| Computer Code: |
HAAV |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Early Pleistocene (QPE)
— Holocene Epoch (QH) |
| Lithological Description: |
Floodplain alluvium and river terrace deposits. The floodplain alluvium comprises overbank deposits of mottled dark grey and orange organic silt, silty clay and clayey sand, tgether with peat, overlying sand and gravel. Fourteen river terraces are preserved. The river terrace deposits comprise very sandy gravels. The clasts are sub-angular to sub-rounded, poorly sorted up to 5cm in diameter, dominantly flint, with a little Upper Greensand chert, "sarsen" stone, vein quartz, Jurassic limestone, and well-rounded flints from the Palaeogene, in a matrix of clayey sand. Deposits of the higher terraces are cryoturbated. |
| Definition of Lower Boundary: |
The fluvial deposits rest unconformably on Palaeogene and Cretaceous strata. |
| Definition of Upper Boundary: |
Surface. |
| Thickness: |
To 8m, including up to 4m of alluvial overbank deposits. |
| Geographical Limits: |
The catchment of the Hampshire Avon and its tributaries. |
| Parent Unit: |
Solent Catchments Subgroup (SNTCA)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
The valleys of the Hampshire Avon and its tributaries from Christchurch to Warminster and Devizes. Bristow et al., 1991. |
| Reference(s): |
| Bristow, C R, Freshney, E C, and Penn, I E. 1991. Geology of the country around Bournemouth. Memoir for 1:50 000 geological sheet 329 (England and Wales). HMSO, London. |
| Clarke, M R. 1981. The sand and gravel resources of the country north of Bournemouth, Dorset. Description of parts of 1:25000 Sheets SU00, 10, 20, SZ09, 19 and 29. Mineral Assessment Report of the Institute of Geological Sciences, 51. |
| Reid, C. 1902. The geology of the country around Ringwood. Memoir of the Geological Survey of Great Britain, Sheet 314 (England and Wales). |
| White, H J O. 1917. Geology of the country around Bournemouth (2nd edition). Memoir of the Geological Survey of Great Britain, Sheet 329 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E266
E281
E282
E283
E297
E298
E314
E329
|
