| Computer Code: |
FHAM |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Quaternary Period (Q)
— Quaternary Period (Q) |
| Lithological Description: |
Sand and gravel with beds of clayey, sandy and pebbly silt. A borehole at [TL 8504 6747] (BGS Registered No. TL86NE/101) proved 5.6 m of the member including 2.1 m of clayey, sandy, pebbly silt. Mean grading figures show 23 per cent fines, 71 per cent sand and 6 per cent gravel. |
| Definition of Lower Boundary: |
Generally unconformably overlies Chalk bedrock, but locally for example in the vicinity of Kentford they overlie glacial silt. |
| Definition of Upper Boundary: |
At surface. |
| Thickness: |
Generally up to about 4 m but a borehole at [TL 8504 6747] proved 5.6 m. BGS Borehole Registration No. TL86NE/101. |
| Geographical Limits: |
Within the Kennett valley (tributary of the Lark) around Kentford and Fornham and upstream as far as Moulton. |
| Parent Unit: |
Lark Valley Formation (LKVY)
|
| Previous Name(s): |
4th Terrace of River Lark (Clayton, 1983) [Obsolete Name and Code: Use FHAM]
(-247)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
The stratotype is an area adjacent to the River Kennett around Kentford, Suffolk which has been largely worked out (Bristow, 1990). |
| Reference(s): |
| Bristow, C R. 1990. Geology of the country around Bury St Edmunds. Memoir of the British Geological Survey, Sheet 189 (England and Wales). |
| Bowen, D Q. 1999. A revised correlation of Quaternary deposits in the British Isles. Geological Society Special Report, No. 23. |
| Clayton, A R. 1983. The sand and gravel resources of the country between Maidenhall and Barrow, Suffolk: description of 1:25000 Sheets TL76, TL77 and part of TL87. Mineral Assessment Report, 123, Institute of Geological Sciences, London. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E189
|
