Fife is a council area and historic county of Scotland. It is situated between the Firth of Tay and the Firth of Forth, with inland boundaries to Perth and Kinross and Clackmannanshire. By custom it is held to have been one of the major Pictish kingdoms, known as Fib, is still known as the Kingdom of Fife within Scotland. Fife is one of the six local authorities part of the South East Scotland city region, it is a lieutenancy area, was a county of Scotland until 1975. It was occasionally known by the anglicisation Fifeshire in old documents and maps compiled by English cartographers and authors. A person from Fife is known as a Fifer. Fife was a local government region divided into three districts: Dunfermline and North-East Fife. Since 1996 the functions of the district councils have been exercised by the unitary Fife Council. Fife is Scotland's third largest local authority area by population, it has a resident population of just under 367,000, over a third of whom live in the three principal towns of Dunfermline and Glenrothes.
The historic town of St Andrews is located on the northeast coast of Fife. It is well known for the University of St Andrews, one of the most ancient universities in the world and is renowned as the home of golf. Fife, bounded to the north by the Firth of Tay and to the south by the Firth of Forth, is a natural peninsula whose political boundaries have changed little over the ages; the Pictish king list and De Situ Albanie documents of the Poppleton manuscript mention the division of the Pictish realm into seven sub-kingdoms or provinces, one being Fife, though this is now regarded as a medieval invention. The earliest known reference to the common epithet The Kingdom of Fife dates from only 1678, in a proposition that the term derives from the quasi-regal privileges of the Earl of Fife; the notion of a kingdom may derive from a misinterpretation of an extract from Wyntoun. The name is recorded as Fib in A. D. 1150 and Fif in 1165. It was associated with Fothriff; the hill-fort of Clatchard Craig, near Newburgh, was occupied as an important Pictish stronghold between the sixth and eighth centuries AD.
Fife was an important royal and political centre from the reign of King Malcolm III onwards, as the leaders of Scotland moved southwards away from their ancient strongholds around Scone. Malcolm had his principal home in Dunfermline and his wife Margaret was the main benefactor of Dunfermline Abbey; the Abbey replaced Iona as the final resting place of Scotland's royal elite, with Robert I amongst those to be buried there. The Earl of Fife was until the 15th century considered the principal peer of the Scottish realm, was reserved the right of crowning the nation's monarchs, reflecting the prestige of the area. A new royal palace was constructed at Falkland the stronghold of Clan MacDuff, was used by successive monarchs of the House of Stuart, who favoured Fife for its rich hunting grounds. King James VI of Scotland described Fife as a "beggar's mantle fringed wi gowd", the golden fringe being the coast and its chain of little ports with their thriving fishing fleets and rich trading links with the Low Countries.
Wool, linen and salt were all traded. Salt pans heated by local coal were a feature of the Fife coast in the past; the distinctive red clay pan tiles seen on many old buildings in Fife arrived as ballast on trading boats and replaced the thatched roofs. In 1598, King James VI employed a group of 12 men from Fife, who became known as the Fife adventurers, to colonise the Isle of Lewis in an attempt to begin the "civilisation" and de-gaelicisation of the region; this endeavour lasted until 1609 when the colonists, having been opposed by the native population, were bought out by Kenneth Mackenzie, the clan chief of the Mackenzies. Fife became a centre of heavy industry in the 19th century. Coal had been mined in the area since at least the 12th century, but the number of pits increased ten-fold as demand for coal grew in the Victorian period. Rural villages such as Cowdenbeath swelled into towns as thousands moved to Fife to find work in its mines; the opening of the Forth and Tay rail bridges linked Fife with Dundee and Edinburgh and allowed the rapid transport of goods.
Modern ports were constructed at Methil and Rosyth. Kirkcaldy became the world centre for the production of linoleum. Postwar Fife saw the development of Glenrothes. To be based around a coal mine, the town attracted a high number of modern Silicon Glen companies to the region. Fife Council and Fife Constabulary centre their operations in Glenrothes. There are numerous notable historical buildings in Fife, some of which are managed by the National Trust for Scotland or Historic Scotland, they include Dunfermline Abbey, the palace in Culross, Ravenscraig Castle in Kirkcaldy, Dysart Harbour area, Balgonie Castle near Coaltown of Balgonie, Falkland Palace, Kellie Castle near Pittenweem, Hill of Tarvit, St. Andrews Castle, St. Andrews Cathedral and St. Rule's Tower. Fife is represented by five constituency members of the Scottish Parliament and four members of the United Kingdom parliament who are sent to Holyrood and the British Parliament respectively. Following the 2015 General Election, all four of the MPs constituencies were held by the Scottish National Party.
In the 2017 General Election Kirkcaldy and Cowdenbeath was regained by Labour. At the same election, the seat of North East Fife became the closest seat in the country with the SNP holding a majority of 2 over the Liberal Democrats Three of
Kemback is a village and parish in Fife, located 2.5 miles east of Cupar. The present village was developed in the 19th century to house those working the flax mills on the nearby Ceres Burn. From 1681 the minister for the parish was Alexander Edward, until 1689 when he was deprived as a non-juror, he went on to become an architect and landscape architect, working on schemes for Brechin Castle and Hamilton Palace. The civil parish has a population of 558. Kemback G. P. O. Transatlantic Radiophone Station Most hills in the UK were surveyed by the Marconi company during the 1920s. Kemback Hill. In 1927 the General Post Office opened a commercial radiophone service between Kemback and an AT&T site in New Jersey, USA. All that remains is a metal gate into an open field opposite the Kemback graveyard; the field was full of wooden huts, the hill, surrounding areas in the parish, were covered in aerials. The civilian GPO services were moved when line of sight was needed for television transmissions during the 1950s.
Access to most of North Fife was restricted. The Kemback Radio Station was a critical link between Britain and the USA, Sweden and Russia. Classed ULTRA secret, the Kemback station was needed in the event of a retreat from England, the loss of the transatlantic cables by the British forces and an equivalent Transatlantic RadioPhone site at Rugby, England; this eventuality was never needed. Wartime records of the Station's use for radio interception as part of the network of Y-stations for German Enigma machine transmissions are still restricted, have not been released into the public domain, it is unclear. Several staff based in GPO Kemback were transferred to the Far East in the early days of WW2 to Singapore; some were captured, held as prisoners of the Japanese for the remainder of the war. The marshy land around the old and new Kemback churches was drained in the 17th and 18th centuries. A local condition called The Drop or The Ague is recorded in the histories of the Lairds of Kemback, the archive of the Archbishop John Spottiswoode which, although cannot be confirmed, is a form of malaria, similar to that seen in the Somerset levels.
"Kemback". Gazetteer for Scotland. Retrieved 2007-06-08. Colvin, Howard A Biographical Dictionary of British Architects 1600-1840, James Murray, pp. 282–3 New York Times, 1927
Newburgh is a royal burgh and parish of Fife, having a population of 2,171. Newburgh's population has grown about 10% since 1901 when the population was counted at 1904 persons. In 1266 Newburgh was granted burgh status by King Alexander III of Scotland, as a burgh belonging to the Abbot of Lindores. In 1600, Newburgh was given to Patrick Leslie, son of the Earl of Rothes – a powerful Scottish family - and in 1631, Newburgh was made a Royal Burgh by King Charles I. Newburgh is situated on the Firth of Tay, 7 m. N. W. of Ladybank Junction alongside the Edinburgh to Inverness railway line. Newburgh railway station closed in 1955. An active campaign to reopen the station is ongoing and locals are hopeful of success. Fife Scottish used to have a bus depot at East Shore Road but the depot closed in 1991. No buses are now based in Newburgh although the Perth to Glenrothes and Newburgh to St Andrews via Ladybank station still serve the town. Since WW2 many new houses have been built in Newburgh but the population has only increased by about 10%.
Because average house occupancy rates are much lower since the baby boomer years. For some time, Newburgh's industries chiefly consisted of the making of linen, linoleum floorcloth, oilskin fabric and quarrying. There was for many years a net and coble fishery on the Firth Of Tay for salmon and sea trout; the harbour area was used for boatbuilding and the transshipment of cargoes to Perth for vessels of over 200 tons. Raw materials for making linoleum such as cork and linseed oil were imported at the "Factory Pier". Aggregates from the Whin Stone quarry were shipped from Bell's Pier; the main employer from the early 1920's was the linoleum factory known locally as the "Tayside" from The Tayside Floorcloth Company. For many years Newburgh was a prosperous industrial town pulling in workers for the factories from surrounding towns and villages; as linoleum fell out of fashion in the late 60s and 70s attempts were made to produce Vinyl flooring and tiles but the factory was no longer profitable and after changing hands a couple of times it closed in 1980 after a large fire destroyed much of the building.
Situated to the East of the linoleum factory was another factory known locally as "The Oilskin", many women worked there from before The Great War producing oilskin fabric for waterproof clothing such as fishermen's suits and Sou'westers. The factory was taken over by textiles giant Courtaulds in the 1960s but sadly closed some years as demand for the product declined. All of these old industries in Newburgh have gone except quarrying, now the town's biggest single employer. Newburgh is now a dormitory town with many of those of working age travelling outwith the town for work. Perth and Glenrothes are in easy reach by car. Local trades and services including a Health Centre and a Nursing Home and a few shops including a brand new Co-op on the site of the former Ship Inn still provide some local employment. In 2017 a new Whisky distillery opened on the site of Lindores Abbey at the east end of Newburgh; this will produce Lindores Abbey whisky on the site where the earliest reference to "Aqua Vita" a form of Whisky was produced by the monks.
The distillery incorporates a high quality event venue and offers catering and tours of the distillery and Abbey ruins. After many years of lying derelict, the linoleum factory was demolished and cleared and its site is now a recreational waterfront linked to the Mugdrum Park and the Fife Coastal Path. Newburgh was the birthplace in 1823 of Robert Hunter encyclopaedist; the civil parish has a population of 2,171. The plain Georgian town house, with central tower and spire, was built on the south side of the High Street in 1808, it forms a continuous block with the other houses. The Laing Museum and Library was added to the north side of the street in 1894-96. Museum open in summer only. On high ground, about a mile southwest at 56°20′20″N 3°14′44″W, stand the remains of Macduff's Cross, which marks the spot where the clan Macduff in return for its chief's services against Macbeth was granted rights of sanctuary and composition for murder done in hot blood. Denmylne Castle, about a mile south-east of Newburgh at 56°20′39″N 3°12′55″W on the Cupar road, was the home for more than 250 years of the Balfour of Denmylne family, of which the two brothers, the annalist and Lord Lyon, Andrew, founder of the Botanic Garden in Edinburgh, were the most distinguished members.
The castle was abandoned in 1772 when the estate was sold and now stands within a 19th-century steading whose construction will have necessitated the removal of the castle's subsidiary buildings. It has been unroofed for at least 200 years and is in an dangerous state of disrepair. A lintel dated 1620 has been re-used in one of the steading's building, it is a scheduled ancient monument. Lindores Abbey is situated on the East side of the town. Of the Tironensian abbey, founded about 1190 by David, Earl of Huntingdon, brother of William the Lion, there are only fragmentary remains, although the ground plan of the whole structure can still be traced. Best preserved are the south-west gateway through the precinct wall, various discontinuous fragments of the wall itself, part of the east cloister range, including the still vaulted slype, all built of local red sandstone; the monastic church itself had a single aisle on the north side, with aisled north and south transepts, a central tower and a detached western tower or campanile, as at Cam
Sandstone is a clastic sedimentary rock composed of sand-sized mineral particles or rock fragments. Most sandstone is composed of quartz or feldspar because they are the most resistant minerals to weathering processes at the Earth's surface, as seen in Bowen's reaction series. Like uncemented sand, sandstone may be any color due to impurities within the minerals, but the most common colors are tan, yellow, grey, pink and black. Since sandstone beds form visible cliffs and other topographic features, certain colors of sandstone have been identified with certain regions. Rock formations that are composed of sandstone allow the percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are better able to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity. Quartz-bearing sandstone can be changed into quartzite through metamorphism related to tectonic compression within orogenic belts.
Sandstones are clastic in origin. They are formed from cemented grains that may either be fragments of a pre-existing rock or be mono-minerallic crystals; the cements binding these grains together are calcite and silica. Grain sizes in sands are defined within the range of 0.0625 mm to 2 mm. Clays and sediments with smaller grain sizes not visible with the naked eye, including siltstones and shales, are called argillaceous sediments; the formation of sandstone involves two principal stages. First, a layer or layers of sand accumulates as the result of sedimentation, either from water or from air. Sedimentation occurs by the sand settling out from suspension. Once it has accumulated, the sand becomes sandstone when it is compacted by the pressure of overlying deposits and cemented by the precipitation of minerals within the pore spaces between sand grains; the most common cementing materials are silica and calcium carbonate, which are derived either from dissolution or from alteration of the sand after it was buried.
Colors will be tan or yellow. A predominant additional colourant in the southwestern United States is iron oxide, which imparts reddish tints ranging from pink to dark red, with additional manganese imparting a purplish hue. Red sandstones are seen in the Southwest and West of Britain, as well as central Europe and Mongolia; the regularity of the latter favours use as a source for masonry, either as a primary building material or as a facing stone, over other forms of construction. The environment where it is deposited is crucial in determining the characteristics of the resulting sandstone, which, in finer detail, include its grain size and composition and, in more general detail, include the rock geometry and sedimentary structures. Principal environments of deposition may be split between terrestrial and marine, as illustrated by the following broad groupings: Terrestrial environmentsRivers Alluvial fans Glacial outwash Lakes Deserts Marine environmentsDeltas Beach and shoreface sands Tidal flats Offshore bars and sand waves Storm deposits Turbidites Framework grains are sand-sized detrital fragments that make up the bulk of a sandstone.
These grains can be classified into several different categories based on their mineral composition: Quartz framework grains are the dominant minerals in most clastic sedimentary rocks. These physical properties allow the quartz grains to survive multiple recycling events, while allowing the grains to display some degree of rounding. Quartz grains evolve from plutonic rock, which are felsic in origin and from older sandstones that have been recycled. Feldspathic framework grains are the second most abundant mineral in sandstones. Feldspar can be divided into two smaller subdivisions: plagioclase feldspars; the different types of feldspar can be distinguished under a petrographic microscope. Below is a description of the different types of feldspar. Alkali feldspar is a group of minerals in which the chemical composition of the mineral can range from KAlSi3O8 to NaAlSi3O8, this represents a complete solid solution. Plagioclase feldspar is a complex group of solid solution minerals that range in composition from NaAlSi3O8 to CaAl2Si2O8.
Lithic framework grains are pieces of ancient source rock that have yet to weather away to individual mineral grains, called lithic fragments or clasts. Lithic fragments can be any fine-grained or coarse-grained igneous, metamorphic, or sedimentary rock, although the most common lithic fragments found in sedimentary rocks are clasts of volcanic rocks. Accessory minerals are all other mineral grains in a sandstone. Common accessory minerals include micas, olivine and corundum. Many of these accessory grains are more dense than the silicates that
An oak is a tree or shrub in the genus Quercus of the beech family, Fagaceae. There are 600 extant species of oaks; the common name "oak" appears in the names of species in related genera, notably Lithocarpus, as well as in those of unrelated species such as Grevillea robusta and the Casuarinaceae. The genus Quercus is native to the Northern Hemisphere, includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia and North Africa. North America contains the largest number of oak species, with 90 occurring in the United States, while Mexico has 160 species of which 109 are endemic; the second greatest center of oak diversity is China, which contains 100 species. Oaks have spirally arranged leaves, with lobate margins in many species. Many deciduous species are marcescent. In spring, a single oak tree produces small female flowers; the fruit is a nut called an oak nut borne in a cup-like structure known as a cupule. The acorns and leaves contain tannic acid, which helps to guard from insects.
The live oaks are distinguished for being evergreen, but are not a distinct group and instead are dispersed across the genus. The oak tree is a flowering plant. Oaks may be divided into two genera and a number of sections: The genus Quercus is divided into the following sections: Sect. Quercus, the white oaks of Europe and North America. Styles are short; the leaves lack a bristle on their lobe tips, which are rounded. The type species is Quercus robur. Sect. Mesobalanus, Hungarian oak and its relatives of Europe and Asia. Styles long; the section Mesobalanus is related to section Quercus and sometimes included in it. Sect. Cerris, the Turkey oak and its relatives of Europe and Asia. Styles long; the inside of the acorn's shell is hairless. Its leaves have sharp lobe tips, with bristles at the lobe tip. Sect. Protobalanus, the canyon live oak and its relatives, in southwest United States and northwest Mexico. Styles short, acorns mature in 18 months and taste bitter; the inside of the acorn shell appears woolly.
Leaves have sharp lobe tips, with bristles at the lobe tip. Sect. Lobatae, the red oaks of North America, Central America and northern South America. Styles long; the inside of the acorn shell appears woolly. The actual nut is encased in a thin, papery skin. Leaves have sharp lobe tips, with spiny bristles at the lobe; the ring-cupped oaks of eastern and southeastern Asia. Evergreen trees growing 10–40 m tall, they are distinct from subgenus Quercus in that they have acorns with distinctive cups bearing concrescent rings of scales. IUCN, ITIS, Encyclopedia of Life and Flora of China treats Cyclobalanopsis as a distinct genus, but some taxonomists consider it a subgenus of Quercus, it contains about 150 species. Species of Cyclobalanopsis are common in the evergreen subtropical laurel forests which extend from southern Japan, southern Korea, Taiwan across southern China and northern Indochina to the eastern Himalayas, in association with trees of genus Castanopsis and the laurel family. Interspecific hybridization is quite common among oaks but between species within the same section only and most common in the white oak group.
Inter-section hybrids, except between species of sections Mesobalanus, are unknown. Recent systematic studies appear to confirm a high tendency of Quercus species to hybridize because of a combination of factors. White oaks are unable to discriminate against pollination by other species in the same section; because they are wind pollinated and they have weak internal barriers to hybridization, hybridization produces functional seeds and fertile hybrid offspring. Ecological stresses near habitat margins, can cause a breakdown of mate recognition as well as a reduction of male function in one parent species. Frequent hybridization among oaks has consequences for oak populations around the world. Frequent hybridization and high levels of introgression have caused different species in the same populations to share up to 50% of their genetic information. Having high rates of hybridization and introgression produces genetic data that does not differentiate between two morphologically distinct species, but instead differentiates populations.
Numerous hypotheses have been proposed to explain how oak species are able to remain morphologically and ecologically distinct with such high levels of gene flow, but the phenomenon is still a mystery to botanists. The Fagaceae, or beech family, to which the oaks belong, is a slow evolving clade compared to other angiosperms, the patterns of hybridization and introgression in Quercus pose a gre
A canyon or gorge is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic timescales. Rivers have a natural tendency to cut through underlying surfaces wearing away rock layers as sediments are removed downstream. A river bed will reach a baseline elevation, the same elevation as the body of water into which the river drains; the processes of weathering and erosion will form canyons when the river's headwaters and estuary are at different elevations through regions where softer rock layers are intermingled with harder layers more resistant to weathering. A canyon may refer to a rift between two mountain peaks, such as those in ranges including the Rocky Mountains, the Alps, the Himalayas or the Andes. A river or stream and erosion carve out such splits between mountains. Examples of mountain-type canyons are Provo Canyon in Utah or Yosemite Valley in California's Sierra Nevada. Canyons within mountains, or gorges that have an opening on only one side, are called box canyons.
Slot canyons are narrow canyons that have smooth walls. Steep-sided valleys in the seabed of the continental slope are referred to as submarine canyons. Unlike canyons on land, submarine canyons are thought to be formed by turbidity currents and landslides; the word canyon is Spanish in origin, with the same meaning. The word canyon is used in North America while the words gorge and ravine are used in Europe and Oceania, though gorge and ravine are used in some parts of North America. In the United States, place names use canyon in the southwest and gorge in the northeast, with the rest of the country graduating between these two according to geography. In Canada, a gorge is narrow while a ravine is more open and wooded; the military-derived word defile is used in the United Kingdom. Most canyons were formed by a process of long-time erosion from table-land level; the cliffs form because harder rock strata that are resistant to erosion and weathering remain exposed on the valley walls. Canyons are much more common in arid than in wet areas because physical weathering has a more localized effect in arid zones.
The wind and water from the river combine to erode and cut away less resistant materials such as shales. The freezing and expansion of water serves to help form canyons. Water seeps into cracks between the rocks and freezes, pushing the rocks apart and causing large chunks to break off the canyon walls, in a process known as frost wedging. Canyon walls are formed of resistant sandstones or granite. Sometimes large rivers run through canyons as the result of gradual geological uplift; these are called entrenched rivers, because they are unable to alter their course. In the United States, the Colorado River in the Southwest and the Snake River in the Northwest are two examples of tectonic uplift. Canyons form in areas of limestone rock; as limestone is soluble to a certain extent, cave systems form in the rock. When these collapse, a canyon is left, as in the Mendip Hills in Somerset and Yorkshire Dales in Yorkshire, England. A box canyon is a small canyon, shorter and narrower than a river canyon, with steep walls on three sides, allowing access and egress only through the mouth of the canyon.
Box canyons were used in the western United States as convenient corrals, with their entrances fenced. The definition of "largest canyon" is imprecise, because a canyon can be large by its depth, its length, or the total area of the canyon system; the inaccessibility of the major canyons in the Himalaya contributes to their not being regarded as candidates for the biggest canyon. The definition of "deepest canyon" is imprecise if one includes mountain canyons as well as canyons cut through flat plateaus; the Yarlung Tsangpo Grand Canyon, along the Yarlung Tsangpo River in Tibet, is regarded by some as the deepest canyon in the world at 5,500 m. It is longer than the Grand Canyon in the United States. Others consider the Kali Gandaki Gorge in midwest Nepal to be the deepest canyon, with a 6400 m difference between the level of the river and the peaks surrounding it. Vying for deepest canyon in the Americas are the Cotahuasi Canyon and Colca Canyon, in southern Peru. Both have been measured at over 3500 m deep.
The Grand Canyon of northern Arizona in the United States, with an average depth of 1,600 m and a volume of 4.17 trillion cubic metres, is one of the world's largest canyons. It was among the 28 finalists of the New7Wonders of Nature worldwide poll; the largest canyon in Africa is the Fish River Canyon in Namibia. In August 2013, the discovery of Greenland's Grand Canyon was reported, based on the analysis of data from Operation IceBridge, it is located under an ice sheet. At 750 kilometres long, it is believed to be the longest canyon in the world; the Capertee Valley in Australia is reported as being the second largest canyon in the world. Some canyons have notable cultural significance. Evidence of early humanoids has been discovered in Africa's Olduvai Gorge. In the southwestern United States, canyons are important archeologically because of the many cliff-dwellings built in such areas by the ancient Pueblo people who were their first inhabitants; the following list contains only the most notable canyons of the world, arranged by continent and country.
Fish River Canyon Blyde Riv
A fossil is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, petrified wood, coal, DNA remnants; the totality of fossils is known as the fossil record. Paleontology is the study of fossils: their age, method of formation, evolutionary significance. Specimens are considered to be fossils if they are over 10,000 years old; the oldest fossils are around 3.48 billion years old to 4.1 billion years old. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils; the development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host. There are many processes that lead to fossilization, including permineralization and molds, authigenic mineralization and recrystallization, adpression and bioimmuration.
Fossils vary in size from one-micrometre bacteria to dinosaurs and trees, many meters long and weighing many tons. A fossil preserves only a portion of the deceased organism that portion, mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates. Fossils may consist of the marks left behind by the organism while it was alive, such as animal tracks or feces; these types of fossil are called trace ichnofossils, as opposed to body fossils. Some fossils are called chemofossils or biosignatures; the process of fossilization varies according to external conditions. Permineralization is a process of fossilization; the empty spaces within an organism become filled with mineral-rich groundwater. Minerals precipitate from the groundwater; this process can occur in small spaces, such as within the cell wall of a plant cell. Small scale permineralization can produce detailed fossils. For permineralization to occur, the organism must become covered by sediment soon after death, otherwise decay commences.
The degree to which the remains are decayed when covered determines the details of the fossil. Some fossils consist only of skeletal teeth; this is a form of diagenesis. In some cases, the original remains of the organism dissolve or are otherwise destroyed; the remaining organism-shaped hole in the rock is called an external mold. If this hole is filled with other minerals, it is a cast. An endocast, or internal mold, is formed when sediments or minerals fill the internal cavity of an organism, such as the inside of a bivalve or snail or the hollow of a skull; this is a special form of mold formation. If the chemistry is right, the organism can act as a nucleus for the precipitation of minerals such as siderite, resulting in a nodule forming around it. If this happens before significant decay to the organic tissue fine three-dimensional morphological detail can be preserved. Nodules from the Carboniferous Mazon Creek fossil beds of Illinois, USA, are among the best documented examples of such mineralization.
Replacement occurs. In some cases mineral replacement of the original shell occurs so and at such fine scales that microstructural features are preserved despite the total loss of original material. A shell is said to be recrystallized when the original skeletal compounds are still present but in a different crystal form, as from aragonite to calcite. Compression fossils, such as those of fossil ferns, are the result of chemical reduction of the complex organic molecules composing the organism's tissues. In this case the fossil consists of original material, albeit in a geochemically altered state; this chemical change is an expression of diagenesis. What remains is a carbonaceous film known as a phytoleim, in which case the fossil is known as a compression. However, the phytoleim is lost and all that remains is an impression of the organism in the rock—an impression fossil. In many cases, however and impressions occur together. For instance, when the rock is broken open, the phytoleim will be attached to one part, whereas the counterpart will just be an impression.
For this reason, one term covers the two modes of preservation: adpression. Because of their antiquity, an unexpected exception to the alteration of an organism's tissues by chemical reduction of the complex organic molecules during fossilization has been the discovery of soft tissue in dinosaur fossils, including blood vessels, the isolation of proteins and evidence for DNA fragments. In 2014, Mary Schweitzer and her colleagues reported the presence of iron particles associated with soft tissues recovered from dinosaur fossils. Based on various experiments that studied the interaction of iron in haemoglobin with blood vessel tissue they proposed that solution hypoxia coupled with iron chelation enhances the stability and preservation of soft tissue and provides the basis for an explanation for the unforeseen preservation of fossil soft tissues. However, a older study based on eight taxa ranging in time from the Devonian to the Jurassic found that reasonably well-preserved fibrils that represent collagen were preser