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Earth Science Conservation Review
| Carricklongfield Quarry | Tyrone |
| Site number: | 257 | File Number: | H75 |
| ESCC: | ED | ||
| Locality Type: | Quarry (disused) | Status: | local interest |
| Grid Reference: | H716544 Centroid | ||
| Google maps: | 54.43355,-6.89663 | ||
| County: | Tyrone | Council area: | Mid Ulster District Council |
| Period: | Carboniferous | ||
| Stages: | Visean | ||
| Lithostrat: | Carrickaness Sandstone Formation, Tyrone Group | ||
| Site Description | |
|---|---|
| Highlights: | |
Very good quarry exposure of calcareous sandstones of the Carrickaness Sandstone Formation. | |
| Description: | |
Several quarries were originally worked in this area of Carricklongfield Townland just over 5km ENE of Aughnacloy. The chosen quarry is the most easterly of the group and exposes 10- 12m of strata dipping southwards at about 15 deg. Major bedding surfaces are widely spaced at up to 2m apart but internal variations in the carbonate content of finely laminated or more massive sandstones impart a "bedded" appearance to the rock face. Pale grey to fawn-grey medium to coarse- grained calcareous sandstones are the commonest lithology. Very calcareous bioclastic horizons frequently consist of coarse- grained sandy grainstone, with some ooliths and rounded intra- clasts of micritised fine to medium-grained peloidal packstone. Broken bioclasts are very common and include fragments of crinoid ossicles, brachiopods and numerous chips of algae including Ungardella sp., stacheiinids and Koninckopora inflata which shows that the sandstone is not younger than Asbian. Occasional very large specimens of concavo-convex brachiopods resembling Gigantoproductus are further evidence of a possible Asbian age for this sandstone. | |
| Interpretation: | |
The occurrence of grainstones with abundant remains of marine benthic animals and algae is good evidence that this sandstone, certainly in the lower part of the sequence, was deposited in a marine environment. Evidence for turbulence and deposition from currents occurs in the form of ooliths, the broken nature of the bioclasts and the planar and, much more rarely, the trough cross- laminations. Higher in this formation, in the vicinity of Legane Lough (H73 53), there are records of coal being recovered during quarrying operations for the sandstone although no such evidence is known to occur in outcrop at the present time. The accumulation of plant debris in a bed of sufficient thickness to form a coal seam requires a sustained period of subaerial exposure of a sediment surface and growth of luxuriant vegetation. Whilst such an event is less likely to occur in a marine environment it suggests that there was a gradual regression of the sea, brought about by a seaward progression of the delta sands, and emergence of the sediment surface as sedimentation rates exceeded subsidence of the sand body. The rare occurrence of large specimens of the solitary coral Siphonophyllia sp. benburbensis group in calcareous sandstones exposed at The Rock (op. cit.), 5.1km SE of Aughnacloy is further evidence of an Asbian age for this formation and of the proximity of a marine environment throughout the deposition of much of the sandstone. | |
| Conclusions: | |
CONCLUSION Carricklongfield Quarry is one of the best exposures of the Carrickaness Sandstone Formation in the Aughnacloy-Tynan area. | |
| Notes: | |
For information on other sites in Subarea-5 see; Key Site 1178 - Subarea-5; Clogher-Aughnacloy. | |
| Keywords | |
|---|---|
| Rocks: | Sand, Sandstone |
| Fossil Groups: | Alga, Brachiopod, Crinoid |
| Fossil List: | Koninckopora inflata, Siphonophyllia benburbensis |
| Relations: | Marine sediments |
| Measurements | |||||
|---|---|---|---|---|---|
| Length: | Width: | Height: | 10-12 m | ||
| Depth: | Area: | ||||
| Access | |
|---|---|
| Approach: | Just over 5km ENE of Aughnacloy. |
| Record type: | ESCR report | ||
| Entered by: | Doughty, P.J. | ||
| Last updated: | 8 Jan 2005 | ||
| Enlander, I., Dempster, M. & Doughty, P., 2026. Carricklongfield Quarry, County Tyrone, site details. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/site.php?item=257. Accessed on 2026-11-06. |
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