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Earth Science Conservation Review
| Ballagh Quarry | Fermanagh |
| Site number: | 208 | File Number: | H43 |
| ESCC: | ED | ||
| Locality Type: | Quarry (disused) | Status: | ASSI |
| Grid Reference: | H42503133 Centroid | ||
| Google maps: | 54.22931,-7.3483 | ||
| County: | Fermanagh | Council area: | Fermanagh & Omagh District Council |
| Period: | Carboniferous | ||
| Stages: | Asbian, Visean | ||
| Lithostrat: | Dartry Limestone Formation, Tyrone Group | ||
| Site Description | |
|---|---|
| Highlights: | |
Ballagh Quarry is the stratotype for the Ballagh Limestone Member, a new lithostratigraphical unit within the Dartry Limestone Formation. | |
| Description: | |
Ballagh Quarry is located some 6.5km ESE of Lisnaskea and just over 2km east of Rockfield Quarry (Key Site 209). The quarry or excavation is now largely infilled and built over but the Ballagh Limestone Member is still exposed in some parts of the former quarry. The probable lithostratigraphical position of the member within the Dartry Limestone Formation, and its thickness, may be deduced from the exposure of the topmost strata of the formation in Rockfield Quarry, below the contact with the succeeding Meenymore Formation. Because the quarry exposure is inaccessible it is necessary to select a site where the Ballagh Member may be sampled, but where it is, unfortunately, not possible to define its true thickness or its position in the formation. In Rockfield Quarry, it is believed that the 5-6m of pale weathering, shale- free limestones that occur between 13-20m below the top of the formation are the equivalent of the Ballagh Member and its stratotype. In outcrop the Ballagh Limestone Member consists of pale fawn to medium fawn-grey, very coarse-grained crinoidal grainstone. Other bioclasts form only a small part of the rock and consist of tiny fragments of brachiopod shells. Bedding is massive with crude internal laminations produced by grain size variations. No fossils diagnostic of the age of the member were recovered from the quarry. | |
| Interpretation: | |
The very fine-grained spicular limestones that form the bulk of the Dartry Limestone Formation appear to reflect deposition in a relatively deep water, tranquil environment. The occurrence of grainstones, of the Ballagh Member, near the top of the Dartry Formation could be an indication of an episode of shallow water, turbulent conditions. This is particularly hard to envisage in terms of sudden bathymetric shallowing, and deposition of the grainstones, followed equally abruptly by an instantaneous return to deep water, anoxic conditions as evidenced by the 0.9m of black, ferruginous shale that rests directly on top of the Ballagh Member in Rockfield Quarry. Given the apparently variable thickness of the Ballagh Member and its restricted distribution, it is possible that the grainstones, which would have accumulated in shallow water in a basin marginal location were subsequently transported downslope into a deep water location, where mud and fine, spicular carbonates, that are so typical of the rest of the Dartry Limestone Formation, were being deposited. This suggestion is, at present, pure speculation and cannot yet be proven or disproven. | |
| Conclusions: | |
Ballagh Quarry is the stratotype section for the Ballagh Limestone Member of the Dartry Limestone Formation. | |
| Notes: | |
For information on other sites in Subarea-2 see; Key Site 1175 - Subarea-2; Lisnaskea-Fivemiletown. | |
| Keywords | |
|---|---|
| Rocks: | Limestone |
| Fossil Groups: | Brachiopod, Crinoid |
| Relations: | Marine sediments |
| Access | |
|---|---|
| Approach: | Ballagh Quarry is located some 6.5km ESE of Lisnaskea and just over 2km east of Rockfield Quarry (H405310). |
| Record type: | ESCR report | ||
| Entered by: | Doughty, P.J. | ||
| Enlander, I., Dempster, M. & Doughty, P., 2026. Ballagh Quarry, County Fermanagh, site details. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/site.php?item=208. Accessed on 2026-11-04. |
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