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Earth Science Conservation Review
| Reyfad-Carrickbeg; Reyfad Pot | Fermanagh |
| Site number: | 391 | File Number: | H04 |
| ESCC: | IC | ||
| Locality Type: | Cave | Status: | ASSI |
| Grid Reference: | H08894687 | ||
| Google maps: | 54.37025,-7.86458 | ||
| County: | Fermanagh | Council area: | Fermanagh & Omagh District Council |
| Period: | Quaternary, Carboniferous | ||
| Stages: | Holocene, Visean | ||
| Lithostrat: | Carn Limestone Member, Dartry Limestone Formation, Glenade Sandstone Formation, Glencar Limestone Formation, Knockmore Limestone Member, Meenymore Formation | ||
| Site Description | |
|---|---|
| Description: | |
UNDERGROUND KARST The Reyfad-Pollnacrom-Polltullybrack cave system is developed mainly in the Knockmore Limestone Member. The regional dip is typically 10-20 degrees, varying in direction between west and south. The cave formation is predominantly aligned on two sets of fractures, trending approximately 340° and 010°. There are only a few E-W controlling joints. The horizontal part of the cave has formed between 230m and 130m amsl. The Reyfad shaft system is developed on a major fault and breaks through the Cherty Facies of the Dartry Limestone into the Knockmore Limestone Member. The 90m deep shaft has irregular cross sections and breccia lines the walls. Collapse blocks form a constriction before the shaft breaks through into the roof of the Main Chamber. The passage at this point is 15m high and 10m wide with the Reyfad stream emerging from the canyon under collapse boulders on the east wall. To the north of the shaft inlet is a steep sediment slope leading up to the bottom of a large calcited aven. The Main Stream Passage continues south for 200m with huge boulders and sediment banks which in some places fill the passage almost to the roof. In certain areas a well developed roof tube with scallops can be seen and there are areas of anastomoses and phreatic sponge work. There are also areas of breccia in the walls and roof of the passage. The stream finds a route through the breakdown and sediment banks to disappear into the boulder choke under the Southern Inlet Passage. This confusingly named passage (it is, in fact, an outlet) is nearly full of sediment and can only be followed along the shrinkage gap between roof and sediment. The roof is developed on a fossiliferous bed which exposes fine specimens of crinoid and brachiopod fossils over the surface of its 20m wide roof. Access to the Aghnahoo Extension Passage, where the Reyfad Stream is rejoined, is via breakdown on the west wall of the Southern Inlet Passage. The Aghnahoo Extension takes the stream south- southeast almost continuously on a major structural trend for 1250m. The large canyon passage averages 10m high and 3m wide with a number of breakdown blockages, a sediment covered floor, deep lakes and sumps. The passage is also characterised by mud banks and mud cover of walls with complete mud choking above the sump at the southern limit. The Reyfad stream in the Aghnahoo Extension has been joined by the second of the main streams in the system (North West Inlet stream) somewhere in the breakdown and sediment fill of the Confusion Chamber-Campsite area. This stream enters the system via Watson's Aven from Watson's Sink and on leaving the Aven can only be followed for a relatively short section of active negotiable streamway before entering a sump. The fossil Formation Passage of Watson's Way bypasses this phreatic section and has excellent speleothem deposits. There are examples of cave pearls, curtains, flow stones, straws etc. of very pure, white calcite. The stream re-emerges from a sump in Zig-Zag passage and continues to the North West Inlet. The passage attains dimensions of 20m wide and 8m high with a flat bedding controlled roof. The roof exhibits dissolution pockets along joints and there are remnants of a phreatic half tube with scalloping in some areas. The most striking features in the North West Inlet are the sediment banks which are the largest and most impressive in the cave. They consist of layered fine muds and sands up to 7m thick through which the stream has cut a path. Towards the southern end of the North West Inlet, before Confusion Cavern, the sediments fill the passage to the roof at the Gypsum Crawls. As the name suggests this, area is characterised by a coating of gypsum deposits on the sediment surface. There is also an area of unusual short thick helictites on the wall and roof of one crawl passage. To the west and north of the Inlet are the series of fossil passages and interconnected active passage hosting the three other streams of the system. Both Scrapers' Hole and the Bear Pit can be followed into Scrapers' Downstream and Reyfadhoo Passages. These passages carry a small stream and vary in size from a 6m wide 4m high passage with mud banks ending in tight vadose passages with short phreatic sections. The Reyfadhoo stream seems to be a combination of the Old Bog Road - Scrapers' water and the Heaven and Hell water from Pollnacrom. The Old Bog Road has a glutinous mud floor but has fine straw stalactites and other speleothems in a phreatic domed roof. Other calcite sediments in the Joe's Roe and Dreamer's Diversion area are notable. At the northern end of the Old Bog Road a tight vadose passage and a breakdown area can be passed to reach the New River, formed by water entering via the Shower Room. Here, the water enters the system down a series of avens, and is assumed to be the stream sinking at Waterfall Pot. This water is soon lost into the boulder choke under the sediment filled passages of Excremental Way and Coleman's Cavern. | |
| Notes: | |
Reyfad Pot is a feature of the Reyfad-Carrickbeg area of the Belmore, Ballintempo and Tullybrack Uplands. For general information on the systems and features of Reyfad-Carrickbeg, including this one, and a reference list, see site description 'Belmore, Ballintempo & Tullybrack Uplands; Reyfad-Carrickbeg'. | |
| Keywords | |
|---|---|
| Minerals: | Calcite, Gypsum |
| Rocks: | Breccia, Chert, Limestone |
| Fossil Groups: | Brachiopod, Crinoid |
| Structures: | bedding, fault, joints, rift |
| Geomorph: | breakdown, cave, cave pearls, clastic sediments, flowstone, helictite, sinkhole, speleothem, stalactite, straw, sump |
| Record type: | ESCR report | ||
| Entered by: | Doughty, P.J. | ||
| Last updated: | 24 Dec 2003 | ||
| Enlander, I., Dempster, M. & Doughty, P., 2026. Reyfad-Carrickbeg; Reyfad Pot, County Fermanagh, site details. [In] Earth Science Conservation Review. https://www.habitas.org.uk/escr/site.php?item=391. Accessed on 2026-11-08. |
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