Clunch

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Flint and the pale stone, clunch used together in a checkerboard pattern on the wall of the side chapel at St Michael's Church, Mickleham, Surrey. St Michael's Church, Old London Road, Mickleham (NHLE Code 1028835) (Chequerboard Wall of Side Chapel).JPG
Flint and the pale stone, clunch used together in a checkerboard pattern on the wall of the side chapel at St Michael's Church, Mickleham, Surrey.

Clunch is a traditional building material of chalky limestone rock used mainly in eastern England and Normandy. Clunch distinguishes itself from archetypal forms of limestone by being softer in character when cut, such as resembling chalk in lower density, or with minor clay-like components.

Contents

Use

It has been used in a wide variety of shapes such as irregular lumps picked from the topsoil of certain fields, or more commonly blocks quarried by being cut from the bedrock in regular-shaped (ashlar) building blocks. If in the first form it can be bedded in a ramshackle manner (as rubble masonry); if in the second then laid in courses. In either case, mortar is often used between stones to form walls.

Properties

The stone is a chalk from the Lower Chalk of the Cretaceous age, the period of geological time approximately 145 – 66 million years ago. It is greyish-white to light beige in colour, often with a greenish tinge. The latter is due to the presence of glauconite, the potassium and iron aluminium silicate mineral that is also found in Kentish Ragstone. [1] The stone has a gritty texture due to the frequent presence of shell fossils. This stone has been quarried at Totternhoe Quarry in Dunstable, Bedfordshire by H. G. Clarke & Son since 1920. [2]

It is particularly soft when quarried and subject to chemical and wind erosion as exposed material, i.e. when unrendered in paint, stucco or cement. It can be cut by a saw when in its softer state; when it has been quarried out of the ground it still contains a large amount of water. [3] When the stone dries out it becomes harder, and is not as easy to cut.

Clunch is generically a soft limestone. It can be rich in iron-bearing clays or be very fine and white in effect just chalk. It is used in various parts of East Anglia, where more durable stone is uncommon, and can be seen frequently in and around Thetford mostly now for property boundary walls where not a long-lasting material, but it is also used for some building walls, especially in traditional agricultural buildings.

In Ely Cathedral it can be seen in some interior locations. The nearby village of Burwell has its civil parish magazine named after the building material. [4] It is found in the village of Seale in Surrey and in Farnham. [5]

Inferior meaning

The term has been sometimes used more generically, in other parts of England for any soft and aggregate-based vernacular building stone which has been used as a cheaper, inferior substitute for stronger stone.

See also

Related Research Articles

Flint Cryptocrystalline form of the mineral quartz

Flint is a sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start fires.

Chalk Soft, white, porous sedimentary rock made of calcium carbonate

Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of sub-microscopic plankton which had fallen to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel.

Quarry A place from which a geological material has been excavated from the ground

A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environmental impact.

Portland stone Limestone quarried on the Isle of Portland, Dorset, England

Portland Stone or Portland Stone Formation is a limestone formation from the Tithonian stage of the Jurassic period quarried on the Isle of Portland, Dorset, England. The quarries are cut in beds of white-grey limestone separated by chert beds. It has been used extensively as a building stone throughout the British Isles, notably in major public buildings in London such as St Paul's Cathedral and Buckingham Palace. Portland Stone is also exported to many countries—being used for example in the United Nations headquarters building in New York City.

Earth materials

Earth materials include minerals, rocks, soil and water. These are the naturally occurring materials found on Earth that constitute the raw materials upon which our global society exists. Earth materials are vital resources that provide the basic components for life, agriculture and industry. Earth materials can also include metals and precious rocks.

Mortar (masonry)

Mortar is a workable paste which hardens to bind building blocks such as stones, bricks, and concrete masonry units, to fill and seal the irregular gaps between them, spread the weight of them evenly, and sometimes to add decorative colors or patterns to masonry walls. In its broadest sense, mortar includes pitch, asphalt, and soft mud or clay, as used between mud bricks. The word "mortar" comes from Latin mortarium, meaning crushed.

Plaster General term for a broad range of building and sculpture materials

Plaster is a building material used for the protective or decorative coating of walls and ceilings and for moulding and casting decorative elements. In English, "plaster" usually means a material used for the interiors of buildings, while "render" commonly refers to external applications. Another imprecise term used for the material is stucco, which is also often used for plasterwork that is worked in some way to produce relief decoration, rather than flat surfaces.

Building material Material which is used for construction purposes

Building material is material used for construction. Many naturally occurring substances, such as clay, rocks, sand and wood, even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and some less synthetic. The manufacturing of building materials is an established industry in many countries and the use of these materials is typically segmented into specific specialty trades, such as carpentry, insulation, plumbing, and roofing work. They provide the make-up of habitats and structures including homes.

Stone carving The act of shaping stone materials

Stone carving is an activity where pieces of rough natural stone are shaped by the controlled removal of stone. Owing to the permanence of the material, stone work has survived which was created during our prehistory or past time.

Geology of Dorset

Dorset is a county in South West England on the English Channel coast. Covering an area of 2,653 square kilometres (1,024 sq mi); it borders Devon to the west, Somerset to the north-west, Wiltshire to the north-east, and Hampshire to the east. The great variation in its landscape owes much to the underlying geology which includes an almost unbroken sequence of rocks from 200 Ma to 40 Ma and superficial deposits from 2 Ma to the present. In general the oldest rocks appear in the far west of the county, with the most recent (Eocene) in the far east. Jurassic rocks also underlie the Blackmore Vale and comprise much of the coastal cliff in the west and south of the county; and although younger Cretaceous rocks crown some of the highpoints in the west, they are mainly to be found in the centre and east of the county.

Natural building

A natural building involves a range of building systems and materials that place major emphasis on sustainability. Ways of achieving sustainability through natural building focus on durability and the use of minimally processed, plentiful or renewable resources, as well as those that, while recycled or salvaged, produce healthy living environments and maintain indoor air quality. Natural building tends to rely on human labor, more than technology. As Michael G. Smith observes, it depends on "local ecology, geology and climate; on the character of the particular building site, and on the needs and personalities of the builders and users."

Lime (material) Calcium mineral

Lime is a calcium-containing inorganic mineral composed primarily of oxides, and hydroxide, usually calcium oxide and/ or calcium hydroxide. It is also the name for calcium oxide which occurs as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The word lime originates with its earliest use as building mortar and has the sense of sticking or adhering.

Hamstone Building stone from Somerset

Hamstone is the name given to a honey-coloured building stone from Ham Hill, Somerset, England. It is a well-cemented medium to coarse grained limestone characterised by marked bedding planes of clay inclusions and less well-cemented material which weather differentially to give exposed blocks a characteristic furrowed appearance. In origin, Hamstone is a Jurassic limestone from the Toarcian, or Upper Lias, stage.

Jerusalem stone

Jerusalem stone is a name applied to various types of pale limestone, dolomite and dolomitic limestone, common in and around Jerusalem that have been used in building since ancient times. One of these limestones, meleke, has been used in many of the region's most celebrated structures, including the Western Wall.

Totternhoe Stone

Totternhoe Stone is a relatively hard chalk outcropping in the middle of the Lower Chalk in the Chiltern Hills in Hertfordshire, Buckinghamshire, Bedfordshire and Cambridgeshire, England. Geologically, it is located in the upper part of the Cenomanian stage of the Cretaceous.

Meleke

Meleke, also transliterated melekeh or malaki, is a lithologic type of white, coarsely-crystalline, thickly bedded-limestone found in the Judean Hills in Israel and the West Bank. It has been used in the traditional architecture of Jerusalem since ancient times, especially in Herodian architecture. Though it is often popularly referred to as Jerusalem stone, that phrase can refer to a number of different types of stone found and used in or associated with Jerusalem.

Geography of Dorset

Dorset is a county located in the middle of the south coast of England. It lies between the latitudes 50.512°N and 51.081°N and the longitudes 1.682°W and 2.958°W, and occupies an area of 2,653 km². It spans 90 kilometres (56 mi) from east to west and 63 kilometres (39 mi) from north to south.

Fencepost limestone

Fencepost limestone, Post Rock limestone, or Stone Post is a stone bed in the Great Plains notable for its historic use as fencing and construction material in north-central Kansas resulting in unique cultural expression. The source of this stone is the topmost layer of the Greenhorn Limestone formation. It is a regional marker bed as well as a valued construction material of the late 19th and early 20th centuries in Kansas. This stone was very suitable for early construction in treeless settlements and it adds a notable rust orange tint to the region's many historic stone buildings. But the most famous use is seen in the countless miles of stone posts lining country roads and highways. This status gives rise to such regional appellations as Stone Post Country, Post Rock Scenic Byway, and The Post Rock Capital of Kansas. This rustic quality finds Fencepost limestone still used in Kansas landscaping today.

References

  1. "Cambridgeshire Clunch". Projects.bre.co.uk. Retrieved 2013-06-20.
  2. H. G. Clarke and Son
  3. "Gone for Clunch". BBC. 2006-06-29. Retrieved 2013-06-20.
  4. "Burwell Parish magazine". Burwell.co.uk. Retrieved 2013-06-20.
  5. Guildford Borough Council Advisory Leaflet [ dead link ]