The BGS Lexicon of Named Rock Units — Result Details

Fish Bed Formation

Computer Code: FBD Preferred Map Code: FBD
Status Code: Full
Age range: Sheinwoodian Age (SS) — Sheinwoodian Age (SS)
Lithological Description: Greenish-grey silty mudstones and siltstones with interbedded fine-grained sandstone beds to 1m thick. The siltstones are laminated and have some small-scale cross-bedding.
Definition of Lower Boundary: Base of lowest grey sandstone bed above the reddish mudstones of the underlying Dovestone Redbeds. The sandstone may be stained red or brown.
Definition of Upper Boundary: Upper surface of highest greyish-coloured sandstone or siltstone below the overlying reddish mudstones of the Gully Redbed Formation; transitional.
Thickness: 58m
Geographical Limits: Lower Palaeozoic inlier of the Hagshaw Hills, Scotland, (50k Sheets 23W, 23E and 15W).
Parent Unit: Glenbuck Group (GBK)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  Sheil Burn, right-hand tributary of the Monk's Water, 1km northwest of Monksfoot Farm. 
Reference Section  Douglas Water section, 1.4km southwest of Parish Holm Farm. 
Type Section  Lochside exposures, Glenbuck Loch 0.3km, northwest of Parish Holm Farm. 
Reference(s):
Rolfe, W D I, 1961. The Geology of the Hagshaw Hills Silurian Inlier, Lanarkshire. Transactions of the Edinburgh Geological Society, Vol.18, Part 3, 240-269. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
S023 S023 S015