The BGS Lexicon of Named Rock Units — Result Details

Roxham Sand Member

Computer Code: RXB Preferred Map Code: RxB
Status Code: Full
Age range: Tithonian Age (JI) — Tithonian Age (JI)
Lithological Description: Grey and yellow-green, pyritic, silty sands with an indurated basal pebbly sandstone with black chert phosphatic nodules and derived Kimmeridgian debris. Bioturbation and burrows occur in the unit and may extend down into the top of the underlying Kimmeridge Clay.
Definition of Lower Boundary: A down-section change from sands, with a pebbly base, to mudstones (Kimmeridge Clay Formation). An erosion surface separates the two units.
Definition of Upper Boundary: Green, glauconitic, clayey sands with abundant phosphatic nodules (Runcton Sand Member) overlies grey and yellow-green, pyritic, silty sands (Roxham Sand Member).
Thickness: Up to 6m.
Geographical Limits: The member crops out between the banks of the Babingley River, southwards to near Southery, where it disappears beneath the Methwold Fens. It has been penetrated by a number of boreholes at Hunstanton, North Wootton, Gayton, Mundford and Little Ouse. The member extends under The Wash and has been recognised in borehole 72/77B, but passes laterally into the lower pat of the Spilsby Sandstone Formation.
Parent Unit: Sandringham Sand Formation (SAS)
Previous Name(s): Roxham Beds (-1157)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  BGS Wash Borehole 72/77B. Wingfield et al., 1978; Gallois, 1994. 
Reference Section  Marham Borehole. Gallois, 1994. 
Type Section  Pratt's Bridge, Roxham Farm, West Dereham. Casey & Gallois, 1973. 
Reference Section  Hunstanton Borehole. Gallois, 1994. 
Reference Section  Gayton Borehole. Gallois, 1994. 
Reference(s):
Casey, R and Gallois, R W. 1973. The Sandringham Sands of Norfolk. Proceedings of the Yorkshire Geological Society, Vol.41, 1-22. 
Casey, R 1973. The ammonite succession at the Jurassic-Cretaceous boundary in Eastern England. In Casey, R and Rawson, P F [editors], The Boreal Lower Cretaceous [Liverpool: Seel House Press.] 
Gallois, R W, 1994. The geology of the country around King's Lynn and The Wash. Memoir of the British Geological Survey, Sheet 145 and part of 129 (England and Wales). 
Wingfield, R T R, Evans, C D R, Deegan, S E and Floyd, R. 1978. Geological and geophysical survey of The Wash. Report of the Institute of Geological Sciences, 78/18, 32pp. 
Gallois, R W. 1984. The Late Jurassic to Mid Cretaceous rocks of Norfolk. Bulletin of the Geological Society of Norfolk, Vol.34, 3-64. 
Whitaker, W and Jukes-Browne, A J. 1899. The geology of the borders around The Wash: including Boston and Hunstanton. Memoir of the Geological Survey of England and Wales. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E159 E173