The BGS Lexicon of Named Rock Units — Result Details

Shanmullagh Formation

Computer Code: SHAN Preferred Map Code: SHAN
Status Code: Full
Age range: Famennian Age (DA) — Famennian Age (DA)
Lithological Description: Sandstone, purple-brown, fine- to medium-grained, thin to very thick beds; and purple-red siltstones and mudstone; ripples.
Definition of Lower Boundary: Not exposed: unconformable, in the east on Sheet 34 (Pomeroy) on Lower Palaeozoic sediments and on varied igneous/metamorphic lithologies of Tyrone Volcanic Complex (Palaeozoic).
Definition of Upper Boundary: Not exposed; overlain unconformably by Lower and Upper Carboniferous sediments.
Thickness: Not known; probably >1000m
Geographical Limits: The Irvinestown segment of the Fintona Block, Northern Ireland.
Parent Unit: Fintona Group (FIN)
Previous Name(s): Ballinamallard Mudstone Formation (BLM)
Fintona Group (FIN)
Fintona Beds (-3404)
Alternative Name(s): none recorded or not applicable
Type Area  Numerous superficial deposit-free areas and stream section in Drumharrey Townland, Drumduff Townland, 300m east and 500m east-south-east of the stratotype. 
Type Section  Disused quarry at Shanmullagh West, 2.4km north-north-east of Irvinestown. Exposes particularly arenaceous part of the sequence. 
Nolan, J, 1880. On the Old Red Sandstone of the north of Ireland. Quarterly Journal of the Geological Society of London, Vol.36, 529-535. 
House, M R, Richardson, J B, Chaloner, W G, Allen, J R L, Holland, C H and Westoll, T S. 1977. A Correlation of Devonian rocks of the British Isles. Geological Society of London, Special Report No.8, Scottish Academic Press, Edinburgh. 
Mitchell, W I and Owens, B, 1990. The geology of the western part of the Fintona Block, Northern Ireland: Evolution of Carboniferous basins. Geological Magazine, Vol.127 (5), 407-426. 
Mitchell, W I and Owens, B, 1990. Used on 1:50,000 geological maps of the Kesh (Sheet 32) area; to be included in Memoir of the Kesh-Omagh (Sheets 32/33) area, p.411. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: