The BGS Lexicon of Named Rock Units — Result Details

Ashcombe Gravel Member

Computer Code: ACGR Preferred Map Code: notEntered
Status Code: Full
Age range: Albian Age (KA) — Cenomanian Age (KE)
Lithological Description: The member comprises three beds of coarse-grained sandstone and quartz gravel, separated by two coarse-grained, poorly sorted sandstone units, which show local cross-bedding and contain clay seams. The only common fossils are silicified oysters in the basal gravel.
Definition of Lower Boundary: Contact with the underlying Woodlands Sands Member. Upward facies-change from glauconitic clayey sandstones (Woodlands Sands Member) to coarse sandstones and gravels (Ashcombe Gravels Member).
Definition of Upper Boundary: Contact with the overlying Cullum Sands-with-Cherts Member, marked by the upward facies change from coarse-grained sandstones and gravels (Ashcombe Gravels Member) to sandstones containing chert horizons (Cullum Sands-with-Cherts Member).
Thickness: 5.28m.
Geographical Limits: Haldon Hills, Devon, Sheet 339.
Parent Unit: Upper Greensand Formation (UGS)
Previous Name(s): Haldon Sands (-1299)
Haldon Sands Formation (-4417)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Babcombe Copse Sandpit [SX 869 766], Selwood et al. (1984). 
Type Section  Temporary road cutting at Woodlands Goyle [SX 902 840], at the north end of Great Haldon, Selwood et al. (1984). 
Reference(s):
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. 
Ussher, W A E, 1913. Geology of the country around Newton Abbot. Memoir of the British Geological Survey, Sheet 339. (England and Wales). 
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). 
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. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable