St Cuthbert's Swallet
Encyclopedia
St Cuthbert's Swallet is the second longest, and most complex, cave on the Mendip Hills
Mendip Hills
The Mendip Hills is a range of limestone hills to the south of Bristol and Bath in Somerset, England. Running east to west between Weston-super-Mare and Frome, the hills overlook the Somerset Levels to the south and the Avon Valley to the north...

, in Somerset
Somerset
The ceremonial and non-metropolitan county of Somerset in South West England borders Bristol and Gloucestershire to the north, Wiltshire to the east, Dorset to the south-east, and Devon to the south-west. It is partly bounded to the north and west by the Bristol Channel and the estuary of the...

, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. It forms a major part of the Priddy Caves
Priddy Caves
Priddy Caves is an Area: 67.6 hectare geological Site of Special Scientific Interest at Priddy in the Mendip Hills, Somerset, notified in 1965.The entrance to St Cuthbert's Swallet is incorporated in the adjacent Priddy Pools SSSI....

 system and water entering this swallet re-emerges at Wookey Hole
Wookey Hole
Wookey Hole Caves is a show cave and tourist attraction in the village of Wookey Hole on the southern edge of the Mendip Hills near Wells in Somerset, England.Wookey Hole cave was formed through erosion of the limestone hills by the River Axe...

.
St Cuthbert's Swallet is part of, and lies underneath, the Priddy Pools
Priddy Pools
Priddy Pools is a geological Site of Special Scientific Interest at Priddy in the Mendip Hills, Somerset, notified in 1972.The pools provided the water supply for the Priddy Mineries which is now a Nature Reserve.- Biological :...

 Site of Special Scientific Interest
Site of Special Scientific Interest
A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...

. In the citation this is given as St Cuthbert's Cave, which should not be confused with St Cuthbert's Cave
St Cuthbert's Cave
St Cuthbert's Cave is a natural sandstone cave in Northumberland approximately 13 km from Dunstanburgh Castle. It is neither very big nor deep, but rather takes the form of an overhang large enough to provide shelter for a small group....

 in Northumberland
Northumberland
Northumberland is the northernmost ceremonial county and a unitary district in North East England. For Eurostat purposes Northumberland is a NUTS 3 region and is one of three boroughs or unitary districts that comprise the "Northumberland and Tyne and Wear" NUTS 2 region...

.

It is named because of its location in the St Cuthbert Out
St Cuthbert Out
St Cuthbert Out, sometimes Wells St Cuthbert Out is a civil parish in the Mendip district of Somerset, England. It entirely surrounds the city and parish of Wells. According to the 2001 census it had a population of 3,459. The parish is crossed by the Monarch's Way long distance footpath.The...

 parish of Wells
Wells
Wells is a cathedral city and civil parish in the Mendip district of Somerset, England, on the southern edge of the Mendip Hills. Although the population recorded in the 2001 census is 10,406, it has had city status since 1205...

, and was originally called St Cuthber's Pot.

History

Interest in the possible existence of a cave at this location existed prior to 1927, and increased when St Cuthbert's Pool suddenly drained away in that year. Attempts to discover an entrance took place between 1944 and 1953, when entry was finally gained. Exploration continued to push the known limits of the cave throughout the 1950s and 1960s. Sump
Sump (cave)
Sump is a term used in caving to describe a submerged passage in a cave. A sump may be static, with no inward or outward flow, or active, with continuous through-flow...

 1 was passed in 1969. Sump 2 has not yet been passed.

Access

Due to a still enforceable court injunction dating from 1863, which required that the stream now known to run through the cave to Wookey Hole was not polluted, the cave is locked and access is controlled by the Bristol Exploration Club on behalf of the land owners. No novices are allowed to enter.

Description

St Cuthbert's Swallet is a classic example of a deep phreatic
Phreatic
The term phreatic is used in Earth sciences to refer to matters relating to ground water below the water table . The term 'phreatic surface' indicates the location where the pore water pressure is under atmospheric conditions...

 cave system at a depth of not less than 280 feet (85 m) beneath the contemporary water table. It contains inclined bedding plane mazes at many levels, fault-guided rifts and some significant chambers. Nine successive phases of sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

 deposition, stalagmite
Stalagmite
A stalagmite is a type of speleothem that rises from the floor of a limestone cave due to the dripping of mineralized solutions and the deposition of calcium carbonate. This stalagmite formation occurs only under certain pH conditions within the underground cavern. The corresponding formation on...

 deposition and stream erosion have been recognised at the site, providing an exceptional record of environmental change through the warm and cold phases of the Ice Age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...

.

St. Cuthbert's Swallet is attractive to cavers, for its complexity and size, reaching over 6.7 km and a depth of 145m, and having numerous large decorated chambers, forming phreatic mazes on seven distinct levels. Among its displays are large and impressive calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...

 groups such as the 'Curtains', 'Cascade', Gour Hall with its 20 feet (6.1 m) high gour
Rimstone
Rimstone, also called gours, is a type of speleothem in the form of a stone dam. Rimstone is made up of calcite and other minerals that build up in cave pools. The formation created, which looks like stairs, often extends into flowstone above or below the original rimstone. Often, rimstone is...

, 'The Beehive', Canyon Series and the 'Balcony' formations in September Chamber, perhaps some of the best in Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

. There are also mini-formations including floating calcite crystals, over twenty nests of "cave pearl
Cave pearl
A cave pearl is a type of speleothem, a concretion of calcium salts which forms in limestone caves. They may be any shape but are formed of concentric layers, reaching up to in diameter. Most are smaller than wide. They can be found singly or grouped...

s", and delicate fern
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...

-like crystals less than four millimetres long.

The cave has also been identified as an important site for the study of cave insects
Cave insects
Caves are perhaps the most distinct and well-defined of insect habitats. A number of insects are permanent habitual inhabitants of caves, characterized by marked specializations for the extreme conditions. These are the true cavernicole species. Most caverniculous insect species are severely...

. Oligaphorura (formerly Archaphorura) schoetti are troglophiles, reaching 1.7 millimetre (0.0669291338582677 in) in length and they are common in many caves. Most specimens are female but a male specimen was collected from St. Cuthbert's Swallet in 1969.

External links

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