The BGS Lexicon of Named Rock Units — Result Details

Fenland Formation

Computer Code: FEND Preferred Map Code: notEntered
Status Code: Full
Age range: Hoxnian Stage (QX) — Holocene Epoch (QH)
Lithological Description: Formation encompasses the marine, estuarine and terrestial deposits that were formed in the Fens and adjacent areas during the Holocene and previous interglacial periods. The complex includes fresh and brackish water peats, salt marsh clays, fluvial silts and fine-grained sands, marine sands, and beach-face sands and gravels. In centre of the Fen Basin, five stratigraphical units are present. In ascending order these are basal sand and gravel, the Fen Lower Peat, Barroway Drove Beds, Nordelph Peat and Terrington Beds. Barroway Drove Beds comprise intertidal soft grey clays and silty clays cut by tidal channels and creeks infilled with silt and fine-grained sand. Terrington Beds comprise marine and brackish water silts and fine-grained sands. Marine sands and gravels marginal to the Fen Basin are the Woodstone Member (silty clays and fine sands), the March Gravel Member (sandy gravel to clayey pebbly sand) and the Abbey Sand and Gravel Member (clayey, sandy gravels).
Definition of Lower Boundary: Unconformable of glacial deposits and upon Jurassic and Cretaceous bedrock.
Definition of Upper Boundary: Surface.
Thickness: c.35m
Geographical Limits: The Fens of Cambridgeshire and Lincolnshire, and continuing along the coast of Lincolnshire as far as Humberston near Cleethorpes.
Parent Unit: British Coastal Deposits Group (COAS)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  The Fens of Cambridgeshire and Lincolnshire. Gallois, 1994. 
Reference(s):
Ventris, P A. 1985. Pleistocene environmental history of the Nar Valley, Norfolk. PhD, University of Cambridge. 
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.] 
Gallois, R W, 1994. The geology of the country around King's Lynn and The Wash. Memoir of the British Geological Survey, Sheet 145 and part of 129 (England and Wales). 
Horton, A. 1989. Geology of the Peterborough district. Memoir of the British Geological Survey, Sheet 158 (England & Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable