Elvan
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Elvan
Elvan is a name used in Cornwall and Devon for the native varieties of quartz-porphyry. They are dispersed irregularly in the Devonian series of rocks and some of them make very fine building stones (e.g. Pentewan stone, Polyphant stone and Catacleuse stone). Greenstone is another name for this stone and it is often used for parts of buildings such as doorways so they can be finely carved. Most of the elvan quarries are now disused. Others are quarried in bulk for aggregates commonly used for road-building. More precisely there are two types of rock in this category: one is "white elvan" and the other is "blue elvan". "White elvans" are a group of fine-grained, acid igneous rocks, while "blue elvans" or "greenstones" are various unusual basic igneous rocks. "White elvan" comes from various different locations and is often known as Pentewan stone (or by other names based on the location). Some older descriptions of building stones have called "white elvans" limestone, e.g. in stu ...
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St Germans Church 3
ST, St, or St. may refer to: Arts and entertainment * Stanza, in poetry * Suicidal Tendencies, an American heavy metal/hardcore punk band * Star Trek, a science-fiction media franchise * Summa Theologica, a compendium of Catholic philosophy and theology by St. Thomas Aquinas * St or St., abbreviation of "State", especially in the name of a college or university Businesses and organizations Transportation * Germania (airline) (IATA airline designator ST) * Maharashtra State Road Transport Corporation, abbreviated as State Transport * Sound Transit, Central Puget Sound Regional Transit Authority, Washington state, US * Springfield Terminal Railway (Vermont) (railroad reporting mark ST) * Suffolk County Transit, or Suffolk Transit, the bus system serving Suffolk County, New York Other businesses and organizations * Statstjänstemannaförbundet, or Swedish Union of Civil Servants, a trade union * The Secret Team, an alleged covert alliance between the CIA and American industr ...
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Cornwall
Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic Ocean, to the south by the English Channel, and to the east by the county of Devon, with the River Tamar forming the border between them. Cornwall forms the westernmost part of the South West Peninsula of the island of Great Britain. The southwesternmost point is Land's End and the southernmost Lizard Point. Cornwall has a population of and an area of . The county has been administered since 2009 by the unitary authority, Cornwall Council. The ceremonial county of Cornwall also includes the Isles of Scilly, which are administered separately. The administrative centre of Cornwall is Truro, its only city. Cornwall was formerly a Brythonic kingdom and subsequently a royal duchy. It is the cultural and ethnic origin of the Cornish dias ...
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Devon
Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is a coastal county with cliffs and sandy beaches. Home to the largest open space in southern England, Dartmoor (), the county is predominately rural and has a relatively low population density for an English county. The county is bordered by Somerset to the north east, Dorset to the east, and Cornwall to the west. The county is split into the non-metropolitan districts of East Devon, Mid Devon, North Devon, South Hams, Teignbridge, Torridge, West Devon, Exeter, and the unitary authority areas of Plymouth, and Torbay. Combined as a ceremonial county, Devon's area is and its population is about 1.2 million. Devon derives its name from Dumnonia (the shift from ''m'' to ''v'' is a typical Celtic consonant shift). During the Briti ...
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Quartz-porphyry
Quartz-porphyry, in layman's terms, is a type of volcanic (igneous) rock containing large porphyritic crystals of quartz. These rocks are classified as ''hemi-crystalline acid rocks''. Structure The quartz crystals exist in a fine-grained matrix, usually of micro-crystalline or felsitic structure. In specimens, the quartz appears as small rounded, clear, greyish, vitreous blebs, which are crystals, double hexagonal pyramids, with their edges and corners rounded by resorption or corrosion. Under the microscope they are often seen to contain rounded enclosures of the ground-mass or fluid cavities, which are frequently negative crystals with regular outlines resembling those of perfect quartz crystals. Many of the latter contain liquid carbonic acid and a bubble of gas that may exhibit vibratile motion under high magnifying powers. Variants In addition to quartz there are usually phenocrysts of feldspar, mostly orthoclase, though a varying amount of plagioclase is often prese ...
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Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ...
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Nikolaus Pevsner
Sir Nikolaus Bernhard Leon Pevsner (30 January 1902 – 18 August 1983) was a German-British art historian and architectural historian best known for his monumental 46-volume series of county-by-county guides, ''The Buildings of England'' (1951–74). Life Nikolaus Pevsner was born in Leipzig, Saxony, the son of Anna and her husband Hugo Pevsner, a Russian-Jewish fur merchant. He attended St. Thomas School, Leipzig, and went on to study at several universities, Munich, Berlin, and Frankfurt am Main, before being awarded a doctorate by Leipzig in 1924 for a thesis on the Baroque architecture of Leipzig. In 1923, he married Carola ("Lola") Kurlbaum, the daughter of distinguished Leipzig lawyer Alfred Kurlbaum. He worked as an assistant keeper at the Dresden Gallery between 1924 and 1928. He converted from Judaism to Lutheranism early in his life. During this period he became interested in establishing the supremacy of German modernist architecture after becoming aware of Le ...
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Petrological
Petrology () is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together because they both contain heavy use of chemistry, chemical methods, and phase diagrams. Sedimentary petrology is, on the other hand, commonly taught together with stratigraphy because it deals with the processes that form sedimentary rock. Background Lithology was once approximately synonymous with petrography, but in current usage, lithology focuses on macroscopic hand-sample or outcrop-scale description of rocks while petrography is the speciality that deals with microscopic details. In the petroleum industry, lithology, or more specifically mud logging, is the graphic representation of geological formations being drilled through and drawn on a log called a mud log. As the cuttings are circulated out of the borehole, they are sampled, ...
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Penzance
Penzance ( ; kw, Pennsans) is a town, civil parish and port in the Penwith district of Cornwall, United Kingdom. It is the most westerly major town in Cornwall and is about west-southwest of Plymouth and west-southwest of London. Situated in the shelter of Mount's Bay, the town faces south-east onto the English Channel, is bordered to the west by the fishing port of Newlyn, to the north by the civil parish of Madron and to the east by the civil parish of Ludgvan. The civil parish includes the town of Newlyn and the villages of Mousehole, Paul, Gulval, and Heamoor. Granted various royal charters from 1512 onwards and incorporated on 9 May 1614, it has a population of 21,200 (2011 census). Penzance's former main street Chapel Street has a number of interesting features, including the Egyptian House, The Admiral Benbow public house (home to a real life 1800s smuggling gang and allegedly the inspiration for ''Treasure Island''s "Admiral Benbow Inn"), the Union Hotel (includi ...
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Neolithic Greenstone Axe Roughout (plan) (FindID 258401)
The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts of the world. This "Neolithic package" included the introduction of farming, domestication of animals, and change from a hunter-gatherer lifestyle to one of settlement. It began about 12,000 years ago when farming appeared in the Epipalaeolithic Near East, and later in other parts of the world. The Neolithic lasted in the Near East until the transitional period of the Chalcolithic (Copper Age) from about 6,500 years ago (4500 BC), marked by the development of metallurgy, leading up to the Bronze Age and Iron Age. In other places the Neolithic followed the Mesolithic (Middle Stone Age) and then lasted until later. In Ancient Egypt, the Neolithic lasted until the Protodynastic period, 3150 BC.Karin Sowada and Peter Grave. Egypt in the ...
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Geology Of Cornwall
The geology of Cornwall, England, is dominated by its granite backbone, part of the Cornubian batholith, formed during the Variscan orogeny. Around this is an extensive metamorphic aureole (known locally as killas) formed in the mainly Devonian slates that make up most of the rest of the county. There is an area of sandstone and shale of Carboniferous age in the north east, and the Lizard peninsula is formed of a rare section of uplifted oceanic crust. Coasts Cornwall forms the tip of the south-west peninsula of the island Great Britain, and is therefore exposed to the full force of the prevailing winds that blow in from the Atlantic Ocean. The coastline is composed mainly of resistant rocks that give rise in many places to impressive cliffs. The north and south coasts have different characteristics. The north coast is more exposed and therefore has a wilder nature. The prosaically-named ''High Cliff'', between Boscastle and St Gennys, is the highest sheer-drop cliff in Corn ...
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Geology Of Devon
Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devon is a coastal county with cliffs and sandy beaches. Home to the largest open space in southern England, Dartmoor (), the county is predominately rural and has a relatively low population density for an English county. The county is bordered by Somerset to the north east, Dorset to the east, and Cornwall to the west. The county is split into the non-metropolitan districts of East Devon, Mid Devon, North Devon, South Hams, Teignbridge, Torridge, West Devon, Exeter, and the unitary authority areas of Plymouth, and Torbay. Combined as a ceremonial county, Devon's area is and its population is about 1.2 million. Devon derives its name from Dumnonia (the shift from ''m'' to ''v'' is a typical Celtic consonant shift). During the British I ...
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