The BGS Lexicon of Named Rock Units — Result Details

Tullanaglare Mudstone Formation

Computer Code: TUG Preferred Map Code: TUGF
Status Code: Full
Age range: Langsettian Substage (CA) — Duckmantian Substage (CB)
Lithological Description: Mudstones, laminated mudstones, siltstones, sandstones, quartz-clastic palaeosols, sandy palaeosols, calcareous, grey and green-grey, commonly mottled purple-red.
Definition of Lower Boundary: Not exposed; faulted out.
Definition of Upper Boundary: Defined by top of Drumgivery Limestone Member; abruptly overlain, probably disconformably, by Drumlish Conglomerate Formation.
Thickness: 50 - 80m
Geographical Limits: Milltown Segment of the Fintona Block, Northern Ireland.
Parent Unit: Slievebane Group (SLI)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  North-flowing stream, 1.24km southwest of Porkhill Lough; by far longest section in this formation, does not extend to top part. 
Reference(s):
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, Johnston, T P and Legg, I C. 2004. Geology of the country around Kesh, Co. Fermanagh and Omagh, Co. Tyrone. Geological Sheets 32 and part of 31 (Kesh) and 33 (Omagh). Geological Survey of Northern Ireland. Technical Report GSNI 04/1. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable