The BGS Lexicon of Named Rock Units — Result Details

Reading Formation

Computer Code: RB Preferred Map Code: RB
Status Code: Full
Age range: Paleocene Epoch (GP) — Paleocene Epoch (GP)
Lithological Description: Dominantly clay, mottled by pedogenetic processes in a humid environment (Buurman, 1980). Red hues dominate with a more or less equal proportion of blue-grey and brown. Red sediments decrease towards the east where there were shorter periods of subaerial weathering, and reducing conditions in ephemeral lagoons. The proportion of sand beds varies greatly, and may constitute more than half the formation, dominantly in the basal part (eg Crane and Goldring, 1991).
Definition of Lower Boundary: London Basin: the base is generally well defined although may be diffuse due to the translocation of clay into the underlying sand of the Upnor Formation during pedogenesis. In the Hampshire Basin, the Reading Formation rests unconformably on chalk.
Definition of Upper Boundary: The top is sharp, at an upward change from mottled clay to glauconitic sands and sandy clays of the Harwich Formation.
Thickness: Maximum 27m, generally 12 to 16m; in two leaves in Central London.
Geographical Limits: Not defined.
Parent Unit: Lambeth Group (LMBE)
Previous Name(s): Reading Beds (-480)
Reading Formation [Obsolete/Duplicate Code: Use RB] (REA)
Mottled Clay (Reading Formation) (MCL)
Alternative Name(s): none recorded or not applicable
Type Section  Warner's Brickworks, Knowl Hill, Reading 
Reference Section  Jubilee Extension Borehole 404T. BGS registration number TQ37NW/2118. 
Crane, P R and Goldring, R, 1991. The Reading Formation (late Palaeocene to early Eocene) at Cold Ash and Pincent's Kiln (Berkshire) in the western London Basin. Tertiary Research, Vol.12, 147-158. 
Ellison, R A, Knox R W O'B, Jolley, D W and King, C, 1994. A revision of the lithostratigraphical classification of the early Palaeogene strata of the London Basin and East Anglia. Proceedings of the Geologists' Association, Vol.105, 187-197. 
Edwards, R A and Freshney, E C. 1987. Lithostratigraphical classification of the Hampshire Basin Palaeogene Deposits (Reading Formation to Headon Formation) Tertiary Research, Vol.8, 43-73. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E314 E206 E207 E239 E254 E255 E256 E257 E266 E268 E267 E269 E282 E283 E284