The BGS Lexicon of Named Rock Units — Result Details

Witham Valley Formation

Computer Code: WIVY Preferred Map Code: notEntered
Status Code: Full
Age range: Mid Pleistocene Epoch (QPM) — Holocene Epoch (QH)
Lithological Description: The formation encompasses the fluvial, lacustrine and organic deposits of the River Witham and its tributaries. It includes floodplain alluvium and deposits of three river terraces. The floodplain alluvium comprises soft clays, silts and fine sands, with bodies of peat, overlying sands and gravels. The terrace deposits are dominantly sands with some gravelly sands, sandy gravels and gravels. Sands are dominantly pale brown to orange brown, quartzose, fine- to medium-grained, clean and well sorted. Pebble fractions are dominantly bioclastic limestone, siltstone, ironstone and phosphatic nodules derived from the Lias Group and Lincolnshire Limestone Formation, with additionally some angular to subrounded quartz, "Bunter" quartzite, ironstone, chert and sandstone.
Definition of Lower Boundary: Unconformable on Middle Pleistocene glacial deposits, and on Jurassic bedrock.
Definition of Upper Boundary: Surface.
Thickness: To c.13m
Geographical Limits: The entire catchment of the River Witham and its tributaries, from around Boston to around Claypole, Lincolnshire.
Parent Unit: Ouse-Nene Catchments Subgroup (ONCA)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Valley of the River Witham from Boston to Claypole, Lincolnshire. Berridge et al., 1999. 
Reference(s):
Berridge, N G, Pattison, J, Samuel, M D A, Brandon, A, Howard, A S, Pharaoh, T C and Riley, N J. 1999. Geology of the Grantham district. Memoir of the British Geological Survey, sheet 127 (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E127 E128 E115 E114 E102