The BGS Lexicon of Named Rock Units — Result Details

Woodward Formation

Computer Code: WDWR Preferred Map Code: notEntered
Status Code: Full, pending ratification
Age range: Oxfordian Age (JO) — Oxfordian Age (JO)
Lithological Description: The formation comprises pale to dark grey and calcareous mudstone with occasional thin interbedded sandstone and siltstone.
Definition of Lower Boundary: The lower boundary is defined by a downward change pale, silty mudstone to hard oolitic limestone (Corallian Formation, Offshore) or sandstone (Seeley Formation). There is a corresponding decrease in gamma values and an increase in velocity.
Definition of Upper Boundary: The upper boundary is marked by a downward change from dark, hard mudstone (Kimmeridge Clay Formation (Offshore)) to paler, more calcareous mudstone. On geophysical logs, the boundary is usually characterised by a down-section decrease in gamma values and an increase in velocity.
Thickness: Very variable in thickness up to a maximum of c. 90 m on the East Midlands Shelf (e.g. Well 47/14a-2).
Geographical Limits: North Sea UK Quadrants 42, 43, 47, 48, 51 and 52.
Parent Unit: Humber Group (HMBG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  North Sea well 47/14a-2; 878-966 m depth. Rhys (1974, p.7); Lott and Knox (1994). 
Reference Section  North Sea well 42/28-1 at 674-728 m depth. Lott and Knox (1994). 
Reference Section  North Sea well 47/9b-5A at 885.5-907.5 m depth. Lott and Knox (1994). 
Reference Section  North Sea well 47/18-1 at 739-820.5 m depth. 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