| Computer Code: |
LTH |
Preferred Map Code: |
LTH |
| Status Code: |
Full |
| Age range: |
Pleistocene Epoch (QP)
— Pleistocene Epoch (QP) |
| Lithological Description: |
Pebbly sand and sandy gravel with a high proportion (commonly 50% or more) of rounded quartzose pebbles (quartz, quartzite and sandstone).Quartzose gravel and sand - [Generic description: 1:50 k map margins]. |
| Definition of Lower Boundary: |
Unconformable on Lower Chalk. |
| Definition of Upper Boundary: |
Mostly found at surface. Overlain in part by (Anglian) chalky till. |
| Thickness: |
3.55m proven in borehole TL23NW/113 (TL 2048 3540). May be up to 5m elsewhere. |
| Geographical Limits: |
Capping hill top above c.65m OD around Fairfield Hospital, near Letchworth, with smaller spreads along the Pix Brook and to the southwest of Lower Wilbury Farm. Possibly underlying till-covered ground, south of the Hospital. |
| Parent Unit: |
Dunwich Group (DUNW)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Hill top at Fairfield Hospital, particularly open farmland to north. |
| Reference Section |
(Hand-Auger Hole) TL23NW/113. 100m northeast of church at Fairfield Hospital. |
| Reference(s): |
| none recorded or not applicable |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E221
|
