The BGS Lexicon of Named Rock Units — Result Details

Bin Mountain Sandstone Formation

Computer Code: BNMS Preferred Map Code: BNMS
Status Code: Full
Age range: Chadian Substage (CI) — Chadian Substage (CI)
Lithological Description: Sandstone, pale to mid grey, very calcareous, fine- to medium-grained, small bioclast fragments, bioturbated, and limestones, blue-grey, oolitic, crinoidal, very sandy, scattered quartz pebbles.
Definition of Lower Boundary: Abrupt change from peritidal micrites and shales of Termon River Limestone Formation to thick beds of crinoidal calcareous sandstone/sandy packstone of Bin Mountain Sandstone Formation. Conformable.
Definition of Upper Boundary: Conformable, apparently gradual change from calcareous sandstones and sandy grainstones of Bin Mountain Sandstone Formation to dark blue-grey fossiliferous sandy packstones and packstones of Ballyshannon Limestone Formation.
Thickness: 80 - 100m.
Geographical Limits: Kesh-Omagh area of the northwest Carboniferous basin of Ireland.
Parent Unit: Tyrone Group (TYRO)
Previous Name(s): Formerly Included In Claragh Sandstone Group (-70)
Alternative Name(s): none recorded or not applicable
Type Section  Low cliff face at Binnawooda Spring and rough farm track leading south from there to summit of Bin Mountain, exposes base of formation and most of c.25 metre formation thickness hereabouts. 
Type Area  Numerous exposures and linear scarp features in superficial deposit-free ground straddling the Willmount Road between Barravey and Tullyard townlands. Typical exposures of calcareous sandstones and sandy grainstones. 
Simpson, I M, 1954. The Lower Carboniferous stratigraphy of the Omagh Syncline, Northern Ireland. Quarterly Journal of the Geological Society of London, Vol.110, 391-408. 
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