| Computer Code: |
UTMS |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Anglian Stage (QA)
— Holocene Epoch (QH) |
| Lithological Description: |
Mainly sand and gravel forming river terraces and silt, silty clay and sand forming floodplains and concealing sand and gravel. Including units of silty sand, silt, clay and peat. Terrace deposits of the upper Thames contain clasts mainly of limestone lithologies. The formation includes interbedded units of locally fossiliferous silty sand, silt together with organic clay, tufa and peat, which are biostratigraphically correlated with interglacial (warm) stages. The main terrace deposit members are the Freeland Sand and Gravel, Spelsbury Gravel, Hanborough Gravel, Daylesford Sand and Gravel, Wolvercote Sand and Gravel, Summertown-Radley Sand and Gravel, Northmoor Sand and Gravel and Alluvium. In the Thame and Windrush valleys terrace deposit member include the Tiddington Sand and Gravel, Chilworth Sand and Gravel, Blackditch Sand and Gravel, Shabbington Sand and Gravel, Sherbourne Sand and Gravel, Ickford Sand and Gravel, Rissington Sand and Gravel and Quarrendon Sand and Gravel. |
| Definition of Lower Boundary: |
Unconformable on glacigenic deposits of the Anglian stage or older Pleistocene strata or bedrock. Individual terrace deposit members rest unconformably on older Pleistocene strata or bedrock. |
| Definition of Upper Boundary: |
Ground surface. |
| Thickness: |
Single terrace aggradations range from 3 to 12m. |
| Geographical Limits: |
The upper part of the valley of the River Thames, upstream of Goring together with deposits of tributary valleys including the Thame, Ock, Cherwell, Evenlode and Windrush. |
| Parent Unit: |
Thames Catchments Subgroup (THCAT)
|
| Previous Name(s): |
Upper Thames Valley Formation
(UTMS)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
The Upper Thames Valley Formation includes all of the mainstream terrace deposits and alluvium units of the valley of the River Thames upstream of the Groing Gap. Gibbard, in Bowen, 1999, 45-48. |
| Reference(s): |
| Ellison, R A, Woods, M A, Allen, D J, Forster, A, Pharaoh, T C and King, C. 2004. Geology of London. Memoir of the British Geological Survey, Sheets 256 (North London), 257 (Romford), 270 (South London), 271 (Dartford) (England and Wales). |
| Gibbard, P L. 1999. The Thames Valley, its tributaries and their former courses. 45-58 in Bowen, D Q (Editor), A revised correlation of Quaternary deposits in the British Isles. [London: The Geological Society.] |
| McMillan, A A, Hamblin, R J O and Merritt, J W. 2005. An overview of the lithostratigraphical framework for the Quarternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report RR/04/04. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E217
E201
E218
E235
E236
E237
E238
E239
E252
E253
|
