The BGS Lexicon of Named Rock Units — Result Details

Windrush Member

Computer Code: WNR Preferred Map Code: notEntered
Status Code: Full
Age range: Asturian Substage (CAS) — Stephanian Stage (CS)
Lithological Description: Consists of approximately equal proportions of red and grey strata. The red intervals are dominated by red massive mudstone with beds of red silty mudstone with common dessication cracks. The grey intervals include upward-coarsening cycles of grey, locally reddened, mudstone to sandstone capped by seatearth and thin coal seams.
Definition of Lower Boundary: In the type section, reddish brown, blue mottled mudstone with calcareous nodules of the Windrush Member, overlies conformably grey mudstone of the Burford Coal Member.
Definition of Upper Boundary: The red and grey mudstones and sandstones of the Windrush Member are overlain unconformably by red mudstones of the Mercia Mudstone Group.
Thickness: Up to 590 m in the Upton Borehole
Geographical Limits: Oxfordshire Coalfield; although in the subsurface only.
Parent Unit: Grovesend Formation (GDB)
Previous Name(s): Windrush Formation (-1924)
Windrush Group (-3140)
Alternative Name(s): none recorded or not applicable
Type Section  Apley Barn Borehole SP31SW3, from the base of the member at 449.6 m to the unconformity at the base of the Mercia Mudstone Group at 250.2 m depth. Poole, 1969. 
Reference Section  Upton Borehole SP21SW1, from the base of the member at 928.29 m to the base of Mercia Mudstone Group at 337.49 m depth. Worssam, 1963. 
Worssam B C. 1963. The stratigraphy of the Geological Survey Upton Borehole, Oxfordshire. Bulletin of the Geological Survey of Great Britain, Vol. 20, 107-162. 
Waters, C N, Barclay, W J, Davies, J R and Waters, R A. In press. Stratigraphical framework for Carboniferous successions of Southern Great Britain (Onshore). British Geological Survey Research Report, RR/05/06. 
Poole E G. 1969. The stratigraphy of the Geological Survey Apley Barn Borehole, Witney, Oxfordshire. Bulletin of the Geological Survey of Great Britain, Vol. 29, 1-66. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: