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: | Mid Pleistocene (QPM) — Mid Pleistocene (QPM) | ||
| 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. +18 m in the Type Area, i.e. about 16 m above the Witham Floodplain there. Correlated with the Eagle Moor Sand and Gravel west of the Lincoln Gap. Middle Pleistocene (MI Stage 12 or 10). | ||
| 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. 7 m | ||
| 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): | River and Glaciofluvial Sheet Deposits, Undivided
(-4206)
Martin Member [Obsolete Name and Code: Use MTNSG] (-2948) Tattershall Airfield Member [Obsolete Name and Code: Use MTNSG] (-2949) Glacial sand and gravel [Obsolete Name and Code] (GSG) Martin Terrace Deposits [Obsolete Name and Code: Use MTNSG] (-2330) Glaciofluvial sheet deposits (GFSD) Older river sand and gravel (ORSG) Upper River Terrace Deposits [Obsolete Name and Code: Use MTNSG] (-3566) Glaciofluvial sheet deposits (GFSD) Older river sand and gravel (ORSG) |
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| 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): | |||
| Brandon, A, and Sumbler M G. Unpublished manuscript.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. | |||
| Bowen, D Q. 1999. A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, No. 23. | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E114 E115 | |||