The BGS Lexicon of Named Rock Units — Result Details

Toomebridge Sandstone Formation

Computer Code: TOOM Preferred Map Code: TOOM
Status Code: Full
Age range: Early Triassic Epoch (TE) — Early Triassic Epoch (TE)
Lithological Description: Sandstone, orange-red, up to medium-grained with some coarse sand grains, sub-angular to well rounded, weakly cemented; thin siltstone and mudstone layers, brick-red.
Definition of Lower Boundary: Gradational with red mudstones and sandstones at the top of the underlying Drumcullen Formation.
Definition of Upper Boundary: Sharp contact with red mudstones and siltstones at the base of the succeeding Mercia Mudstone Group.
Thickness: 191.4 - 199.9m [628-656 ft]
Geographical Limits: Sub-surface on the northwest shore of Lough Neagh.
Parent Unit: Sherwood Sandstone Group (SSG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Reference Section  Annaghmore-1 Borehole. GSNI Borehole Database Number 94SE/1 [1632-2260ft--497.4-688.8m] Based on cutting samples at 10ft intervals of which a split sample is stored with the Geological Survey of Northern Ireland. 
Naylor, D, Philcox, M E and Clayton, G. 2003. Annaghmore-1 and Ballynamullan-1 wells, Larne-Lough Neagh Basin, Northern Ireland. Irish Journal of Earth Sciences, Vol.21, 47-69. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable