Computer Code: |
ALSG |
Preferred Map Code: |
symb |
Status Code: |
Pending Upgrade |
Age range: |
Devensian Stage (QD)
— Devensian Stage (QD) |
Lithological Description: |
Sand and gravel with minor clay and silt lenses, commonly including deposits of head, both capping the terrace deposits and involuted with them. |
Definition of Lower Boundary: |
The bedrock surface - commonly cryogenically involuted; other deposits may intervene. |
Definition of Upper Boundary: |
Top of sand and gravel, commonly corresponding to terrace surface; commonly overlain by head that is involuted with sand and gravel to varying degrees. |
Thickness: |
Typically to 4m |
Geographical Limits: |
Derwent Valley. |
Parent Unit: |
Trent Valley Formation (TRVA)
|
Previous Name(s): |
Beeston Terrace [Obsolete Name and Code: Use BSSG, ALSG]
(-2562)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
none recorded or not applicable |
Reference(s): |
Brandon, A. 1996. Geology of the Lower Derwent Valley: 1:10 000 Sheets SK33SE, SK43SW and SK43SE. British Geological Survey Technical Report WA/96/07. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
none recorded or not applicable |