| Computer Code: |
CHRM |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Ypresian Age (GY)
— Ypresian Age (GY) |
| Lithological Description: |
Fine-grained, silty, commonly glauconitic and micaceous sand, interbedded with yellowish brown, often carbonaceous, colour-banded and laminated sand and silt. Palaeosols with or without rootlets are common. |
| Definition of Lower Boundary: |
Sharp contact on uniform, bioturbated, shelly clays of the London Clay Formation. In King (in press) the basal boundary is amended down to the depth of 243.9m in the Christchurch Borehole [SZ 2002 9301]. King (in press) places the lower boundary at the base of a prominent rounded-pebble bed at a major basin-wide erosion surface and contends that the underlying very fine-grained glauconitic sand can be correlated with Unit B of the London Clay Formation. |
| Definition of Upper Boundary: |
Sharp, erosive contact with sands of the overlying Poole Formation. |
| Thickness: |
0-75m. 53m in the Christchurch Borehole SZ29SW12 [SZ 2002 9301]. |
| Geographical Limits: |
East Dorset and West Hampshire. |
| Parent Unit: |
London Clay Formation (LC)
|
| Previous Name(s): |
none recorded or not applicable
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Christchurch Borehole, Christchurch. Bristow et al. (1991). |
| Reference(s): |
| King, C. In press. A correlation of Tertiary rocks in the British Isle and adjacent areas. Special Report of the Geological Society of London, No.12. |
| Bristow, C R, Freshney, E C, and Penn, I E. 1991. Geology of the country around Bournemouth. Memoir for 1:50 000 geological sheet 329 (England and Wales). HMSO, London. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E329
|
