The BGS Lexicon of Named Rock Units — Result Details

Ugbrooke Sandstone Formation

Computer Code: UGST Preferred Map Code: notEntered
Status Code: Full
Age range: Brigantian Substage (CX) — Namurian Stage (CN)
Lithological Description: Thick-bedded massive, grey, medium-to coarse-grained, locally pebbly and conglomeratic sandstones with impersistent thick units of pebble-cobble conglomerate, argillaceous sandstone and dark grey mudstones with thin sandstones and siltstones. Pebbly mudstones are also present. Conglomerate clasts include chert and granite.
Definition of Lower Boundary: The base is taken at the incoming of dark grey and greenish grey mudstones with thin siltstones and fine- to coarse-grained sandstones of the Ugbrooke Sandstone Formation above the thin-bedded cherts, shales and limestones of the underlying Winstow Chert Formation.
Definition of Upper Boundary: The upper boundary is taken at an angular unconformity, where fine grained glauconitic sandstone at the Upper Greensand Formation rests upon thick-bedded to massive, locally pebbly to conglomeratic sandstone of the Ugbrooke Sandstone Formation.
Thickness: Not known, but at least 500m.
Geographical Limits: Chudleigh (SX 870 784) and East Ogwell (SX 845 695) areas, south Devon.
Parent Unit: Chudleigh Group (CHUD)
Previous Name(s): Ugbrooke Park Sandstones (-589)
Ugbrooke Park Beds (-1890)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Quarry in Ugbrooke Park, 0.75km west of Ugbrooke House, Chudleigh, south Devon. Section exhibits about 10m of thick-bedded sandstones in the middle of the exposed part of the Formation. Neither the top nor the base of the Formation are exposed. 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). 
House, M R and Butcher, N E, 1973. Excavations in the Devonian and Carboniferous Rocks near Chudleigh, south Devon. Transactions of the Royal Geological Society of Cornwall, Vol.20, p.199-220. 
Ussher, W A E. 1882. The British Culm Measures. Proceedings of the Somerset Archeological and Natural History Society, Vol.38, 111-219. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E339