| Computer Code: |
S205 |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Early Pleistocene (QPE)
— Mid Pleistocene (QPM) |
| Lithological Description: |
Cross-bedded and massive, moderately sorted sand and gravel. |
| Definition of Lower Boundary: |
Unconformable on bedrock. |
| Definition of Upper Boundary: |
Overlain by mid-Pleistocene glacigenic deposits. Upper boundary may be difficult to determine where overlain by glaciofluvial sand and gravel, but the presence of more angular clasts, chalk, and poorer sorting in the latter is usually helpful. |
| Thickness: |
5 to 10 m thick. |
| Geographical Limits: |
Valley of the Ancestral Thames, East Anglia. |
| Parent Unit: |
Sudbury Formation (SBRY)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| none recorded or not applicable |
| Reference(s): |
| Gibbard, P L. 1985. Pleistocene history of the Middle Thames Valley. (London: Cambridge University Press.) |
| Hey, R W. 1965. Highly quartzose pebble gravels in the London Basin. Proceedings of the Geologists’Association, Vol. 76, 403-420. |
| Hey, R W. 1980. Equivalents of the Westland Green Gravels in Essex and East Anglia. Proceedings of the Geologists’ Association, Vol. 91, 279-290. |
| Whiteman, C A and Rose, J. 1992. Thames river sediments of the British Early and Middle Pleistocene. Quarterly Science Reviews, Vol.11, 363-375. |
| Whiteman, C A. 1992. The palaeogeography and correlation of pre-Anglian-Glaciation terraces of the River Thames in Essex and the London Basin. Proceedings of the Geologists' Association, Vol.103, 37-56. |
| McMillan, A A, Hamblin, R J O, and Merritt, J W. 2011. A lithostratigraphical framework for onshore Quaternary and Neogene (Tertiary) superficial deposits of Great Britain and the Isle of Man. British Geological Survey Research Report, RR/10/03. 343pp. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
