upper boundary of the silts and clays of the Ivy Farm Laminated Silt Member is truncated by the diamicton facies of the Bacton Green Till Member.
Thickness: In excess of 22m. The true thickness is difficult to determine because the unit is truncated by several large-scale basal shear planes.
Geographical Limits: The Ivy Farm Laminated Silt Member can be identified and traced within cliff sections between Trimingham and Overstrand, north norfolk.
Parent Unit: Sheringham Cliffs Formation (SMCL)
Previous Name(s): Trimingham Clays (-4720)
Happisburgh Clays (-2862)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Cliff sections at Sidestrand, northeast Norfolk, approximately 1km northwest of the beach access at Trimingham. Within these sections, up to 22m of stratified silt, clay and sand can be observed. Lee, 2003. 
Reference(s):
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. 
Hart, J K. 1992. Sedimentary environments associated with Glacial Lake Trimingham, Norfolk, UK. Boreas, Vol.21, 119-136. 
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, Vol. 9, 203-233. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable