The BGS Lexicon of Named Rock Units — Result Details

Ribble Sandstone Member

Computer Code: RISA Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Kimmeridgian Age (JD) — Tithonian Age (JI)
Lithological Description: The member comprises thick-bedded, structureless, medium-grained, poorly to well sorted sandstones. It lacks bioturbation. Composition is sub-arkosic. The sandstones contain clay clasts and thinly interbedded laminated, fissile mudstones.
Definition of Lower Boundary: The base is defined by a sharp, down-section change from sandstones to dark grey, fissile mudstones (Kimmeridge Clay). The boundary is marked by a sharp, down-section increase in gamma-ray values and a sharp increase in velocity.
Definition of Upper Boundary: The top is defined by a sharp, down-section change from dark grey, fissile mudstones (Kimmeridge Clay) to sandstones. A down-section decrease in gamma-ray values and a sharp or transitional down-section decrease in velocity coinsides with the boundary.
Thickness: Up to 55 m thick.
Geographical Limits: The Ribble Sandstone Member is confined to the Fulmar Field (Quadrant 30/16) in the Central Graben.
Parent Unit: Kimmeridge Clay Formation (KC)
Previous Name(s): Ribble Unit (-5173)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  North Sea well 30/16-7 between 3262 and 3305 m below KB (Richards et al., 1993). 
Reference Section  North Sea well 30/16-25 between depths 3087.5 and 3115 m (Richards et al., 1993). 
Reference(s):
Johnson, H D, Mackay, T A and Stewart, D J. 1986. The Fulmar Oilfield (Central North Sea): geological aspects of its discovery, appraisal and development. Marine & Petroleum Geology, 3, 99-125. 
Mehenni, M and Roodenburg, W Y. 1990. Fulmar Field- UK: South Central Graben, North Sea. In: Beaumont, E A and Foster, N H (eds.) Structural traps IV. Tectonic and non-tectonic fold traps. 113-139. [American Association of Petroleum Geologists, Tulsa] 
Stockbridge, C P and Grey, D I. 1991. The Fulmar Field, Blocks 30/16 and 30/11b, UK North Sea. In: Abbotts, I L (ed.) United Kingdom oil and gas fields, 25 years commemorative volume. Memoir of the Geological Society, London, 14, 309-316. 
Richards, P C, Lott, G K, Johnson, H, Knox, R W O'B. and Riding, J B. 1993. 3. Jurassic of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G. Lithostratigraphic nomenclature of the UK North Sea. [British Geological Survey, Nottingham] 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable