The BGS Lexicon of Named Rock Units — Result Details

Tralorg Shale Formation

Computer Code: TLG Preferred Map Code: TLG
Status Code: Full
Age range: Llandovery Epoch (SL) — Llandovery Epoch (SL)
Lithological Description: Grey, brown and black mudstones, and thin beds of gritty sandstone.
Definition of Lower Boundary: Disconformable junction with Shalloch Formation (Ordovician).
Definition of Upper Boundary: Conformably overlain by Saugh Hill Grits Formation.
Thickness: 60-180m
Geographical Limits: Girvan area, south-west Scotland.
Parent Unit: Newlands Subgroup (NEWL)
Previous Name(s): Modestus Shales (-1235)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Penwhapple Burn, SO08W. 
Reference(s):
Cocks, L R M and Toghill, P, 1973. The biostratigraphy of the Silurian rocks of the Girvan District, Scotland. Journal of the Geological Society of London, Vol. 129, 209-243. 
Lapworth, C, 1882. The Girvan Succession. Quarterly Journal of the Geological Society of London, Vol. 38, 537-666. 
Floyd, J D and Williams, M. 2003. A revised correlation of Silurian rocks in the Girvan district, SW Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences, Vol. 93 (for 2002), 383-92. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S008