Rock-cut basin
Encyclopedia
A rock-cut basin, in this usage of the term, is a natural phenomenon. They are cylindrical depressions cut into stream or river beds, often filled with water. Such plucked-bedrock pits are created by kolk
Kolk
A kolk is an underwater vortex that is created when rapidly rushing water passes an underwater obstacle in boundary areas of high shear. High velocity gradients produce a violently rotating column of water, similar to a tornado. Kolks are capable of plucking multi-ton blocks of rock and...

s; powerful vortices within the water currents which spin small boulders around, eroding out these rock basins by their abrasive action. These basins are frequently found in streams and rivers with a relatively soft rock substrates such as limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

s and sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

s. The rather unusual and man-made appearance of such depressions has led to various folk-tales becoming associated with them, such as their identification as petrosomatoglyph
Petrosomatoglyph
A petrosomatoglyph is an image of parts of a human or animal body incised in rock. Many were created by Celtic peoples, such as the Picts, Scots, Irish, Cornish, Cumbrians, Bretons and Welsh. These representations date from the Early Middle Ages; others of uncertain purpose date back to megalithic...

s, including knee prints, elbow prints, etc. of saints, heroes, kings or Supernatural
Supernatural
The supernatural or is that which is not subject to the laws of nature, or more figuratively, that which is said to exist above and beyond nature...

 beings.

Formation

Rock-cut basins are formed by the action of fast running water currents that cause small boulders to move in a circular motion or Vortex
Vortex
A vortex is a spinning, often turbulent,flow of fluid. Any spiral motion with closed streamlines is vortex flow. The motion of the fluid swirling rapidly around a center is called a vortex...

. The friction created by these kolks propelling small boulders in a circular motion erodes the natural rock substrate to create concavities called rock-cut basins, that increase in depth and circumference over the years. One or more rounded stones may be found within them, often of varying sizes as these stones also wear away with the physical abrasion effect.

The conditions on the river bed must be just right, so that the 'abrasion stones' remain in approximately one area as they circle, allowing the processes which create the rock-cut basins to occur. During times of heavy flood, river currents provide considerable energy to stones lying on the bottom, as can be witnessed beside many rivers where audible sounds are made by boulders as they are tumbled downstream over the bedrock or as they clash against other boulders. The term Bed load
Bed load
The term bed load or bedload describes particles in a flowing fluid that are transported along the bed. Bed load is complementary to suspended load and wash load.Bed load moves by rolling, sliding, and/or saltating ....

 is used to describe the material carried by a river by being bounced or rolled along its bed.

Folklore

If a rock-cut basin forms on an overhanging ledge at a waterfall or drop in the river level, then a circular holed stone may eventually form. These may have been used in the construction of megalithic monuments, especially tombs. Such holed stones are often associated with folklore as healing stones through which sick children are passed etc., as with the Mên-an-Tol
Mên-an-Tol
The Mên-an-Tol is a small formation of standing stones near the Madron-Morvah road in Cornwall, United Kingdom . It is about 3 miles north west of Madron...

 in Cornwall, where the legend is that passage through the stone will cure a child of Rickets
Rickets
Rickets is a softening of bones in children due to deficiency or impaired metabolism of vitamin D, magnesium , phosphorus or calcium, potentially leading to fractures and deformity. Rickets is among the most frequent childhood diseases in many developing countries...

 (osteomalacia), also Scrofulous as well as spinal conditions in men and women. For centuries, children with rickets were passed naked through the hole in the middle stone nine times, or three times against the sun.
Below the confluence of the North Teign River and the Walla Brook on Dartmoor
Dartmoor
Dartmoor is an area of moorland in south Devon, England. Protected by National Park status, it covers .The granite upland dates from the Carboniferous period of geological history. The moorland is capped with many exposed granite hilltops known as tors, providing habitats for Dartmoor wildlife. The...

 there is a large boulder covered with rock-cut basins, one of which the kolk
Kolk
A kolk is an underwater vortex that is created when rapidly rushing water passes an underwater obstacle in boundary areas of high shear. High velocity gradients produce a violently rotating column of water, similar to a tornado. Kolks are capable of plucking multi-ton blocks of rock and...

s have completely worn through and therefore the stone has an almost perfectly circular hole. The holed stone thus produced is called the 'Tolmen' stone and it has, like others, been the focus for some stories of magical cures and mystical activities. It is said that passing through the hole is a cure for Rheumatism
Rheumatism
Rheumatism or rheumatic disorder is a non-specific term for medical problems affecting the joints and connective tissue. The study of, and therapeutic interventions in, such disorders is called rheumatology.-Terminology:...

 or Arthritis
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....

, whilst children would be cured of whooping-cough
Pertussis
Pertussis, also known as whooping cough , is a highly contagious bacterial disease caused by Bordetella pertussis. Symptoms are initially mild, and then develop into severe coughing fits, which produce the namesake high-pitched "whoop" sound in infected babies and children when they inhale air...

 or Tuberculosis
Tuberculosis
Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...

. Another legend is that if you pass through the hole you will see the future. This may be linked to the belief, recorded elsewhere, that looking through a holed stone gives a person 'second sight', and some later Christian pilgrim sites retain the holed stones which exist in the area so that pilgrims may get a 'glimpse of heaven.' Connected with this was the belief by that looking through a piece of grass made into a circle one was given second sight into the land of the supernatural, making fairies
Fairy
A fairy is a type of mythical being or legendary creature, a form of spirit, often described as metaphysical, supernatural or preternatural.Fairies resemble various beings of other mythologies, though even folklore that uses the term...

 visible, etc.

Passing through the stone may be symbolic of 'rebirth', however it seems that the idea of transferring the disease or condition to the stone was uppermost in the thoughts of the practitioners. To add weight to this idea it has been recorded that sick children were also passed through double-rooted bramble hoops, split ash trees and even holes in the ground.

Faithless wives and wantons were punished and put back on the 'right track' by forcing them first to wash in Cranmere Pool
Cranmere Pool
Cranmere Pool is a small depression in the peat set in the northern half of Dartmoor at SX604858. It is approximately 0.5 km north west of the source of the East Dart and is effectively the head of the West Okement which feeds Meldon reservoir...

 on Dartmoor, then to run round Scorhill circle three times, then they had to pass through the Tolmen stone and finally they went up to the Grey Wethers
Grey Wethers
Grey Wethers consists of a pair of prehistoric stone circles, situated on grassy plateau to the north of Postbridge, Dartmoor, in the United Kingdom....

 stone circle where they knelt and asked forgiveness. If the stones remained standing then all was well, but if their penance was not sincere then a stone would fall and crush them.

Marriages and other binding contracts

Folklore connected with holed stones indicates that they were also used for a ceremony of grasping hands to form a Teltown
Tailtiu
Tailtiu or Tailltiu is the name of a presumed goddess from Irish mythology. Telltown in County Meath, was named for her.-In Irish mythology:...

 marriage, this being a marriage of a year and a day in which either party could return to the spot a year later, renounce the marriage and walk away from the stone and their partner. It is also recorded that hands shaken through a holed stone created unbreakable agreements or contracts.

Details of Rock-cut basins

These photographs were all taken on the Caaf Water
Caaf Water
The Caaf Water in western Scotland nowadays drains from the Caaf Reservoir above Dalry which is fed from Knockendon Reservoir...

, Lynn Glen, Dalry
Dalry, North Ayrshire
Dalry is a small town in the Garnock Valley in Ayrshire, Scotland.-History:Dalry means "King's Valley" or more simply the "Rye Meadow"; indicating a small settlement on the Rye Burn. Its history has signs of early inhabitants in the area...

, Ayrshire, Scotland. The water conditions must be precisely right to create a fully formed kolk as shown by their absence or partial formation in sub-optimal parts of the same river system. Large basins form where the water flow is forceful and many small basins occur where the flow is fast, but the water shallower, such as near the edge of a waterfall. The stone substrate is made of fossiliferous limestone in these photographs.

Druids

Tolmen stones, said to derive from the Cornish
Cornish language
Cornish is a Brythonic Celtic language and a recognised minority language of the United Kingdom. Along with Welsh and Breton, it is directly descended from the ancient British language spoken throughout much of Britain before the English language came to dominate...

 tol (hole) maen (stone), were thought to have been used by Druid
Druid
A druid was a member of the priestly class in Britain, Ireland, and Gaul, and possibly other parts of Celtic western Europe, during the Iron Age....

s for purification and that the wrongdoer was lowered through into the water for 'lustration', a purification rite or cleansing ritual.

Until recently the role of perforated stones may have been twofold; use in fertility or healing rites and as traditional settings for the pledging of vows between couples. The hole in the stone might also represent the female birth canal in the Druid or 'pagan' mind and by passing through it a person was symbolising the act of rebirth and therefore regaining innocence or being cleansed of post-parturition
Childbirth
Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...

 illness, etc.

Witches

The Killoch Burn and glen near Neilston
Neilston
Neilston is a village and parish in East Renfrewshire set in the west central Lowlands of Scotland. It lies in the Levern Valley, southwest of Barrhead, south of Paisley, and south-southwest of Renfrew, at the southwestern fringe of the Greater Glasgow conurbation...

 in East Renfrewshire
East Renfrewshire
East Renfrewshire is one of 32 council areas of Scotland. Until 1975 it formed part of the county of Renfrewshire for local government purposes along with the modern council areas of Renfrewshire and Inverclyde...

, Scotland has become associated with a witch because at low water the numerous 'pot-holes' have worn into one another, giving fantastic shapes. Locals named some of these the witch's floor, hearth, cradle, water-stoup and grave.

Seashore rock-cut basins

All around the coastline of the island of Coll
Coll
Coll is a small island, west of Mull in the Inner Hebrides of Scotland. Coll is known for its sandy beaches, which rise to form large sand dunes, for its corncrakes, and for Breachacha Castle.-Geography and geology:...

 are found rock-cut holes and basins which some people believe them to be prehistoric, related to the cup marks found in many places. Others think that they are bait holes, used for grinding shellfish such as limpets in order to attract fish. Another theory is that they were used for offerings in order to help the safe return of people out at sea. The prehistoric village at Maes Howe had similar sized and shaped basins made from flat stones and possibly sealed with clay, used perhaps for storing bait. Although some of the holes on Coll may be natural, such as this large basin washed by the tide, many others are in locations and are of shapes which show that they are definitely man-made.

Man made basins

Many examples exist, created for a wide range of purposes from the grinding of fish bait to a possible ritual use for the inauguration of kings such as at Dunadd. Bullaun
Bullaun
A bullaun is the term used for the depression in a stone which is often water filled. Natural rounded boulders or pebbles may sit in the bullaun...

s may fall into this category.

External links

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