The BGS Lexicon of Named Rock Units — Result Details

Leckenby Formation

Computer Code: LKNB Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Callovian Age (JC) — Callovian Age (JC)
Lithological Description: The formation comprises sandstones overlying thin mudstones with a thin, but persistent basal limestone bed. Sandstones are glauconitic and variably carbonate cemented.
Definition of Lower Boundary: The lower boundary is placed at the base of a thin limestone unit (coeval with the Cornbrash) where there is usually a downward change to mudstone dominated sediments (Hudleston Formation). It usually coincides with the base of a low gamma/high velocity spike. Locally, where the limestone is absent, the upper boundary is placed at a downward change from sandstone to variegated mudstone and a downward increase in gamma values and decrease in velocity.
Definition of Upper Boundary: The upper boundary is defined by a sharp down-section change from mudstones (Seeley Formation) or sandstones (Corallian Formation (Offshore)). A corresponding decrease in gamma values takes place at the boundary, and an increase in velocity.
Thickness: Up to 15 m.
Geographical Limits: Southern North Sea Basin, quadrants 42-43, 46-48, 51-52.
Parent Unit: West Sole Group (WSTS)
Previous Name(s): West Sole Group (WSTS)
Alternative Name(s): Cornbrash Formation
Stratotypes:
Type Section  North Sea Well 48/11b-4 between 1007 and 1022 m (Lott and Knox, 1994). 
Reference Section  North Sea Well 47/15a-3 between 1134 and 1149 m (Lott and Knox, 1994). 
Reference Section  North Sea Well 48/2-1 between 603.5 and 621 m (Lott and Knox, 1994). 
Reference Section  North Sea Well 47/14a-2 between 1033 and 1047 m (Lott and Knox, 1994). 
Reference(s):
Lott, G K and Knox, R W O'B. 1994. 7. Post-Triassic of the Southern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) 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