The BGS Lexicon of Named Rock Units — Result Details
Pershore Sand and Gravel Member
| Computer Code: | PERT | 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 Avon Fifth Terrace of Tomlinson (1925) and of BGS Maps (sheets 199, 200 and 216). Dominated by clasts of 'Bunter' quartz/quartzite lithologies with subordinate flint. Terrace surface some 40 m above modern Avon alluvial floodplain at type locality, where it includes the organic Allesborough Bed (the Pershore Fossil Bed of Maddy at al., 1991) at base, which is assigned to MIS 9. Probably equates with Frog Hall Member of the upstream Avon/Leam, and with Bushley Green Member of the Severn Valley Formation. River terrace deposits. Mid Pleistocene (MI Stage 9 to 8). | ||
| Definition of Lower Boundary: | Unconformable, commonly channelled base on Lower Jurassic or Triassic bedrock. | ||
| Definition of Upper Boundary: | Ground surface. | ||
| Thickness: | 0 to c. 7 m. | ||
| Geographical Limits: | Lower Avon valley, Stratford-upon-Avon to Tewkesbury. (BGS Sheets 199, 200, 216). | ||
| Parent Unit: | Warwickshire Avon Valley Formation (AVON) | ||
| Previous Name(s): | Fifth or Pershore Terrace [Deposits] [Obsolete Name and Code: Use PERT]
(-2973)
No 5 Terrace [Deposits] [Obsolete Name and Code: Use PERT] (-3609) Avon Fifth Terrace [Deposits] [Obsolete Name and Code: Use PERT] (-2366) Pershore Member [Obsolete Name and Code: Use PERT] (-446) Pershore Terrace Deposits (Warwickshire Avon) [Obsolete Name and Code: Use PERT] (-447) Fifth Terrace [Deposits] [Obsolete Name and Code: Use PERT] (-4250) |
||
| Alternative Name(s): | none recorded or not applicable | ||
| Stratotypes: | |||
| Type Section | Allesborough Hill road cutting, near Pershore, Warwickshire. Whitehead, 1989 (in which the NGR of the site is wrongly quoted as SO 038 464). | ||
| Reference(s): | |||
| Bowen, D Q. 1999. A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, No. 23. | |||
| Barclay, W J, Ambrose K, Chadwick, R A, and Pharaoh, T C. 1997. Geology of the country around Worcester. Memoir of the British Geological Survey, Sheet 199 (England and Wales). | |||
| Tomlinson, M E. 1925. The river terraces of the lower valley of the Warwickshire Avon. Quarterley Journal of the Geological Society of London. Vol.81, 137-169. | |||
| Whitehead, P F. 1989. The development and sequence of deposition of the Avon Valley river terraces. 37-41 in Keen, D H, 1989. The Pleistocene of the West Midlands. Field Guide. [Cambridge: Quaternary Research Association.] | |||
| Stoker, M S, McMillan, A A and Waters, C N. Quaternary Stratigraphical Chart: Southern Britain. British Geological Survey, 1 poster. | |||
| Worssam, B C, Ellison, R A and Moorlock, B S P. 1989. Geology of the country around Tewkesbury. Memoir of the British Geological Survey, Sheet 216 (England and Wales). | |||
| Maddy, D, Keen, D H, Bridgland, D R and Green, C P. 1991. A revised model for the Pleistocene development of the River Avon, Warwickshire. Journal of the Geological Society of London, Vol.148, 473-484. | |||
| Williams, B J and Whittaker, A. 1974. Geology of the country around Stratford-upon-Avon and Evesham. Memoir of the Geological Survey of Great Britain Sheet 200 (England and Wales). | |||
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: | |||
| E199 E200 E216 | |||