| Computer Code: |
ITCH |
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 brown organic silty clay, together with peaty clay and peat, overlying sand and gravel. Tufa occurs as 1 to 2m-high raised hummocky spreads. The surviving river terrace deposits comprise sand and gravel, planar bedded or cross-bedded, locally overlain by overbank deposits of clayey and sandy silts and silty clays. These fine-grained deposits may be partly aeolian in origin. The major gravel lithology is flint, dominantly sub-rounded to sub-angular and a little well-rounded, and subordinate quartz, ironstone and "sarson". The sand fraction is composed of fine- to coarse-grained well-rounded quartz grains, with subangular flint in the coarse fraction. The older, higher terraces are commonly cryoturbated. |
| Definition of Lower Boundary: |
Unconformable on Palaeogene and Cretaceous bedrock. |
| Definition of Upper Boundary: |
Surface. |
| Thickness: |
To c.12m |
| Geographical Limits: |
The catchment of the River Itchen and its tributaries in the Southampton-Alresford area. |
| 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 valley of the River Itchen and its tributaries in the Southampton-Alresford area. Edwards and Freshney, 1987. |
| Reference(s): |
| Farrant, A R. 2002. Geology of the Alreford district - a brief explanation of the geological map. Sheet explanation of the British Geological Survey. 1:50 000 sheet 300 Alresford (England and Wales). 30pp. |
| Booth, K A. 2002. Geology of the Winchester District - a brief explanation of the geological map. Sheet Explanation of the British Geological Survey. 1:50 000 Sheet 299, Winchester (England and Wales). |
| Edwards, R A, and Freshney, E C. 1987. Geology of the country around Southampton. Memoir of the British Geological Survey, Sheet 315 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E299
E300
E315
|
