Priddy Pools
Encyclopedia
Priddy Pools is a 52.7 hectares (130.2 acre) geological Site of Special Scientific Interest at Priddy
Priddy
Priddy is a village in Somerset, England in the Mendip Hills, close to East Harptree and north-west of Wells. It is in the local government district of Mendip....

 in 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...

, 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...

, notified in 1972.

The pools provided the water supply for the Priddy Mineries
Priddy Mineries
Priddy Mineries is a nature reserve previously run by the Somerset Wildlife Trust. It is in the village of Priddy, on the Mendip Hills in Somerset....

 which is now a Nature Reserve
Nature reserve
A nature reserve is a protected area of importance for wildlife, flora, fauna or features of geological or other special interest, which is reserved and managed for conservation and to provide special opportunities for study or research...

.

Biological

This site supports a very rich invertebrate and amphibian fauna. A wide range of seminatural habitats are present, including valley mire, open water, swamp and tall fen. These habitats have a restricted distribution in the Mendip Hills. Priddy Pools is situated in the central Mendip lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...

 orefield and the ecology of the area bears the mark of the lead industry. The northern pool was dammed in the 1850s to provide a supply of running water for the sifting and washing of slag. Lead was processed at St Cuthbert's Works until 1908. The hydrology of the site is complex. Nutrient-poor water flows from springs in the north of the site to St Cuthbert's Swallet
St Cuthbert's Swallet
St Cuthbert's Swallet is the second longest, and most complex, cave on the Mendip Hills, in Somerset, England. It forms a major part of the Priddy Caves system and water entering this swallet re-emerges at Wookey Hole....

 where it disappears before re-emerging 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...

. A valley mire has developed in the area immediately to the south of the springs. Sphagnum recurvum
Sphagnum
Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...

 and Sphagnum auriculatum
Sphagnum
Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...

 are the most frequent mosses, and a range of higher plants can be found. Additional interest lies in the flora that can tolerate high concentrations of lead in the soil such as Spring Sandwort
Minuartia
Minuartia is a genus of small flowering plants, one of those commonly known as "sandwort" or "stitchwort". The genus is classed within the family Caryophyllaceae, the pink family, characterised by its opposite and decussate leaves....

 (Minuartia verna) and the moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...

 Ditrichum plumbicola.

Priddy Pools supports a very rich fauna. 15 species of dragonfly
Dragonfly
A dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...

 have been recorded; as well as supporting the only population of Downy Emerald
Downy Emerald
The downy emerald is a species of dragonfly. It is metallic green and bronze in color, and its thorax is coated with fine hairs, hence its name. Like most other emeralds, the downy emerald has bright shiny green eyes...

 in the Mendips, the site hosts the notable Four-spotted Chaser
Four-spotted Chaser
The Four-spotted Chaser , known in North America as the Four-spotted Skimmer, is a dragonfly of the family Libellulidae found frequently throughout Europe, Asia, and North America....

 (Libellula quadrimaculata) and Ruddy Darter
Ruddy Darter
The Ruddy Darter is a European species of dragonfly of the family Libellulidae.-Description:The Ruddy Darter attains a wingspan of up to 6 cm. The head, thorax and abdomen of the male are vivid red, while the female is slightly smaller, and is a golden-yellow colour with black markings...

 (Sympetrum sanguineum). Five British species of amphibian occur and there are good populations of Great Crested Newt
Great Crested Newt
The Great Crested Newt, also called Northern Crested Newt or Warty Newt is a newt in the family Salamandridae, found across Europe and parts of Asia.-Distribution:...

 (Triturus cristatus), Smooth Newt
Smooth Newt
The Smooth Newt, also known as the Common Newt, Lissotriton vulgaris is the most common newt species of the Lissotriton genus of amphibians. L...

 (Triturus vulgaris) and Palmate Newt
Palmate Newt
The Palmate Newt is a species of newt found in most of Western Europe, including Great Britain. It is protected by law in all countries where it occurs, and is thought to be extremely rare to endangered in the Netherlands, Belgium and Luxembourg and vulnerable in Spain and Poland but common...

 (Triturus helveticus). 3 species of reptile, Viviparous Lizard
Viviparous lizard
The viviparous lizard or common lizard is a Eurasian lizard. It lives farther north than any other reptile species, and most populations are viviparous , rather than laying eggs as most other lizards do.-Identification:The length of the body is less than...

 (Lacerta vivipara), Adder (Vipera berus
Vipera berus
Vipera berus, the common European adder or common European viper, is a venomous viper species that is extremely widespread and can be found throughout most of Western Europe and all the way to Far East Asia. Known by a host of common names including Common adder and Common viper, adders have been...

), Grass Snake
Grass Snake
The grass snake , sometimes called the ringed snake or water snake is a European non-venomous snake. It is often found near water and feeds almost exclusively on amphibians.-Etymology:...

 (Natrix natrix), and at least 2 species of fish; European perch
European perch
The European perch, Perca fluviatilis, is a predatory species of perch found in Europe and Asia. In some areas it is known as the redfin perch or English perch, and it is often known simply as perch. The species is a popular quarry for anglers and has been widely introduced beyond its native area,...

, (Perca fluviatilis) and Three-spined stickleback
Three-spined stickleback
The three-spined stickleback, Gasterosteus aculeatus, is a fish native to much of northern Europe, northern Asia and North America. It has been introduced into parts of southern and central Europe.-Distribution and morphological variation:...

 (Gasterosteus aculeatus) are present. Breeding birds include Moorhen
Moorhen
Moorhens, sometimes called marsh hens, are medium-sized water birds that are members of the rail family Rallidae. They constitute the genus Gallinula....

 (Gallinula chloropus), Coot
Coot
Coots are medium-sized water birds that are members of the rail family Rallidae. They constitute the genus Fulica. Coots have predominantly black plumage, and, unlike many of the rails, they are usually easy to see, often swimming in open water...

 (Fulica atra), Mallard
Mallard
The Mallard , or Wild Duck , is a dabbling duck which breeds throughout the temperate and subtropical Americas, Europe, Asia, and North Africa, and has been introduced to New Zealand and Australia....

 (Anas platyrhynchos), Reed Bunting
Reed Bunting
The Reed Bunting, Emberiza schoeniclus, is a passerine bird in the bunting family Emberizidae, a group now separated by most modern authors from the finches, Fringillidae....

 (Emberiza schoeniclus) and Sedge Warbler
Sedge Warbler
The Sedge Warbler is an Old World warbler in the genus Acrocephalus. It is a medium-sized warbler with a brown, streaked back and wings and a distinct pale supercilium. Sedge Warblers are migratory, crossing the Sahara to get from their European and Asian breeding grounds to spend winter in Africa...

 (Acrocephalus schoenobaenus). Priddy Pools is an important research site. Detailed study of the algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 in the northern pool was carried out in the late 1960s and early 1970s, as part of the International Biological Programme.

Geological

The site contains the entrance to St Cuthbert's Swallet
St Cuthbert's Swallet
St Cuthbert's Swallet is the second longest, and most complex, cave on the Mendip Hills, in Somerset, England. It forms a major part of the Priddy Caves system and water entering this swallet re-emerges at Wookey Hole....

 cave, and overlies a large part of the cave complex reached through St Cuthbert's Swallet. This cave is an integral 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 which contains over 10 miles of surveyed cave passages divided between two major systems and four minor systems, all interconnected. All the caves are sink hole systems, fed by sink holes at the ground surface, and 3 of them exceed 100 metres in depth; in all the caves the detailed disposition and form of the passages can be seen clearly to have followed marked lines of natural weakness in the rocks. St Cuthbert's Swallet was formed by the erosive action of water flowing beneath the water-table at considerable depth (so called "phreatic development"). 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, containing 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 in St Cuthbert's Swallet, 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...

.

Use in literature

In his 1995 book "Our Game", John le Carré
John le Carré
David John Moore Cornwell , who writes under the name John le Carré, is an author of espionage novels. During the 1950s and the 1960s, Cornwell worked for MI5 and MI6, and began writing novels under the pseudonym "John le Carré"...

uses "Priddy Pool" as the site for the drowning of one of his characters.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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