The BGS Lexicon of Named Rock Units — Result Details

Culham Sands With Cherts Member

Computer Code: CUSC Preferred Map Code: notEntered
Status Code: Full
Age range: Cenomanian Age (KE) — Cenomanian Age (KE)
Lithological Description: Sandstone with horizons of chert, overlain by chert-free, clayey, laminated sandstone with cross-bedded lenses. Thin green clay-rich horizons occur in the basal part of the member, associated with glauconitic and pebbly sandstone. Tourmaline-rich sandstones locally form the highest part of the member.
Definition of Lower Boundary: Contact with the underlying Ashcombe Gravels Member, marked by the upward facies change from pebbly sands and gravels (Ashcombe Gravels Member) to sandstones with cherts (Cullum Sand-with-Cherts Member).
Definition of Upper Boundary: Unconformable contact with overlying Eocene flint-rich gravels
Thickness: 6.71m.
Geographical Limits: Haldon Hills, Devon, Sheet 339.
Parent Unit: Upper Greensand Formation (UGS)
Previous Name(s): Haldon Sands Formation (-4417)
Haldon Sands (-1299)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Temporary road cutting at Woodlands Goyle [SX 902 840], at the north end of Great Haldon, Selwood et al. (1984). 
Reference Section  Cullum Goyle [SX 893 830], near race course on Great Haldon, Selwood et al. (1984). 
Reference(s):
Selwood, E B, Edwards, R A, Simpson, S, Chesher, J A, Hamblin, R J O, Henson, M R, Riddolls, B W and Waters, R A. 1984. Geology of the countryside around Newton Abbot. Memoir of the British Geological Survey, Sheet 339 (England and Wales). 
Hamblin, R J O and Wood, C J. 1976. The Cretaceous (Albian-Cenomanian) stratigraphy of the Haldon Hills, south Devon, England. Newsletters on Stratigraphy, Vol.4, 135-149. 
Jukes-Browne, A J and Hill, W. 1900. The Cretaceous Rocks of Britain. 1. Gault and Upper Greensand. Memoir of the Geological Survey of Great Britain. 
Ussher, W A E, 1913. Geology of the country around Newton Abbot. Memoir of the British Geological Survey, Sheet 339. (England and Wales). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable