The BGS Lexicon of Named Rock Units — Result Details

Thames Group

Computer Code: THAM Preferred Map Code: TGp
Status Code: Full
Age range: Eocene Epoch (GE) — Eocene Epoch (GE)
Lithological Description: Silty clay/mudstone, sandy silts and sandy clayey silts of marine origin.
Definition of Lower Boundary: In both the Hampshire and London Basins the boundary is placed at the erosion surface below the glauconitic sands and sandy clays of the Oldhaven Formation of King (1981), which rest on the Woolwich and Reading Beds (King, 1981), or the Lambeth Group (Ellison et al, 1994).
Definition of Upper Boundary: In the Hampshire Basin the boundary is placed at the erosion surface at the base of the Wittering Formation of the Bracklesham Group, where the dark grey bioturbated silty clay of the London Clay gives way upwards to the glauconitic sands and silty clays of the Wittering Formation.
Thickness: c.110-115m in the Hampshire Basin.
Geographical Limits: Eastern Hampshire Basin.
Parent Unit: Not Applicable (-)
Previous Name(s): London Clay Group (-1227)
Alternative Name(s): none recorded or not applicable
Reference Section  Seacliffs at Whitecliff Bay, Isle of Wight. 
Partial Type Section  Foreshore between Bognor Regis and Pagham Harbours 
King, C, 1981. The stratigraphy of the London Clay and associated deposits. Tertiary Research Special Paper No.6. (Backhuys: Rotterdam). 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E132 E148 E176 E191