The BGS Lexicon of Named Rock Units — Result Details

Fen Gravel

Computer Code: FEG Preferred Map Code: notEntered
Status Code: Index Level
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Sands and gravels (including pebbly sands and sandy gravels), some clayey or silty with some silts and clays. The distal (seaward) portions include marine shells.
Definition of Lower Boundary: Rests unconformably on bedrock or on older (mostly glacial) Quaternary deposits.
Definition of Upper Boundary: Contact with pebbly, silty, sandy clays and clayey sands of the Crowland Bed (Booth, 1982), or unconformably overlain by Flandrian deposits. In the absence of the Crowland Bed, the distal portions of the Fen Gravel may not be separable from the lowest Flandrian deposits.
Thickness: 0 to c.10m
Geographical Limits: Exposed intermittently at the margins of Fenland in Lincolnshire, Northamptonshire, Huntingdonshire, Cambridgeshire, Suffolk and Norfolk, especially at the western and southern margins. Presumed widespread at depth within Fenland. As used, includes the distal portions of river terrace systems entering Fenland, but by implication excludes parts of the same river systems outside Fenland. It is therefore not a valid lithostratigraphical division, but seems a useful term to retain in the broad sense of Skertchly (1877).
Parent Unit: Not Applicable (-)
Previous Name(s): Fen Gravel (FEG)
Fen And Terrace Gravel (-243)
Fen-Margin Gravel (-3397)
Alternative Name(s): March Gravels, Abbey Sand And Gravel,First Terrace Deposits,Etc.
Stratotypes:
Type Area  Representative components occur within a 10 km radius of Peterborough. 
Reference(s):
Skertchly, S B J. 1877. The geology of Fenland. Memoir of the Gological Survey of Great Britain. 
Castleden, R. 1980. The second and third terrace of the River Nene. Mercian Geologist, Vol.8, 29-46. 
Horton, A. 1989. Geology of the Peterborough district. Memoir of the British Geological Survey, Sheet 158 (England & Wales). 
Booth, S J. 1982. The sand and Gravel resources of the country around Whittlesey, Cambridgeshire: Description of 1:25000 sheets TF 20 and TL 29. Mineral assessment report of the Institute of Geological Sciences, No. 93, 109 pp. 
Booth, S J. 1983. The sand and gravel resources of the country between Bourne and Crowland, Lincolnshire. Description of 1:25000 sheets TF 11 and parts of TF 01 and TF 21. Mineral Assessment Report of the Institute of Geological Sciences, No. 130, 191 pp. 
British Geological Survey, 1978. Stamford. England and Wales Sheet 157. Solid and Drift. 1:50000. (Southampton; Ordnance Survey for British Geological Survey). 
Prentice, J E.1950. The sub-surface geology of the Lincolnshire Fenland. Transactions of the Lincolnshire Naturalists' Union, Vol.12, 136 - 139. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E127 E128 E143 E144 E157