The BGS Lexicon of Named Rock Units — Result Details

Ingham Sand and Gravel Formation

Computer Code: ISAG Preferred Map Code: notEntered
Status Code: Full
Age range: Early Pleistocene Epoch (QPE) — Mid Pleistocene Epoch (QPM)
Lithological Description: Formation encompasses fluvial, lacustrine and organic deposits of the pre-Glacial Bytham River. Deposits of four separate terrace levels are recognized as members of the formation. Commonly a basal fine to coarse-grained sandy gravel is overlain by fine- to coarse-grained pebbly sands, with few clay and silt beds. The gravels contain a high proportion (up to 54%) of rounded pebbles of grey and purple "Bunter" quartzite of Triassic derivation, up to 47% vein quartz, and up to 56% flint derived from the local Chalk. There are traces of chalk and of igneous and metamorphic rocks. Sedimentary structures indicate deposition by braided rivers. The formation can be distinguished from formations of the Kesgrave Subgroup by the high ratio of quartzite to vein quartz in the gravels.
Definition of Lower Boundary: Unconformable on bedrock of the Chalk Group and Crag Group.
Definition of Upper Boundary: Commonly overlain by Mid Pleistocene glacigenic deposits. Upper boundary may be difficult to determine where overlain by glaciofluvial sand and gravel, but the presence of more angular clasts, chalk, and poorer sorting in the latter is usually helpful.
Thickness: c.13.2m
Geographical Limits: Recognised over a wide area of central East Anglia, from the Lark Valley in the west, to Knettishall in the valley of the Little Ouse, and along the valley of the Waveney to the North Sea coast at Pakefield and Kessingland.
Parent Unit: Bytham Catchments Subgroup (BYCA)
Previous Name(s): Ingham Sands And Gravels (-2868)
Bytham Sands And Gravels (*174)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Gravel pit 550m north of Ingham. Lewis and Bridgland, 1991. 
Reference(s):
Clarke, M R and Auton, C A. 1982. The Pleistocene history of the Norfolk-Suffolk borderlands. Institute of Geological Sciences Report 82/1, 23-29. 
Lewis, S J and Bridgland, D R. 1991. Ingham and Timworth. 71-83 in Lewis, S J, Whiteman, C A, and Bridgland, D R (editors), Central East Anglia and the Fen Basin. Field Guide. [London: Quaternary Research Association.] 
Hamblin, R J O, and Moorlock, B S P. 1995. The Kesgrave and Bytham Sands and Gravels of eastern Suffolk. Quaternary Newsletter, No.77, 17-31. 
Hopson, P M and Bridge, D M. 1987. Middle Pleistocene stratigraphy in the lower Waveney valley, East Anglia. Proceedings of the Geologists' Association, Vol.98, 171-185. 
Clarke, M R and Auton, C A. 1984. Ingham Sand and Gravel. 71-72 in Allen, P (Editor): Field Guide to the Gipping and Waveney valleys, Suffolk. [Cambridge: Quaternary Research Association.] 
Lewis, S G. 1999. Eastern England. 10-27 in Bowen D Q (editor), A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, 23. [London: Geological Society.] 
Mathers, S J, Horton, A and Bristow, C R. 1993. Geology of the country around Diss, Memoir of the British Geological Survey, l Sheet 175 (England & Wales). 
Bristow, C R. 1990. Geology of the country around Bury St Edmunds. Memoir of the British Geological Survey, Sheet 189 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E175 E189 E174 E176 E190