| Computer Code: |
SUCA |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Mid Pleistocene (QPM)
— Holocene Epoch (QH) |
| Lithological Description: |
The Suffolk Catchments Subgroup encompasses all the fluvial, lacustrine and organic deposits of the rivers of Suffolk and Essex which flow into the North Sea south of the River Yare and north of the River Thames. Floodplain alluvium comprises soft silts and clays, commonly with beds of peat and a basal bed of sand and gravel. River terrace deposits are largely sand and gravel. The gravels are dominantly composed of subrounded to angular flint, including large cobbles, also rounded pebbles of quartz and quartzite, northern British erratics of glacial derivation, and a little chalk. Marine deposits are included where they are intercalated in dominantly fluvial formations. |
| Definition of Lower Boundary: |
Formation of the Suffolk Catchment Subgroup rest unconformably upon glacial and periglacial deposits, and upon Crag Group, London Clay Formation and Chalk Group bedrock. |
| Definition of Upper Boundary: |
Surface. |
| Thickness: |
c.10m |
| Geographical Limits: |
Restricted to that area of Suffolk and Essex that lies between the catchments of the River Thames and the River Waveney and their tributaries, on BGS 1:50 000 Sheets 176, 189-191, 205-208, 222-225, 240-242, 259. |
| Parent Unit: |
Britannia Catchments Group (BCAT)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
The area covered by the valleys of the rivers of Suffolk and Essex that flow into the North Sea. |
| Reference(s): |
| McMillan, A A, Hamblin, R J O and Merritt, J W. 2005. An overview of the lithostratigraphical framework for the Quarternary and Neogene deposits of Great Britain (onshore). British Geological Survey Research Report RR/04/04. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
