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Pentire Head
Pentire Head ( kw, Penn Tir, meaning "headland") is a headland and peninsula on the Atlantic coast in North Cornwall, England, and is about one mile square. The headland projects north-west with Pentire Point at its north-west corner and The Rumps promontory at its north-east corner. Etymology The origin of the name is from Cornish ''penn'' (head) and ''tir'' (land): another headland with the name Pentire is further west near Crantock. Geography Pentire Point and Stepper Point stand at either side of the mouth of the River Camel estuary (Pentire to the north-east, Stepper to the south-west). To the south of Pentire Point is the small seaside resort of Polzeath. The coastline around the headland is owned by the National Trust, although the bulk of the headland itself is let to Pentire Farm. The entire headland forms the Pentire Peninsula Site of Special Scientific Interest, designated for its geology and flora and fauna including nationally rare plants. Important examples noted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornish Language Partnership
The Cornish Language Partnership ( kw, Keskowethyans an Taves Kernewek , ) is a representative body that was set up in Cornwall, England, UK in 2005 to promote and develop the use of the Cornish language. It is a public and voluntary sector partnership and consists of representatives from various Cornish language societies, Cornish cultural and economic organisations and local government in Cornwall. The organisation is part-funded by the European Union's Objective One programme, the United Kingdom government's Department for Communities and Local Government and Cornwall Council. The Partnership is the chief regulator of the Standard Written Form of Cornish, an orthography that was published in 2008 with the intention of uniting the previous conflicting orthographies, and for use on road signs, in official documents, and in school examinations. Organisations represented * Agan Tavas * Cussel an Tavas Kernuak * Kesva an Taves Kernewek * Kowethas an Yeth Kernewek See also * ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate subphylum Vertebrata. Familiar examples of invertebrates include arthropods, mollusks, annelids, echinoderms and cnidarians. The majority of animal species are invertebrates; one estimate puts the figure at 97%. Many invertebrate taxa have a greater number and variety of species than the entire subphylum of Vertebrata. Invertebrates vary widely in size, from 50 μm (0.002 in) rotifers to the 9–10 m (30–33 ft) colossal squid. Some so-called invertebrates, such as the Tunicata and Cephalochordata, are more closely related to vertebrates than to other invertebrates. This makes the invertebrates paraphyletic, so the term has little meaning in taxonomy. Etymology The word "invertebrate" comes from the Latin word ''vertebra'', whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seabirds
Seabirds (also known as marine birds) are birds that are adaptation, adapted to life within the marine (ocean), marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding ecological niche, niches have resulted in similar adaptations. The first seabirds evolved in the Cretaceous geological period, period, and modern seabird families emerged in the Paleogene. In general, seabirds live longer, Reproduction, breed later and have fewer young than other birds do, but they invest a great deal of time in their young. Most species nest in Bird colony, colonies, which can vary in size from a few dozen birds to millions. Many species are famous for undertaking long annual bird migration, migrations, crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Seabirds can be hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Trust
The National Trust, formally the National Trust for Places of Historic Interest or Natural Beauty, is a charity and membership organisation for heritage conservation in England, Wales and Northern Ireland. In Scotland, there is a separate and independent National Trust for Scotland. The Trust was founded in 1895 by Octavia Hill, Sir Robert Hunter and Hardwicke Rawnsley to "promote the permanent preservation for the benefit of the Nation of lands and tenements (including buildings) of beauty or historic interest". It was given statutory powers, starting with the National Trust Act 1907. Historically, the Trust acquired land by gift and sometimes by public subscription and appeal, but after World War II the loss of country houses resulted in many such properties being acquired either by gift from the former owners or through the National Land Fund. Country houses and estates still make up a significant part of its holdings, but it is also known for its protection of wild lands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ("native silver"), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc Refining (metallurgy), refining. Silver has long been valued as a precious metal. Silver metal is used in many bullion coins, sometimes bimetallism, alongside gold: while it is more abundant than gold, it is much less abundant as a native metal. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". As one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases, and it tends to form covalent bonds. Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited to organolead compounds. Like the lighter members of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lode
In geology, a lode is a deposit of metalliferous ore that fills or is embedded in a fissure (or crack) in a rock formation or a vein of ore that is deposited or embedded between layers of rock. The current meaning (ore vein) dates from the 17th century, being an expansion of an earlier sense of a "channel, watercourse" in late Middle English, which in turn is from the 11th-century meaning of ''lode'' as a ‘course, way’. The generally accepted hydrothermal model of lode deposition posits that metals dissolved in hydrothermal solutions (hot spring fluids) deposit the gold or other metallic minerals inside the fissures in the pre-existing rocks. Lode deposits are distinguished primarily from placer deposits, where the ore has been eroded out from its original depositional environment and redeposited by sedimentation. A third process for ore deposition is as an evaporite. A stringer lode is one in which the rock is so permeated by small veinlets that rather than mining the v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adit
An adit (from Latin ''aditus'', entrance) is an entrance to an underground mine which is horizontal or nearly horizontal, by which the mine can be entered, drained of water, ventilated, and minerals extracted at the lowest convenient level. Adits are also used to explore for mineral veins. Construction Adits are driven into the side of a hill or mountain, and are often used when an ore body is located inside the mountain but above the adjacent valley floor or coastal plain. In cases where the mineral vein outcrops at the surface, the adit may follow the lode or vein until it is worked out, in which case the adit is rarely straight. The use of adits for the extraction of ore is generally called drift mining. Adits can only be driven into a mine where the local topography permits. There will be no opportunity to drive an adit to a mine situated on a large flat plain, for instance. Also if the ground is weak, the cost of shoring up a long adit may outweigh its possible advantage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shaft Mining
Shaft mining or shaft sinking is the action of excavating a mine shaft from the top down, where there is initially no access to the bottom. Shaft (civil engineering), Shallow shafts, typically sunk for civil engineering projects, differ greatly in execution method from deep shafts, typically sunk for mining projects. Shaft sinking is one of the most difficult of all mine development methods: restricted space, gravity, groundwater and specialized procedures make the task quite formidable. Shafts may be sunk by conventional drill and blast or mechanised means. Historically, mine shaft sinking has been among the most dangerous of all the mining occupations and the preserve of mining contractors called sinker (mining), sinkers. Today shaft sinking contractors are concentrated in Canada, Germany, China and South Africa. The modern shaft sinking industry is gradually shifting further towards greater mechanisation. Recent innovations in the form of full-face shaft boring (akin to a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehnite
Prehnite is an inosilicate of calcium and aluminium with the formula: Ca2Al(AlSi3O10)(OH)2. Limited Fe3+ substitutes for aluminium in the structure. Prehnite crystallizes in the orthorhombic crystal system, and most often forms as stalactitic or botryoidal aggregates, with only just the crests of small crystals showing any faces, which are almost always curved or composite. Very rarely will it form distinct, well-individualized crystals showing a square-like cross-section, including those found at the Jeffrey Mine in Asbestos, Quebec, Canada. Prehnite is brittle with an uneven fracture and a vitreous to pearly luster. Its hardness is 6-6.5, its specific gravity is 2.80-2.90 and its color varies from light green to yellow, but also colorless, blue, pink or white. In April 2000, rare orange prehnite was discovered in the Kalahari Manganese Fields, South Africa. Prehnite is mostly translucent, and rarely transparent. Though not a zeolite, prehnite is found associated with minerals suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolerite
Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). ''Diabase'' is the preferred name in North America, while ''dolerite'' is the preferred name in the rest of the English-speaking world, where sometimes the name ''diabase'' refers to altered dolerites and basalts. Some geologists prefer to avoid confusion by using the name ''microgabbro''. The name ''diabase'' comes from the French ', and ultimately from the Greek - meaning "act of crossing over, transition". Petrography Diabase normally has a fine but visible texture of euhedral lath-shaped plagioclase crystals (62%) set in a finer matrix of clinopyroxene, typically augite (20–29%), with minor olivine (3% up to 12% in olivine diabase), magnetite (2%), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pillow Lavas
Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava underwater, or ''subaqueous extrusion''. Pillow lavas in volcanic rock are characterized by thick sequences of discontinuous pillow-shaped masses, commonly up to one meter in diameter. They form the upper part of Layer 2 of normal oceanic crust. Composition Pillow lavas are commonly of basaltic composition, although pillows formed of komatiite, picrite, boninite, basaltic andesite, andesite, dacite or even rhyolite are known. In general, the more felsic the composition (richer in silica - resulting in an Intermediate composition), the larger the pillows, due to the increase in viscosity of the erupting lava. Occurrence They occur wherever lava is extruded underwater, such as along marine hotspot volcano chains and the constructive plate boundaries of mid-ocean ridges. As new oceanic crust is formed, thick sequences of pillow lavas are erupted at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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