A limestone pavement is a natural karst landform consisting of a flat, incised surface of exposed limestone that resembles an artificial pavement. [1] The term is mainly used in the UK and Ireland, where many of these landforms have developed distinctive surface patterning resembling paving blocks. [2] Similar landforms in other parts of the world are known as alvars.
Conditions for limestone pavements are created when an advancing glacier scrapes away overburden and exposes horizontally bedded limestone, with subsequent glacial retreat leaving behind a flat, bare surface. Limestone is slightly soluble in water and especially in acid rain, so corrosive drainage along joints and cracks in the limestone can produce slabs called clints isolated by deep fissures called grikes or grykes [2] (terms derived from a northern English dialect). If the grykes are fairly straight and the clints are uniform in size, the resemblance to man-made paving stones is striking, but they are not necessarily so regular. Limestone pavements that develop beneath a mantle of topsoil usually exhibit more rounded forms.
Limestone pavements can be found in many previously glaciated limestone environments around the world. Notable examples are found in the Yorkshire Dales and Cumbria in Northern England, such as those above Malham Cove, on the side of Ingleborough, and above Grange-over-Sands. [3] They are also found in the Stora Alvaret in Öland, Sweden; in the Burren, County Clare, Ireland, the Great Northern Peninsula on Newfoundland, [4] and in the Désert de Platé, [5] in the French Alps.
Karst is a topography formed from the dissolution of soluble carbonate rocks such as limestone, dolomite, and gypsum. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. More weathering-resistant rocks, such as quartzite, can also occur, given the right conditions.
Weathering is the deterioration of rocks, soils and minerals through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs in situ, and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity.
Pavement or paving may refer to:
A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are also known as shakeholes, and to openings where surface water enters into underground passages known as ponor, swallow hole or swallet. A cenote is a type of sinkhole that exposes groundwater underneath. Sink and stream sink are more general terms for sites that drain surface water, possibly by infiltration into sediment or crumbled rock.
Landforms are categorized by characteristic physical attributes such as their creating process, shape, elevation, slope, orientation, rock exposure, and soil type.
An alvar is a biological environment based on a limestone plain with thin or no soil and, as a result, sparse grassland vegetation. Often flooded in the spring, and affected by drought in midsummer, alvars support a distinctive group of prairie-like plants. Most alvars occur either in northern Europe or around the Great Lakes in North America. This stressed habitat supports a community of rare plants and animals, including species more commonly found on prairie grasslands. Lichen and mosses are common species. Trees and bushes are absent or severely stunted.
A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain. Mesas characteristically consist of flat-lying soft sedimentary rocks capped by a more resistant layer or layers of harder rock, e.g. shales overlain by sandstones. The resistant layer acts as a caprock that forms the flat summit of a mesa. The caprock can consist of either sedimentary rocks such as sandstone and limestone; dissected lava flows; or a deeply eroded duricrust. Unlike plateau, whose usage does not imply horizontal layers of bedrock, e.g. Tibetan Plateau, the term mesa applies exclusively to the landforms built of flat-lying strata. Instead, flat-topped plateaus are specifically known as tablelands.
The Burren is a karst/glaciokarst landscape centred in County Clare, on the west coast of Ireland. It measures around 530 square kilometres (200 sq mi), within the circle made by the villages of Lisdoonvarna, Corofin, Gort and Kinvara. The area includes such natural features as Mullaghmore hill and Ailladie cliffs, and historic monuments such as Poulnabrone dolmen and Caherconnell Stone Fort. The Burren National Park covers a small part of the Burren and is the smallest of the eight National Parks in Ireland, while the adjacent territory, including the Cliffs of Moher, is included in the Burren and Cliffs of Moher Geopark.
The Highland Rim is a geographic term for the area in Tennessee, North Alabama, and Kentucky which surrounds the Central Basin. Geologically, the Central Basin is a dome. The Highland Rim is a cuesta surrounding the basin, and the border where the difference in elevation is sharply pronounced is an escarpment.
Inishmaan is the middle of the three main Aran Islands in Galway Bay, off the west coast of Ireland. It is part of County Galway in the province of Connacht. Inishmaan has a population of about 184, making it the least populous of the Aran Islands. It is one of the most important strongholds of traditional Irish culture. The island is predominantly Irish-speaking and part of the Gaeltacht, though all inhabitants have knowledge of English.
Inisheer is the smallest and most easterly of the three Aran Islands in Galway Bay, Ireland. With 343 residents as of the 2022 census, it is second-most populous of the Arans. Caomhán of Inis Oírr is the island's patron saint. There are five small settlements: Baile Thiar, Chapeltown, Castle Village, Baile an Fhormna and Baile an Lorgain.
A turlough is a seasonal or periodic water body found mostly in limestone karst areas of Ireland, west of the River Shannon. The name comes from the Irish tur, meaning "dry", and loch, meaning "lake". The water bodies fill and empty with the changes in the level of the water table, usually being very low or empty during summer and autumn and full in the winter. As groundwater levels drop the water drains away underground through cracks in the karstic limestone.
Glaciokarst is a geological term that refers to a specific type of karst landscape that been influenced significantly by past glacial activity.
Carboniferous Limestone is a collective term for the succession of limestones occurring widely throughout Great Britain and Ireland that were deposited during the Dinantian Epoch of the Carboniferous Period. These rocks formed between 363 and 325 million years ago. Within England and Wales, the entire limestone succession, which includes subordinate mudstones and some thin sandstones, is known as the Carboniferous Limestone Supergroup.
Mushroom stones, or mushroom rocks, in Ireland are limestone boulders undercut by past weathering regimes. These rocks take the form of solitary sentinels of limestone which still bear the unmistakable marks of long-continued erosion by ice, soil or lapping waves at the edge of lakes which have since vanished or retreated. These stones are sometimes shaped like mushrooms, others have an overhang facing in just one direction, but all are notched and undercut in such a fashion as to suggest prolonged exposure to standing water at some time in the past. The mushroom-shaped stones are produced where the notching forms a fairly even circle around the stone.
Gettlinge is a village in the southwest portion of the island of Öland, Sweden. It is known for its impressive Viking stone ship burial ground. Gettlinge is situated on the western fringe of the Stora Alvaret, a World Heritage Site designated by UNESCO. The site is readily visible from the perimeter highway, Route 136. Gettlinge, as most prehistoric burial sites on Öland, is established on the low-lying ridge, described by Hogan as a geological formation of thickened soil in this alvar region of otherwise extremely thin soil mantle. This ridge was one of the few places on the southern part of the island that had sufficient soil depth for creation of burial mounds.
In geology and geomorphology, a tessellated pavement is a relatively flat rock surface that is subdivided into polygons by fractures, frequently systematic joints, within the rock. This type of rock pavement bears this name because it is fractured into polygonal blocks that resemble tiles of a mosaic floor, or tessellations.
Barren vegetation describes an area of land where plant growth may be sparse, stunted, and/or contain limited biodiversity. Environmental conditions such as toxic or infertile soil, high winds, coastal salt-spray, and climatic conditions are often key factors in poor plant growth and development. Barren vegetation can be categorized depending on the climate, geology, and geographic location of a specific area.
Great Asby Scar is a Site of Special Scientific Interest (SSSI) and National Nature Reserve in Cumbria, UK. It is an area of limestone pavement, south of the village of Great Asby.
The geology of the Yorkshire Dales National Park in northern England largely consists of a sequence of sedimentary rocks of Ordovician to Permian age. The core area of the Yorkshire Dales is formed from a layer-cake of limestones, sandstones and mudstones laid down during the Carboniferous period. It is noted for its karst landscape which includes extensive areas of limestone pavement and large numbers of caves including Britain's longest cave network.
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