The BGS Lexicon of Named Rock Units — Result Details

Martin Sand And Gravel Member

Computer Code: MTNSG Preferred Map Code: notEntered
Status Code: Full
Age range: Pleistocene Epoch (QP) — Pleistocene Epoch (QP)
Lithological Description: Predominantly cold-phase sands and gravels that underlie the Martin Terrace of the lower Witham valley. At surface, dominated by rounded pebbles of "Bunter" quartz/quartzite with subordinate subangular flint, etc. Terrace preserved as extensive dissected remnants at c.+18m in the Type Area, i.e about 16m above the Witham Floodplain there. Correlated with the Eagle Moor Sand and Gravel west of the Lincoln Gap.
Definition of Lower Boundary: Unconformable, commonly channelled base, resting on Anglian Wragby Till (Lowestoft Formation) or (locally) Middle to Upper Jurassic bedrock.
Definition of Upper Boundary: Ground surface.
Thickness: 0 to c.7m
Geographical Limits: Distributed mainly along the southwest side of the present Witham valley from Heighington [TF 04 69] to Billinghay [TF 14 55]; less well developed on the east side of the Witham valley (where it might be represented by the Tattershall Airfield Member (see Reference Section); distribution elsewhere uncertain; that indicated by Straw, 1958, Figure 4, is as yet unconfirmed. (BGS Sheets 114, 115 and ?102 and ?128).
Parent Unit: Trent Valley Formation (TRVA)
Previous Name(s): Martin Terrace Deposits (-2330)
River And Glaciofluvial Sheet Deposits, Undivided (-4206)
Martin Member (-2948)
Tattershall Airfield Member (-2949)
Upper River Terrace Deposits (-3566)
Glaciofluvial Sheet Deposits (GFSD)
Older River Sand And Gravel (ORSG)
Glacial Sand And Gravel (GSG)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Martin, Lincolnshire. Straw, 1958; Brandon and Sumbler in Bowen, 1999. 
Reference Section  Tattershall Airfield gravel pit. Tattershal Airfield Member: Brandon and Sumbler in Bowen, 1999. 
Reference(s):
Bowen, D Q. 1999. A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, No. 23. 
Brandon, A and Sumbler M G. Unpublished manuscript. 
Pocock, T I. 1929, The Trent valley in the glacial period. Zeitschrift fur Gletscherkunde, Vol.17. 302-318. 
Brandon A and Sumbler, M G. 1991. The Balderton Sand and Gravel: pre-Ipswichian cold stage fluvial deposits near Lincoln, England. Journal of Quaternary Science, Vol.6. 117-138. 
Straw, A. 1958. The glacial sequence in Lincolnshire. East Midlands Geographer, Vol.2, 29-40. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E114 E115