The BGS Lexicon of Named Rock Units — Result Details

Trusham Shale Formation [Obsolete Name And Code: Use TMMU]

Computer Code: TMSH Preferred Map Code: TmSh
Status Code: Index Level
Age range: Tournaisian Stage (CT) — Tournaisian Stage (CT)
Lithological Description: Olive-green shales and pale grey micaceous shales with Sanguinolites? ellipticus. Locally (eg in the aureole of the Dartmoor Granite) cannot be separated from the Hyner Shale.
Definition of Lower Boundary: Conformable passage from the dark olive or bluish green shales and mudstones of the Hyner Shale.
Definition of Upper Boundary: Taken at upward change to bluish black shales of the Combe Shale (probable conformable junction).
Thickness: Teign Valley 60m (Selwood and others, 1984).
Geographical Limits: Middle Teign Valley, Devon.
Parent Unit: Not Entered (?)
Previous Name(s): Trusham Formation (-3728)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Track section north of Leigh, near Trusham (SX 855 822), Devon. 64m of green shales with ostracods. (Selwood and others, 1984, p 67). 
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). 
Chesher, J A, 1968. The succession and structure of the Middle Teign Valley. Proceedings of the Ussher Society, Vol.2, 15-17. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E339