The BGS Lexicon of Named Rock Units — Result Details

Whiteway Mudstone Formation

Computer Code: WWYM Preferred Map Code: notEntered
Status Code: Full
Age range: Famennian Age (DA) — Tournaisian Stage (CT)
Lithological Description: Consists predominantly of red and purple mudstone with subordinate green and grey-black, locally laminated mudstone. Calcareous nodules are common where the formation is condensed and near the base, but in thicker developments calcareous, siliceous and, rarely, sideritic nodules and laminae are sparsely present. The mudstones and calcareous nodules contain a rick planktonic fauna of ammonoids, ostracods and conodonts; benthic fauna include crinoid debris and brachiopods, amongst others. Thin units of basalitic (spilitic) lava are sparsely present in thicker developments.
Definition of Lower Boundary: The lower boundary is taken at the gradational incoming of red, purple and green mudstones with scattered limestone nodules of the Whiteway Mudstone Formation above the red and green nodular cephalopod limestones with subordinate mudstones of the underlying Luxton Nodular Limestone.
Definition of Upper Boundary: The upper boundary is taken at the incoming of black sooty and siliceous mudstones of the Winstow Mudstone Member (basal Winstow Chert Formation) above the purple, green and grey mudstones of the underlying Whiteway Mudstone Formation. The contact is generally sharp.
Thickness: 26 - ?200m
Geographical Limits: Between Chudleigh (SX 870 784), Bishopsteignton (SX 905 735) and East Ogwell (SX 845 695) areas, south Devon.
Parent Unit: Tamar Group (TAMA)
Previous Name(s): Mount Pleasant Group (Pars) (-3780)
Saltern Cove Formation (Pars) (-3148)
Whiteway Slate Formation [Obsolete Name And Code: Use WWYM] (WYSL)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Cutting at the rear of a barn in the eastern side of Whiteway Barton farmyard, 2km northnortheast of Kingsteignton, south Devon. The section (45m thick) is in pale green and buff mudstones in the upper part of the Formation and spans the Devonian-Carboniferous boundary. Neither the basal nor upper boundary of the Formation is seen. 
Reference(s):
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. 
Leveridge, B E, Scrivener, R C, Goode, A J J and Merriman, R J. 2003. Geology of the Torquay district - a brief explanation of the geological map. Sheet explanation of the British Geological Survey. 1:50 000 Sheet 350 Torquay (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). 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable