| Computer Code: |
SHEN |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Albian Age (KA)
— Albian Age (KA) |
| Lithological Description: |
Lenticular beds of a pale brown, phosphatic limestone with scattered polished goethite ooliths (Owen 1972; Smart, 1997). It may be slightly limonitic and glauconitic. Brachiopods common. |
| Definition of Lower Boundary: |
The base is taken where a thin, gritty ironstone ("carstone") overlying silty beds at the top of the Woburn Sands Formation passes up into a sandy mudstone associated with lenticular beds of a pale brown phosphatic limestone with scattered polished goethite ooliths (Shenley Limestone Member) (Owen, 1972; Smart, 1997). |
| Definition of Upper Boundary: |
The top is taken where phosphatic limestone of the Shenley Limestone Member is overlain by a 1.2m-thick fissile, red mudstone informally called "Red Clay" or the "Cirripede Bed" of the Gault Formation. |
| Thickness: |
Up to c. 0.1m. |
| Geographical Limits: |
Restricted to the area around Leighton Buzzard. Leighton Buzzard Sheet 1:50k sheet number 220. |
| Parent Unit: |
Munday's Hill Phosphatic Sandstone Formation (MHPS)
|
| Previous Name(s): |
Shenley Limestone Bed
(-521)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Reference Section |
Bryants Lane Quarry, north of Leighton Buzzard. Shephard Thorne et al., 1994. |
| Type Area |
Shenley Hill [SP 93 27] near Leighton Buzzard. |
| Reference Section |
Munday's Hill, 420m northwest of Mile Tree Farm, Heath and Reach. Owen, 1972. |
| Reference(s): |
| Shepard-Thorn, E R, Moorlock, B S P, Cox, B M, Allsop, J M and Wood, C J. 1994. Geology of the country around Leighton Buzzard. Memoir of the British Geological Survey, Sheet 220 (England and Wales). |
| Eyers, J. 1991. The influence of tectonics on early Cretaceous sedimentation in Bedfordshire, England. Journal of the Geological Society of London, Vol. 149, 405-414. |
| Lamplugh, G W, and Walker, J F. 1903. On a fossiliferous band at the top of the Lower Greensand near Leighton Buzzard (Bedfordshire). Quarterly Journal of the Geological Society, London, Vol. 59, 234-265. |
| Casey, R, 1961. The stratigraphical palaeontology of the Lower Greensand. Palaeontology, Vol.3, 487-621. |
| Lamplugh, G W. 1922. On the junction of the Gault and Lower Greensand near Leighton Buzzard, Bedfordshire. Quarterly Journal of the Geological Society of London, Vol. 78, 1-81. |
| Owen, H G. 1972. The Gault and its junction with the Woburn Sands in the Leighton Buzzard area, Bedfordshire and Buckinghamshire. Proceedings of the Geologists' Association, Vol.83, 287-312. |
| Eyers, J. 1995. Correlation of the Lower Greensand Group (Woburn Sands and Carstone) of the Bedfordshire Province, England. Cretaceous Research, Vol.16, 385-413. |
| Smart, P J. 1997. The basal Gault and Gault-Woburn Sands junction beds in Chamberlain's Barn Quarry, Leighton Buzzard, Bedfordshire, England. Proceedings of the Geologists' Association, Vol.108, 287-292. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
