| Computer Code: |
CCG |
Preferred Map Code: |
CCG |
| Status Code: |
Full |
| Age range: |
Pliocene Epoch (NP)
— Gelasian Age (Q2G) |
| Lithological Description: |
Carbonate-rich skeletal sands. The acid-insoluble sand fraction is moderately- to poorly-sorted medium-grained sand, the mud content is low. Basal lag gravel rich in pebbles of phosphatic mudstone largely derived from the Thames Group. |
| Definition of Lower Boundary: |
Rests unconformably on the undulose, possibly tidally-scoured, surface of the Thames Group throughout its known distribution. |
| Definition of Upper Boundary: |
Overlain unconformably by rocks of the Norwich Crag Formation across most of its extent, but Red Crag Formation material is banked against a buried ridge of the Coralline Crag in some areas and thin Red Crag deposits overlie the Coralline Crag locally. |
| Thickness: |
c.25m maximum onshore. |
| Geographical Limits: |
Restricted to southeast Suffolk, around Orford and Aldeburgh, as far north as Thorpeness and just into the adjacent offshore area. There are isolated outliers at Ramsholt and Tattingstone. |
| Parent Unit: |
Crag Group (CRAG)
|
| Previous Name(s): |
Coralline Crag [Obsolete Name and Code: Use CCG]
(-3283)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Area |
Pits around Aldeburgh, Sulffolk. Balson et al., 1993. |
| Reference(s): |
| Balson, P S, Mathers, S J, and Zalasiewicz, J A. 1993. The lithostratigraphy of the Coralline Crag (Pliocene) of Suffolk. Proceedings of the Geologists' Association, Vol. 104, 59-70. |
| Balson, P S. 1989. Tertiary phosphorites in the southern North Sea Basin: origin, evolution and stratigraphic correlation, 51-70 in Herriet, J P, and de Moor, G (editors). The Quaternary and Tertiary geology of he Southern Bight, North Sea. Ministry of Economic Affairs, Belgium Geological Society. |
| Balson, P S. 1990. The Neogene of East Anglia - a field excursion report. Tertiary Research, Vol. 11, 179-189. |
| Balson, P S, and Cameron, T D J. 1985. Quaternary mapping offshore East Anglia. Modern Geology, Vol. 9, 221-239. |
| Moorlock, B S, Hamblin, R J O, Morigi, A N, Booth, S J and Jeffery, D H. 2000a. The geology of the country around Lowestoft and Saxmundham. Memoir of the British Geological Survey, sheets 176 and 191 (England and Wales). |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E208
E225
E191
E207
E224
E242
|
