County Fermanagh
At 3.5km long, Pollaraftra is Fermanagh’s northen most cave of significance. Despite being isolated somewhat from the other speleological areas of the county it is regularly visited by student caving groups as a long beginners trip. In this respect it offers a great mix of challenges to the beginner with extended tight crawling, wading in water, and exposed traverses. It was one of the first caves I visited and I have returned many times.
These photos are from numerous trips including one in April of 2014 in which Tony Seddon dived a number of the cave’s sumps, some of which were first and last investigated over 40 years ago by Solari and Farr.
Pollaraftra has an interesting geological history. It is a classic fault cave (in which one part of the limestone bed has slipped relative to the other). While there is no major sink, water reaches the underground by diffuse overflow from the surrounding hills. This water subsequently carved out and extended the fault into a cave which has a series of active and non active parts. The active phreatic parts can only be explored by divers but the nonactive relict cave is relatively easy to traverse and has very fine features, including many speleothems.
In the first half of Pollaraftra, there are many segments that feature elements which describe a cave in decay, such as in the Boulder Chamber and Luncheon Shelves, these are large chambers in which the roof is in a state of collapse. Enormous slabs and boulders are piled on top of one another and the roof is flat and clean of any calcite features that may once have decorated these parts of the cave.
In the second half of the cave there are a series of sumps and high level passages. Sumps, which lead to water filled phreatic passageways, represent active cave passages being expanded by acidic dissolution. In the higher level passages, such as the Canal Series, classic features of abandoned streamway can be observed. The best of these can be seen at the Gour Pools.
These are a series of delicate calcite gours with crystal clear water decorated with beautiful calcite flowstone walls. This area comes as quite a surprise, as to get here, an area of exceptionally muddy passage has to be traversed. Cavers will typically remove wellies on approach to the gour pools to avoid redepositing mud which would damage the pools. I have observed freshwater prawns in these pools, so respect of this unique habitat needs to be maintained.
In Spring 2016 I visited the cave with Laura van der Sluis and Mike Simms for the purpose of recovering animal bones calcited to a wall but becoming increasingly exposed by continual high water levels in the cave. My purpose was to lead the researchers to the location where the bones were located (van der Sluis, 2016).
The recovered bones were subsequently analysed by a zoo-archaeologist and radiocarbon dated at Queen’s University in that year. The analysis revealed two distinct bone assemblages; one of bovine origin dating from the Bronze age and one of cervid (deer) origin dating to the Early Medieval era. All the bones showed signs of butchery as well as rodent gnaw marks, suggest that bones were originally deposited outside the cave but subsequently washed in.
Our cave environments are unique places that relatively few people get to experience. They are vast storehouse of geological, sedimentological and archaeological heritage. The information is there and keen eyes amongst cavers can help reveal the unique backstories hiding in even the most frequently traversed of our caves.
All excavations carried out with permission obtained from Northern Ireland Sites and Monuments Record;
Pollaraftra Cave is currently closed to access.
references
van der Sluis, L., 2016. Animal bones from the Bronze Age and Early Middle Ages found in Pollaraftra Cave, Co. Fermanagh, Irish Speleology, 22, 53-58.
Caves Of Ireland 