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Earth Science Conservation Review

Summary Full report
Western Marlbank; PolltullyardFermanagh
Site number:370File Number:H03
ESCC:IC
Locality Type:Cave, Sinkhole Status: ASSI
Grid Reference: H09443241
Google maps: 54.24087,-7.8558
County: FermanaghCouncil area:Fermanagh & Omagh District Council
Period:Quaternary, Carboniferous
Stages:Asbian, Holocene, Visean
Lithostrat:Dartry Limestone Formation, Knockmore Limestone Member
Site Description
image: 0370a.jpg Polltullyard: entrance passage in cherty facies of the Dartry Limestone.
Polltullyard: entrance passage in cherty facies of the Dartry Limestone.
Description:
At Polltullyard a small stream sinks in a 6m deep doline with a 2m limestone scarp on the southeastern side. At the base of the scarp 20m of passage developed in the cherty facies of the Dartry Limestone can be followed to the top of a 30m shaft.
image: 0370b.jpg Polltullyard: caver descending 30m shaft.
Polltullyard: caver descending 30m shaft.
image: 0370c.jpg Polltullyard: caver descending 30m shaft.
Polltullyard: caver descending 30m shaft.
The shaft and the passages below are developed in the Knockmore Limestone Member. The cave contains many deposits of cobble and boulder sized sandstone clasts which appear to be related to large dolines on the surface.

At the bottom of the shaft the stream sinking on the surface is met. Downstream the stream quickly disappears into pebbles and boulders. To the north a boulder slope descends for about 25m, bounded by a solid limestone wall on the north and on the south by massive gritstone boulders. This leads to a boulder filled chamber from where the stream disappears into a narrow rift. An abandoned passage runs parallel to the stream and after 30m encounters a choke of gritstone cobbles.

Upstream an awkward 4m climb enters 200m of well developed phreatic/vadose canyon passage. There are a total of four inlets.
image: 0370d.jpg Polltullyard: the upstream canyon passage showing large scalloping.
Polltullyard: the upstream canyon passage showing large scalloping.
image: 0370e.jpg Polltullyard: the upstream canyon passage showing large scalloping.
Polltullyard: the upstream canyon passage showing large scalloping.
image: 0370f.jpg Polltullyard: the upstream canyon passage showing large scalloping.
Polltullyard: the upstream canyon passage showing large scalloping.
Notes:
Polltullyard is a feature of the Shannon Pot System of the Western Marlbank area, in the Marlbank-Cuilcagh Mountain Region. For general information on the systems and features of this area, including this one, and a reference list, see site description 'Marlbank-Cuilcagh Mountain Region; Western Marlbank'.
Keywords
Rocks:Limestone
Structures:rift
Geomorph:cave, clastic sediments, doline, sinkhole
Measurements
Length:~300 mWidth:Height:
Depth:Area:  
Record type: ESCR report    
Entered by: Doughty, P.J.
Last updated:24 Dec 2003
 Enlander, I., Dempster, M. & Doughty, P., 2026. Western Marlbank; Polltullyard, County Fermanagh, site details. [In] Earth Science Conservation Review.
https://www.habitas.org.uk/escr/site.php?item=370. Accessed on 2026-11-07.

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