The BGS Lexicon of Named Rock Units — Result Details

Upper Spilsby Sandstone Member

Computer Code: USPS Preferred Map Code: USpS
Status Code: Pending Upgrade
Age range: Berriasian Age (KR) — Valanginian Age (KV)
Lithological Description: Upper Spilsby Sandstone. Thin, coarse-grained, grey or brown pebbly sandstone with iron ooliths (Ferruginous Grit of Swinnerton, 1937), underlain by fine-to medium-grained, buff, yellow and white sands with sparse calcareous "doggers" (the upper part of Swinnerton's, 1937, "Glauconitic Sands"). The latter sands become coarser and greener towards the base of the member. A bed of phosphatic nodules and small (generally chert) pebbles occurs at the base (the Mid Spilsby Nodule Bed of Casey, 1963, 1973). Offshore, in the Southern North Sea, the Upper Spilsby Sandstone has not been recognised.
Definition of Lower Boundary: The base is taken where coarse-grained, pebbly, glauconitic sands and sandstones with calcareous "doggers" and sporadic phosphatic nodules towards the top (Lower Spilsby Sandstone) are overlain by medium-grained, buff and green sands with sparse calcareous "doggers" and a basal bed of phosphatic nodules and small (generally chert) pebbles of the Upper Spilsby Sandstone. An erosion surface separates the two units.
Definition of Upper Boundary: The upper boundary is taken at the up-section change from pale yellow, medium-grained sand and sandstone (Upper Spilsby Sandstone) into the purple-grey and brown mottled mudstones with sporadic iron ooliths of the Hundleby Clay Member, Claxby Ironstone Formation or argillaceous oolitic ironstone of the Claxby Ironstone Formation.
Thickness: To c.11.5m.
Geographical Limits: See Spilsby Sandstone Formation.
Parent Unit: Spilsby Sandstone Formation (SYS)
Previous Name(s): Glauconitic sands [in part] and ferruginous grit [Obsolete Name and Code: Use USPS] (-2519)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Railway cutting between Benniworth and Donnington-on-Bain. Casey, 1973. 
Reference Section  Fordington Borehole TF47SW24, 8km north of Spilsby (Boston Corporation Waterworks). Swinnerton, 1935, embedded Casey, 1973. 
Reference(s):
Swinnerton, H H. 1935. The rocks below the Red Chalk of Lincolnshire and their cephlopod fauna. Quarterly Journal of the Geological Society, London, 91, 1-46. 
Swinnerton, H H. 1937 (for 1936). A monograph of British Cretaceous Belemnites, Part 11. Monograph of the Palaeontographical Society. 
Casey, R. 1963. The dawn of the Cretaceous period in Britain. Bulletin of the South East Union of Scientific Societies, 117, 1-15. 
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.] 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable