| Computer Code: |
BOOC |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Cenomanian Age (KE)
— Cenomanian Age (KE) |
| Lithological Description: |
Clasts of very glauconitic shelly sandstone, up to cobble size, commonly with a phosphatic rind, together with phosphatised shells (bivalves and ammonites) in a matrix of sandy glauconitic chalk. The derived fauna is Latest Albian; the indigenous fauna is Early Cenomanian. |
| Definition of Lower Boundary: |
The lower boundary is unconformable, locally strongly erosive and burrowed, overlying the Shaftesbury Sandstone Member.The boundary is marked by the change from weakly glauconitic sandstone up into green strongly glauconitic sandy calcareous mudstone ("marl"). |
| Definition of Upper Boundary: |
The upper boundary is taken at the disconformable contact with a phosphatic pebble bed at the base of the Zig Zag Chalk Formation or the West Melbury Marly Chalk Formation (at the base of the Chalk Basement Bed of Kennedy, 1970). |
| Thickness: |
0 to 1m |
| Geographical Limits: |
Currently known for Dorset and Wiltshire over the Mid Dorset Swell. |
| Parent Unit: |
West Melbury Marly Chalk Formation (WMCH)
|
| Previous Name(s): |
Passage Beds [Obsolete Name and Code: Use BOOC, SGBK, CLGB, MCH, UND, YED, MYS]
(-3236)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
Bookham Farm. See Bristow, et al. (1995, p.104, Figure 48). |
| Reference(s): |
| Bristow, C R, Barton, C M, Freshney, E C, Wood, C J, Evans, D J, Cox, B M, Ivimey-Cook, H C, and Taylor, R T. 1995. Geology of the country around Shaftesbury. Memoir of the British Geological Survey, Sheet 313 (England and Wales). |
| Drummond, P U O. 1970. The Mid-Dorset Swell. Evidence of Albian-Cenomanian Movements in Wessex. Proceedings of the Geologists' Association, Vol.81, 679-714. |
| Jukes-Browne, A J and Hill, W. 1900. The Cretaceous Rocks of Britain. 1. Gault and Upper Greensand. Memoir of the Geological Survey of Great Britain. |
| White, H J O. 1923. The geology of the country south and west of Shaftesbury. Memoir of the Geological Survey of Great Britain, Sheet 313 (England and Wales). |
| Hopson, P M. 2005. A stratigraphical framework for the Upper Cretaceous Chalk of England and Scotland, with statements on the Chalk of Northern Ireland and the UK Offshore Sector. British Geological Survey Research Report RR/05/01 102pp. ISBN 0 852725175 |
| Kennedy, W J. 1970. A correlation of the uppermost Albian and the Cenomanian of South-West England. Proceedings of the Geologists' Association, Vol.81, 613-677. |
| Jukes-Browne, A J and Hill, W. 1903 The Cretaceous Rocks of Britain, Vol.2. The Lower and Middle Chalk of England. Memoir of the Geological Survey of Great Britain. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
