| Computer Code: |
TCRS |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Aptian Age (KP)
— Aptian Age (KP) |
| Lithological Description: |
Dark blue well-packed sandstone (Bed 13), overlain by harder brown sandstone (Bed 14) with seams of phosphatic nodules near the base and top of the member. Both contain a single discontinuous seam of large, fossiliferous "doggers". |
| Definition of Lower Boundary: |
Boundary placed at the upward conformable change from dark blue argillaceous sandstone of Simpson (1985) Bed 12 of the Lower Lobster Member into the dark blue well-packed sandstone of Simpson (1985) Bed 13 of The Crackers Member. This boundary is gradational. |
| Definition of Upper Boundary: |
Boundary placed at the conformable upward change from hard brown sandstone (Bed 14) of The Crackers Member into sporadically glauconitic brown sandy mudstone (Bed 15) of the Upper Lobster Member. |
| Thickness: |
6.0m at the type site. |
| Geographical Limits: |
Isle of Wight and Dorset with equivalent beds in the Weald. |
| Parent Unit: |
Atherfield Clay Formation (AC)
|
| Previous Name(s): |
Crackers Group [Obsolete Name and Code: Use ULOB, TCRS]
(-2478)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
The coastal cliff section at Red Cliff, Sandown [SZ 626 855]. Showing a full succession but generally obscured by landslide debris. |
| Reference Section |
The coastal cliff section at Compton Bay [SZ 372 848], Isle of Wight. Generally showing a full succession. |
| Type Section |
Defined as the coastal cliff section of Chale Bay, Isle of Wight between Shepherd's Chine [SZ 4466 7982] and Whale Chine [SZ 4684 7825]. |
| Reference(s): |
| Fitton, W H. 1847. A stratigraphical account of the section from Atherfield to Rocken-end on the south-west coast of the Isle of Wight. Quarterly Journal of the Geological Society of London, Vol.3, 289-327. |
| Osborne White, H J. 1921 [1994 reprint]. A short account of the geology of the Isle of Wight. Memoirs of the Geological Survey of Great Britain. 235pp. [HMSO.] |
| Simpson, M I. 1985. The stratigraphy of the Atherfield Clay Formation (Lower Aptian, Lower Cretaceous) at the type and other localities in southern England. Proceedings of the Geologists' Association, Vol.96(1), 23-45. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
