The BGS Lexicon of Named Rock Units — Result Details

Fittleworth Member

Computer Code: FIB Preferred Map Code: FiB
Status Code: Full
Age range: Aptian Age (KP) — Aptian Age (KP)
Lithological Description: Glauconitic sandy clays and clayey sands: orange-brown where weathered; bright green where unweathered.
Definition of Lower Boundary: The lower boundary is marked by the incoming of conspicuous glauconitic clayey sands and sandy clays on fine-grained to medium-grained "Bargate Beds" (now Easebourne Member) where present.
Definition of Upper Boundary: In the area from Stedham to Storrington the upper boundary is marked by the change from glauconitic sandy clay and clayey sand upwards into fine-grained well-sorted sands of the Pulborough Sandrock. From Storrington eastwards the boundary is diffuse at the upward passage into silty clay of the Marehill Clay Member.
Thickness: 10 to 60m.
Geographical Limits: From Stedham, West Sussex [SU 86 22] (where the combined Fittleworth Member and Selham Ironshot Sands Member are replaced by the Rogate Member) and probably eastwards to Heath Common [TQ 11 14]. From about 9 km from Stedham, West Sussex [SU 86 22] to east of Selham, West Sussex [SU 94 20] the Fittleworth Member is divided by the Selham Ironshot Member. Samuel (1994) proposed the name "Upper Fittleworth Beds" for the upper division (c.2m thick). This is re-named informally the "upper Fittleworth Member", with the lower division (to c.8m) named the "lower Fittleworth Member".
Parent Unit: Sandgate Formation (SAB)
Previous Name(s): Fittleworth Beds (-249)
Alternative Name(s): none recorded or not applicable
Reference Section  Hoes Farm Borehole SU91NE/19 gives a basal section. "The only detailed, albeit incomplete, section in this member is provided by the Hoes Farm Borehole [SU9808 1962] (Bristow et al., 1987). There, 18.35m of friable glauconitic, silty, fine-grained sandstone rests on a similar sandstone, 4.3m thick, with a rich and varied "Bargate-type" fauna. At the base of the latter sandstone, a 0.3m bed of sandy limestone overlies 0.4m of dark grey siltstone, which in turn rests on an eroded surface of the Hythe Formation." (Aldiss, 2002). 
Partial Type Section  A former brickpit at Fittleworth village. Current state not known but see Aldiss (2002). 
Young, B and Lake, R D. 1988. Geology of the country around Brighton and Worthing. Memoir of the British Geological Survey, Sheet 318 and 333 (England and Wales). 
Bristow, C R and Wyatt, R J. 1983. Geological notes and local details for 1:10 000 sheets TQ01NW, NE, SW and SE (Pulborough and Storrington). British Geological Survey Technical Report, WA/VG/83/03. 
Bristow, C R, Morter, A A and Wilkinson, I P. 1987. The stratigraphy and palaeontolgy of the Lower Greensand of the Hoes Farm Borehole, near Petworth, Sussex. Proceedings of the Geologists' Association, Vol.98(3), 217-227. 
Aldiss, D T. 2002. Geology of the Chichester and Bognor district. Sheet Explanation of the British Geological Survey, 1:50 000 Series Sheet 317 and Sheet 332 (England and Wales). 
Samuel, M D A. 1994. Geological notes and local details for 1:10,000 sheets SU82SE, SU92SW and SU92SE (Midhurst, Lodsworth and Petsworth). British Geological Survey Technical Report, WA/94/28. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E317 E318 E332 E333