The BGS Lexicon of Named Rock Units — Result Details

Altagoan Formation

Computer Code: AF Preferred Map Code: AF
Status Code: Full
Age range: Tournaisian Stage (CT) — Tournaisian Stage (CT)
Lithological Description: Variable thin-bedded sediments: pebbly sandstones, laminated micaceous sandstones, siltstones, shaly mudstones, shales, thin micritic algal stromatolites.
Definition of Lower Boundary: Unknown but probably conformable with Iniscarn Formation.
Definition of Upper Boundary: Unknown but probably conformable with Desertmartin Limestone Formation.
Thickness: Unknown
Geographical Limits: Desertmartin area, Co.Londonderry, Northern Ireland.
Parent Unit: Tyrone Group (TYRO)
Previous Name(s): Upper Calciferous Sandstones (-3156)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Partial Type Section  Lower part of formation: Drumard Water, above and below 300ft contour 
Partial Type Section  Altagoan River, upstream from Altagoan Bridge. 
Reference(s):
Geological Survey of Northern Ireland, 1983. Cookstown sheet 27, solid 1:50,000. 
Eagan, F W, 1881. Explanatory memoir to accompany sheet 27 of the maps of the Geological Survey of Ireland 
Owens, B, Gueinn, K J and Cameron, I B, 1977. A Tournaisian miospore assemblage from the Altagoan Formation (Upper Calciferous Sandstone) Draperstown, Northern Ireland. Pollen et Spores, Vol. XIX, No.2. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
N27