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75-485: The Scollard Formation consists primarily of sandstones and siltstones, interbedded with mudstones and, in the upper portion, coal seams, as well as minor amounts of bentonite . The sediments were eroded from the Canadian Cordillera , and were transported eastward by river systems and deposited in fluvial channel and floodplain environments. The Scollard is usually classified as the uppermost formation of

150-790: A desiccant due to its adsorption properties. Bentonite desiccants have been successfully used to protect pharmaceutical, nutraceutical, and diagnostic products from moisture degradation and extend shelf life . In most common package environments, bentonite desiccants offer a higher water adsorption capacity than silica gel desiccants. Bentonite complies with the FDA for contact with food and drugs. The application of clay technology by farmers in northeast Thailand, using bentonite clay, has dramatically reversed soil degradation and resulted in greater economic returns, with higher yields and higher output prices. Studies carried out by The International Water Management Institute and partners in 2002–2003 focused on

225-403: A foundry-sand bond in iron and steel foundries . Sodium bentonite is most commonly used for large castings that use dry molds, while calcium bentonite is more commonly used for smaller castings that use "green" or wet molds. Bentonite is also used as a binding agent in the manufacture of iron ore ( taconite ) pellets as used in the steelmaking industry . Bentonite, in small percentages,

300-444: A viscous , shear-thinning material. Most often, bentonite suspensions are also thixotropic , although rare cases of rheopectic behavior have also been reported. At high enough concentrations (about 60 grams of bentonite per litre of suspension , ~6wt.%), bentonite suspensions begin to take on the characteristics of a gel (a fluid with a minimum yield strength required to make it move). Bentonite has been widely used as

375-411: A base for many dermatologic formulas. Granular bentonite is being studied for use in battlefield wound dressings. Bentonite is also sold online and in retail outlets for a variety of indications. Bentoquatam is a bentonate-based topical medication intended to act as a shield against exposure to urushiol , the oil found in plants such as poison ivy or poison oak . Bentonite can also be used as

450-477: A chemical absorbent and container sealant. In 2018, China was the top producer of bentonite, with almost a one-quarter share of the world's production, followed by the United States and India. Total worldwide production was 24,400,000 metric tons of bentonite and 3,400,000 metric tons of fuller's earth. Most high-grade natural sodium bentonite is produced from the western United States in an area between

525-448: A considerably greater swelling capacity than Ca-montmorillonite. Bentonite usually forms from the weathering of volcanic ash in seawater , or by hydrothermal circulation through the porosity of volcanic ash beds, which converts ( devitrification ) the volcanic glass ( obsidian , rhyolite , dacite ) present in the ash into clay minerals. In the mineral alteration process, a large fraction (up to 40–50 wt.%) of amorphous silica

600-405: A factor of eight. This makes bentonite beds unsuitable for building and road construction. However, the swelling property is used to advantage in drilling mud and groundwater sealants. The montmorillonite / smectite making up bentonite is an aluminium phyllosilicate mineral , which takes the form of microscopic platy grains. These give the clay a very large total surface area, making bentonite

675-571: A frequent motif featured in Classical Chinese poetry as an embodiment of sorrowful sentiments due to its autumnal shedding of leaves. The legendary Dry Tree first recorded by Marco Polo was possibly a platanus. According to the legend, it marked the site of the battle between Alexander the Great and Darius III . The German camouflage pattern Platanenmuster ("plane tree pattern"), designed in 1937–1942 by Johann Georg Otto Schick,

750-662: A junior synonym of P. lindeniana ANA clade part of the P. racemosa species aggregate PNA-E clade J.-F.Leroy in a strict sense synonymous with P. mexicana var. interior Nixon & Poole, restricted to Guanajuato , Hidalgo , Querétaro and San Luis Potosí , and of hybrid origin s.str: 1–3 ANA clade syn Platanus occidentalis var. lindeniana part of the P. mexicana species aggregate, synonymous with P. mexicana var. mexicana according Nixon & Poole ANA clade junior synonym of P. lindeniana or distinct species ANA clade ANA clade ANA clade ANA clade PNA-E clade PNA-E clade part of

825-424: A new trench elsewhere on the construction site. In addition, because the colloid is relatively impervious to water, a slurry wall can prevent the seepage of groundwater, which is useful in preventing the further spread of groundwater that has been contaminated by toxic material such as industrial waste. Plasticity is the property of clay that allows it to be manipulated and retain its shape without cracking after

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900-458: A place, and have led to initial suspicion of an attack with an irritant gas. After one such mass attack which affected schoolchildren in classrooms with open windows densely surrounded by plane tees, children had to be admitted to hospital, where they were treated and recovered without ill effects. It was found that the symptoms were due to the fine star-shaped trichomes (hairs) on all parts of platanus trees, which are broken off by strong wind after

975-628: A prolonged dry period. The dust created causes direct irritation and scratchiness in the eyes, throat, and nose, but not the runny nose and itching eyes and nose caused by an allergy . The school incident took place after a dry period, with a fairly high temperature of 29 °C (84 °F), and wind blowing at 50 km/h (31 mph). Protection against platanus cough is provided by avoiding contact and wearing protective glasses and masks under weather conditions promoting release of trichomes. When cleaning in an urban environment, sweeping up fallen leaves and branches can release hairs; cleaning by suction

1050-416: A sealant since it provides a self-sealing, low- permeability barrier. It is used to line the base of landfills to prevent migration of leachate , for confining metal pollutants of groundwater , and for the sealing of subsurface disposal systems for spent nuclear fuel . Similar uses include making slurry walls , waterproofing of below-grade walls, and forming other impermeable barriers, e.g., to seal off

1125-490: A small-bodied one similar to Leptorhynchos have been found. cf. Dromaeosaurus Indeterminate Teeth A dromaeosaurid cf. Paronychodon Indeterminate cf. Richardoestesia cf. R. gilmorei cf. R. isosceles cf. Saurornitholestes cf. S. langstoni Troodon Indeterminate Tyrannosaurus T. rex Torosaurus remains have also been unearthed in this region. Edmontonia remains have also been unearthed here and in

1200-519: A soluble sodium salt such as sodium carbonate to wet bentonite, mixing well, and allowing time for the ion exchange to take place and water to remove the exchanged calcium. Some properties, such as viscosity and fluid loss of suspensions, of sodium-beneficiated calcium bentonite (or sodium-activated bentonite) may not be fully equivalent to those of natural sodium bentonite. For example, residual calcium carbonates (formed if exchanged cations are insufficiently removed) may result in inferior performance of

1275-480: A sufficient hydraulic pressure in the well). Bentonite also curtails drilling fluid invasion by its propensity for aiding in the formation of mud cake . It plays an important role in the earth pressure balance and slurry shield variants of tunnel boring machines . Much of bentonite's usefulness in the drilling and geotechnical engineering industry comes from its unique rheological properties. Relatively small quantities of bentonite suspended in water form

1350-530: A trend between Red Deer and Edmonton . The coal is typically of sub-bituminous B to C rank, although more deeply buried Scollard coals farther to the west reach high-volatile bituminous rank. The Ardley coal has been mined in the Red Deer area, and is currently being mined west of Edmonton to fuel mine-mouth electric power generating stations. The Scollard Formation preserves the remains of vertebrates, especially dinosaurs and, rarely, mammals, as well as

1425-481: A valuable adsorbent . The plates also adhere to each other when wet. This gives the clay a cohesiveness that makes it useful as a binder and as an additive to improve the plasticity of kaolinite clay used for pottery . One of the first findings of bentonite was in the Cretaceous Benton Shale near Rock River, Wyoming . The Fort Benton Group , along with others in stratigraphic succession,

1500-431: A weak negative electrical charge, and this is neutralized by calcium or sodium cations that bind adjacent layers together, with a distance between layers of about 1 nanometer . Because the negative charge is weak, only a fraction of the possible cation sites on the surface of a TOT layer actually contain calcium or sodium. Water molecules can easily infiltrate between sheets and fill the remaining sites. This accounts for

1575-645: A wide range of plant fossils. The Scollard strata span the K-Pg boundary, therefore the lower member of the Scollard provides a record of the last of the dinosaurs, while the upper member records the dawn of the Age of Mammals after the K-Pg extinction event. Plant fossils from the upper, early Paleocene member of the Scollard Formation include species of the ferns Botrychium , Woodwardia and Azolla ;

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1650-429: Is dissolved and leached away, leaving the bentonite deposit in place. Bentonite beds are white or pale blue or green (traces of reduced Fe ) in fresh exposures, turning to a cream color and then yellow, red, or brown (traces of oxidized Fe ) as the exposure is weathered further. As a swelling clay, bentonite has the ability to absorb large quantities of water, which increases its volume by up to

1725-570: Is a genus consisting of a small number of tree species native to the Northern Hemisphere . They are the sole living members of the family Platanaceae . All mature members of Platanus are tall, reaching 30–50 m (98–164 ft) in height. The type species of the genus is the Oriental plane Platanus orientalis . All except for P. kerrii are deciduous , and most are found in riparian or other wetland habitats in

1800-415: Is a high-charge TOT clay mineral, in which negatively charged sheets are bound relatively strongly by more numerous potassium cations , and so it is no longer a swelling clay and has few industrial uses. In contrast to the highly hydrated Na ions which act as "swellers" or "expanders" ions, poorly hydrated K ions behave as "collapsers" when exchanging with Na ions accessible in

1875-489: Is a useful adsorbent of ions in solution, as well as fats and oils. It is the main active ingredient of fuller's earth , probably one of the earliest industrial cleaning agents. It has significantly less swelling capacity than sodium bentonite. Calcium bentonite may be converted to sodium bentonite (termed sodium beneficiation or sodium activation) to exhibit many of sodium bentonite's properties by an ion exchange process. As commonly practiced, this means adding 5–10% of

1950-402: Is added to slow or prevent the settling of the glazes. It can also improve the consistency of application of glazes on porous biscuit-fired ware. Once a certain amount of glaze water has been absorbed by the biscuit the bentonite effectively clogs the pores and resists the absorption of further water resulting in a more evenly thick coat. Bentonite is used in industry and emergency response as

2025-615: Is an anthropogenic hybrid ( cultivar ) between the North American P. occidentalis sensu stricto (ANA clade) and the Mediterranean P. orientalis (PNA-E clade). Widely used as a park tree across the Northern Hemisphere, it frequently backcrosses with both its parents. The following are named species of Platanus ; not all are accepted by all authorities: part of P. mexicana species aggregate, probably

2100-447: Is applied to a type of claystone (a clay rock, not a clay mineral) composed mostly of montmorillonite (a clay mineral from the smectite group). It forms by devitrification of volcanic ash or tuff , typically in a marine environment. This results in a very soft, porous rock that may contain residual crystals of more resistant minerals, and which feels soapy or greasy to the touch. However, in commercial and industrial applications,

2175-478: Is described as low-charge TOT . This means that a crystal of montmorillonite consists of layers, each of which is made up of two T sheets bonded to either side of an O sheet. The T sheets are so called because each aluminium or silicon ion in the sheet is surrounded by four oxygen ions arranged as a tetrahedron. The O sheets are so called because each aluminium ion is surrounded by six oxygen or hydroxyl ions arranged as an octahedron. The complete TOT layer has

2250-562: Is often used in drilling mud for oil and gas wells and boreholes for geotechnical and environmental investigations. The property of swelling also makes sodium bentonite useful as a sealant, since it provides a self-sealing, low permeability barrier. It is used to line the base of landfills , for example. Bentonite is also part of the backfill material used at the nuclear Waste Isolation Pilot Project . Various surface modifications to sodium bentonite improve some rheological or sealing performance in geoenvironmental applications, for example,

2325-459: Is particularly popular for this purpose. The American plane is cultivated sometimes for timber and investigations have been made into its use as a biomass crop. The oriental plane is widely used as an ornamental tree, and also has a number of minor medicinal uses. Most significant aspects of cultural history apply to Platanus orientalis in the Old World. The tree is an important part of

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2400-448: Is preferred. It is not recommended that trees in cities be felled, as they are beneficial; in particular the platanus trichomes act as biofilters for air pollutants. Where there are urban concentrations presenting a risk, seasonal spraying of trees with a solution of apple pectin can prevent the star hair from breaking off. The principal use of these trees is as ornamental trees, especially in urban areas and by roadsides. The London plane

2475-408: Is to the other North American species ( P. mexicana sensu lato , including up to four species: P. chiapaensis, P. lindeniana, P. [×] mexicana sensu stricto , P. oaxacana; P. occidentalis s.l. with two [sub]species: P. occidentalis, P. palmeri ; P. rzedowskii ). The two groups form genetically and morphologically distinct evolutionary lineages ( sister clades ), informally called

2550-418: Is used as an ingredient in commercial and homemade clay bodies and ceramic glazes. It greatly increases the plasticity of clay bodies and decreases settling in glazes, making both easier to work with for most applications. The ionic surface of bentonite has a useful property in making a sticky coating on sand grains. When a small proportion of finely ground bentonite clay is added to hard sand and wetted,

2625-834: The Black Hills of South Dakota and the Bighorn Basin of Wyoming, and the Tokat Resadiye region of Turkey. Mixed sodium/calcium bentonite is mined in Greece , Pakistan , Australia , India , Russia , and Ukraine . In the United States, calcium bentonite is mined primarily in Mississippi and Alabama . Other major locations producing calcium bentonite include New Zealand, Germany, Greece, Turkey, India, and China. Platanus See text Platanus ( / ˈ p l æ t ə n ə s / PLAT -ən-əss )

2700-539: The Edmonton Group , although some early workers included it in the overlying Paskapoo Formation . It is subdivided into an upper, coal-bearing member that consists of the Ardley coal zone, and a lower member that lacks significant coal. Neither member has been formally named. The K-Pg boundary occurs at the base of the lowermost seam of Ardley coal zone, based on dinosaurian and microfloral evidence, as well as

2775-420: The P. racemosa species aggregate PNA-E clade (syn. P. × acerifolia ( Aiton ) Willd. , P. hybrida Brot. ) hybrid of P. occidentalis and P. orientalis interlineage hybrid Planes are susceptible to plane anthracnose ( Apiognomonia veneta ), a fungal disease that can defoliate the trees in some years. The most severe infections are associated with cold, wet spring weather. P. occidentalis and

2850-455: The annulus of a water well , to plug old wells. Bentonite can also be "sandwiched" between synthetic materials to create geosynthetic clay liners (GCLs) for the aforementioned purposes. This technique allows for more convenient transport and installation, and it greatly reduces the volume of bentonite required. It is also used to form barriers around newly planted trees to constrain the growth of its roots: in order to prevent damage to any of

2925-478: The larvae of some Lepidoptera species including Phyllonorycter platani and Setaceous Hebrew Character . In the 21st century a disease, commonly known as Massaria disease, has attacked plane trees across Europe. It is caused by the fungus Splanchnonema platani , and causes large lesions on the upper sides of branches. There have been cases of "platanus cough", symptoms of shortness of breath, coughing, and irritated eyes, which may affect several people in

3000-785: The Paskapoo has been removed by erosion, the Scollard is exposed at surface or covered by Quaternary sediments. The Scollard grades into the Willow Creek Formation in the southern Alberta plains and the Coalspur Formation in the Alberta foothills. The Ardley coal zone in the upper portion is equivalent to the lower part of the Coalspur coal zone of the Coalspur Formation, and is correlated with

3075-399: The active agent is uniformly dispersed and that pesticides and fertilizers are retained on the plants. Bentonite is used as a filler in a wide variety of products, including adhesives , cosmetics , paint , rubber , some greases , and soaps . It also acts as a stabilizer and extender in these products. The property of swelling on contact with water makes sodium bentonite useful as

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3150-494: The addition of polymers. Sodium bentonite can be combined with elemental sulfur as fertilizer prills . These permit slow oxidation of the sulfur to sulfate , a plant nutrient needed for some crops like onions or garlic synthesizing a lot of organo-sulfur compounds, and maintain sulfate levels in rainfall-leached soil longer than either pure powdered sulfur or gypsum . Sulfur/bentonite pads with added organic fertilizers have been used for organic farming. Calcium bentonite

3225-407: The application of locally sourced bentonite clays to degraded soils in the region. These applications were carried out in structured field trials. Applying bentonite clays effectively improved yields of forage sorghum grown under rain-fed conditions. Bentonite application also influenced the prices that farmers received for their crops. Production costs are higher, but due to higher production and

3300-469: The bentonite in geosynthetic liners. Illite is the main clay constituent of potash bentonite (a rock type also known as K-bentonite or potassium bentonite). K-bentonite is a term reserved to volcanic stratigraphy and tephrochronology and is related to the weathered clay rock type only. Illite, the clay mineral, is a potassium -rich phyllosilicate formed from the alteration of smectic clay in contact with groundwater rich in K ions. Illite

3375-597: The clay binds the sand particles into a moldable aggregate known as green sand used for making molds in sand casting . Some river deltas naturally deposit just such a blend of clay silt and sand, creating a natural source of excellent molding sand that was critical to ancient metalworking technology. Modern chemical processes to modify the ionic surface of bentonite greatly intensify this stickiness, resulting in remarkably dough-like yet strong casting sand mixes that stand up to molten metal temperatures. The same effluvial deposition of bentonite clay onto beaches accounts for

3450-405: The conifers Metasequoia and Glyptostrobus ; the monocot Limnobiophyllum (a relative of duckweeds ); and the dicots Cercidiphyllum and Platanus . Crocodylian Albertosuchus , acanthomorph fish Lindoeichthys and unnamed esocid fish are known. Ornithomimus remains have been unearthed here. Two caenagnathid taxa, a large-bodied one similar to Caenagnathus and

3525-651: The dominant clay species is illite (a non-swelling clay). However, in pure clay mineralogy, the term illite is more appropriate than "K-bentonite" (the "altered K-rock") because it is a distinct type of non-swelling clay while the commercial term bentonite implicitly refers to a swelling clay, a smectite (in the European and UK terminology), or a montmorillonite (in the US terminology). Sodium bentonite expands when wet, absorbing as much as several times its dry mass in water. Because of its excellent colloidal properties, it

3600-399: The female flowers become achenes that form an aggregate ball. The fruit is a multiple of achenes (plant systematics, Simpson M. G., 2006). Typically, the core of the ball is 1 cm in diameter and is covered with a net of mesh 1 mm, which can be peeled off. The ball is 2.5–4 cm in diameter and contains several hundred achenes, each of which has a single seed and is conical, with

3675-775: The foothills of the Canadian Rockies to less than 100 metres (330 ft) near the outcrops in south-central Alberta. The Scollard Formation rests disconformably on the Late Cretaceous Battle Formation in the southwestern Alberta plains, on the Wapiti Formation in the northwestern plains, and on the Brazeau Formation in the foothills. It is unconformably overlain by the Paskapoo Formation , and where

3750-494: The incidental use of inducing more rapid clarification of both red and white wines. Bentonite is also considered an effective low-cost adsorbent for the removal of chromium(VI) ions from aqueous solutions (contaminated wastewater). Bentonite is used in a variety of pet care items such as cat litter to absorb pet waste. It is also used to absorb oils and grease. Bentonite is used as an inert carrier for pesticides , fertilizers , and fire retardants . It helps ensure that

3825-415: The interlayers space present between two TOT layers. Dehydrated K ions are preferentially located in between two face-to-face hexagonal cavities formed by six joined silica tetrahedra present at the surface of the basal plane of a TOT layer (see the corresponding figure showing an elementary TOT layer). Because dehydrated, these K ions are sometimes said to form inner-sphere bonds with

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3900-428: The literary scenery of Plato's dialogue Phaedrus . Because of Plato , the tree also played an important role in the scenery of Cicero's De Oratore . The trees also provided the shade under which Aristotle and Plato's famed philosophical schools were held. Handel 's opera Serse has a famous aria , " Ombra mai fu ", which the title character sings in praise of his favorite plane tree. The plane tree has been

3975-738: The lower part of the Ravenscrag Formation of southern Saskatchewan, which is also coal bearing. The Late Cretaceous member is equivalent in age to the Frenchman Formation of Saskatchewan, the Hell Creek Formation of Montana, and the Lance Formation of Wyoming . The coal seams of the Ardley coal zone attain thicknesses in excess of 7 metres (20 ft) in some areas. The zone is present at shallow depths and, in places, exposed at surface, along

4050-402: The name ). Some North American species are called sycamores (especially Platanus occidentalis ), although the term is also used for several unrelated species of trees . The genus name Platanus comes from Ancient Greek πλάτανος , which referred to Platanus orientalis . The flowers are reduced and are borne in balls (globose heads); 3–7 hairy sepals may be fused at the base, and

4125-566: The nearby areas. Ankylosaurus A magniventris Edmontosaurus E. annectens Leptoceratops L. gracilis cf. Pachycephalosaurus P. wyomingensis Thescelosaurus T. edmontonensis Referred to Thescelosaurus sp. Triceratops T. Prorsus Bentonite Bentonite ( / ˈ b ɛ n t ə n aɪ t / BEN -tə-nyte ) is an absorbent swelling clay consisting mostly of montmorillonite (a type of smectite ) which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has

4200-414: The nearby footpaths, parking lots, playgrounds, etc; or any of the surrounding underground infrastructures like the pipes, drainage systems, sewers, etc. Farmers use bentonite to seal retention ponds and line canals. High-purity calcium bentonite is treated with acid for use as a catalyst in cracking heavy petroleum fractions. Bentonite has been prescribed as a bulk laxative , and it is also used as

4275-551: The other American species are the most susceptible, with P. orientalis the most resistant. The hybrid London plane is intermediate in resistance. Ceratocystis platani , a wilt disease , has become a significant problem in recent years in much of Europe. The North American species are mostly resistant to the disease, with which they probably coevolved, while the Old World species are highly sensitive. Other diseases such as powdery mildew occur frequently, but are of lesser importance. Platanus species are used as food plants by

4350-579: The others; recent studies in Mexico have increased the number of accepted species in this subgenus. Within subgenus Platanus , evidence from both chloroplast and nuclear gene sequences suggests that the P. racemosa species complex in Western North America (including P. racemosa , P. gentryi , P. wrightii ) is more closely related to the Eurasian P. orientalis than it

4425-425: The petals are 3–7 and are spatulate . Male and female flowers are separate, but borne on the same plant ( monoecious ). The number of heads in one cluster ( inflorescence ) is indicative of the species (see table below). The male flower has 3–8 stamens ; the female has a superior ovary with 3–7 carpels . Plane trees are wind-pollinated. Male flower-heads fall off after shedding their pollen. After being pollinated,

4500-422: The point attached downward to the net at the surface of the ball. There is also a tuft of many thin stiff yellow-green bristle fibers attached to the base of each achene. These bristles help in wind dispersion of the fruits as in the dandelion . The leaves are simple and alternate. In the subgenus Platanus they have a palmate outline. The base of the leaf stalk (petiole) is enlarged and completely wraps around

4575-557: The presence of the terminal Cretaceous iridium anomaly . The upper member is therefore of early Danian age, while the lower member is of latest Maastrichtian age. The Scollard Formation is present in the subsurface throughout much of southwestern Alberta, and it outcrops extensively along the banks of the Red Deer River in the area of Trochu . Both the upper and lower members thin from west to east. Thicknesses for each member range from more than 300 metres (980 ft) near

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4650-454: The property of adsorbing relatively large amounts of protein molecules from aqueous solutions. Consequently, bentonite is uniquely useful in the process of winemaking , where it is used to remove excessive amounts of protein from white wines . Were it not for this use of bentonite, many or most white wines would precipitate undesirable flocculent clouds or hazes upon exposure to warm temperatures, as these proteins denature . It also has

4725-417: The quality of the food, clay farmers could afford to invest and grow more and better food, compared to nonclay-using farmers. Bentonite slurry walls (also known as diaphragm walls ) are used in construction, where the slurry wall is a trench filled with a thick colloidal mixture of bentonite and water. A trench that would collapse due to the hydraulic pressure in the surrounding soil does not collapse as

4800-496: The shaping force has been removed; clays with low plasticity are known as short or non-plastic . A small amount of bentonite added to clay can increase its plasticity, and hence ease forming of articles by some shaping techniques. However, bentonite typically contains minerals that affect the fired color of the mix, and its swelling properties can make such a mix prone to significant shrinkage and potential cracking as it dries. Ceramic glazes often contain bentonite. The bentonite

4875-406: The slurry balances the hydraulic pressure. Forms for concrete, and rebar, can be assembled in a slurry-filled trench, and then have concrete poured into the form. The liquid concrete being denser displaces the less-dense bentonite slurry and causes the latter to overflow from the trench. This displaced bentonite slurry is then channeled to a recycling unit from which it can subsequently be reused in

4950-530: The splitting of an ancestral lineage into two ( Tree of Life metaphor) but also evolutionary anastomoses : hybridization and introgression. The fossil record of leaves and fruit identifiable to Platanus begins in the Paleocene . Despite the geographic separation between North America and Old World, species from these continents will cross readily resulting in fertile hybrids such as the London plane, which

5025-406: The surrounding oxygen atoms present in the hexagonal cavity hosting them. It means there is no water molecule in between the K ion and the oxygen atoms attached to the silica tetrahedra (T). The main uses of bentonite are in drilling mud and as a binder , purifier, absorbent , and carrier for fertilizers or pesticides . As of around 1990, almost half of the US production of bentonite

5100-530: The swelling property of montmorillonite and other smectite clay minerals. The different types of bentonite are each named after the respective dominant cation. For industrial purposes, two main classes of bentonite are recognized: sodium and calcium bentonite. Sodium bentonite is the more valuable but calcium bentonite is more common. In stratigraphy and tephrochronology , completely devitrified (weathered volcanic glass) ash-fall beds are sometimes also referred to as "K-bentonites" (the illitized clay rock) when

5175-419: The term bentonite is used more generally to refer to any swelling clay composed mostly of smectite clay minerals, which includes montmorillonite. The undifferentiated reference to the weathered volcanic rock for the geologist or to the industrial mixture of swelling clays can be a source of confusion. The montmorillonite making up bentonite is an aluminium phyllosilicate mineral whose crystal structure

5250-631: The variety of plasticity of sand from place to place for building sand castles . Beach sand consisting of only silica and shell grains does not mold well compared to grains coated with bentonite clay. This is why some beaches are much better for building sandcastles than others. The self-stickiness of bentonite allows high-pressure ramming or pressing of the clay in molds to produce hard, refractory shapes, such as model rocket nozzles. Bentonites are used for decolorizing various mineral, vegetable, and animal oils. They are also used for clarifying wine, liquor, cider, beer, mead, and vinegar. Bentonite has

5325-478: The wild, though proving drought-tolerant in cultivation. The hybrid London plane ( Platanus × hispanica ) has proved particularly tolerant of urban conditions, and has been widely planted in London and elsewhere across the temperate world. They are often known in English as planes or plane trees . A formerly used name that is now rare is plantain tree (not to be confused with other, unrelated, species with

5400-411: The young stem bud in its axil. The axillary bud is exposed only after the leaf falls off. The mature bark peels off or exfoliates easily in irregularly shaped patches, producing a mottled, scaly appearance. On old trunks, bark may not flake off, but thickens and cracks instead. There are two subgenera, subgenus Castaneophyllum containing the anomalous P. kerrii , and subgenus Platanus , with all

5475-453: The “ANA clade” (Atlantic North American lineage) and “PNA-E clade” (Pacific North American-European lineage). Both lineages have been affected by reticulate evolutionary processes in the past (ancient or recent hybridization and introgression ): The genus Platanus exemplarily illustrates the concept of a Coral of Life , a species network. Its modern-day species are not only the product of evolutionary dichotomies ( cladogenesis ),

5550-521: Was named after Fort Benton, Montana , in the mid-19th century by Fielding Bradford Meek and F. V. Hayden of the U.S. Geological Survey. Bentonite has since been found in many other locations, including China and Greece (bentonite deposit of the Milos volcanic island in the Aegean Sea ). The total worldwide production of bentonite in 2018 was 20,400,000 metric tons. In geology, the term bentonite

5625-426: Was used as drilling mud. Minor uses include filler , sealant , and catalyst in petroleum refining . Calcium bentonite is sometimes marketed as fuller's earth , whose uses overlap with those of other forms of bentonite. Bentonite is used in drilling mud to lubricate and cool the cutting tools ( drill bit ), to remove cuttings, to stabilize the borehole walls, and to help prevent blowouts (by maintaining

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