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Portland Stone
Portland stone is a limestone geological formation (formally named the Portland Stone Formation) dating to the Tithonian age of the Late Jurassic that is quarried on the Isle of Portland in Dorset, England. The quarries are cut in beds of white-grey limestone separated by chert beds. It has been used extensively as a building stone throughout the British Isles, notably in major public buildings in London such as St Paul's Cathedral and Buckingham Palace. Portland stone is also exported to many countries, being used for example at the United Nations headquarters in New York City. Geology Portland stone formed in a marine environment, on the floor of a shallow, warm, sub-tropical sea probably near land (as evidenced by fossilised driftwood, which is not uncommon). When seawater is warmed by the sun, its capacity to hold dissolved gas is reduced; consequently, dissolved carbon dioxide (CO2) is released into the atmosphere as a gas. Calcium and bicarbonate ions within the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portland Brownstone Quarries
The Portland Brownstone Quarries are a set of historic quarry, quarries in Portland, Connecticut. The brownstone mined from these quarries was an important source for construction in the latter half of the 19th century. The stone from these quarries was used in a number of landmark buildings in Chicago, Boston, New York City, Philadelphia, Baltimore, Washington, D.C., New Haven, Connecticut, and Hartford. The site was listed as a National Historic Landmark, which also placed it on the National Register of Historic Places, on May 16, 2000.Dr. Joanne Kluessendorf (undated) , National Park Service and Early history of the quarry Quarrying on this site began in 1690 by James Stanclift, who contracted with the town of Middletown, Connecticut, Middletown to build stonework in exchange for a deed of land. Commercial quarrying started in 1783 when the Brainerd Quarry Company began operations. During the peak of the brownstone era, more than 1500 workers were employed by the quarr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tithonian
In the geological timescale, the Tithonian is the latest age (geology), age of the Late Jurassic Epoch and the uppermost stage (stratigraphy), stage of the Upper Jurassic Series. It spans the time between 149.2 ±0.7 annum, Ma and 143.1 ±0.6 (million years ago). It is preceded by the Kimmeridgian and followed by the Berriasian (part of the Cretaceous). Stratigraphic definitions The Tithonian was introduced in scientific literature by German stratigrapher Albert Oppel in 1865. The name Tithonian is unusual in geological stage names because it is derived from Greek mythology. Tithonus was the son of Laomedon of Troy and fell in love with Eos, the Greek goddess of dawn. His name was chosen by Albert Oppel for this stratigraphy, stratigraphical stage because the Tithonian finds itself hand in hand with the dawn of the Cretaceous. The base of the Tithonian stage is at the base of the ammonite biozone of ''Hybonoticeras, Hybonoticeras hybonotum''. A global reference profile (a GSSP, G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on Scratch hardness, scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German , a term from the 19th century that came from the Latin word for Lime (material), lime, (genitive ) with the suffix ''-ite'' used to name minerals. It is thus a Doublet (linguistics), doublet of the word ''wikt:chalk, chalk''. When applied by archaeology, archaeologists and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Carbonate
Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skeletons and pearls. Materials containing much calcium carbonate or resembling it are described as calcareous. Calcium carbonate is the active ingredient in agricultural lime and is produced when calcium ions in hard water react with carbonate ions to form limescale. It has medical use as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause hypercalcemia and digestive issues. Chemistry Calcium carbonate shares the typical properties of other carbonates. Notably, it: *reacts with acids, releasing carbonic acid which quickly disintegrates into carbon dioxide and water: : *releases carbon dioxide upon heating, called a thermal decomposition reaction, or calcination (to above 840 °C in the case of ), t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossils of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name comes from Latin ''calx'' " lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and pharmaceuticals for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at normally-encountered concentrations it is odorless. As the source of carbon in the carbon cycle, atmospheric is the primary carbon source for life on Earth. In the air, carbon dioxide is transparent to visible light but absorbs infrared, infrared radiation, acting as a greenhouse gas. Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, and seawater. It is a trace gas Carbon dioxide in Earth's atmosphere, in Earth's atmosphere at 421 parts per million (ppm), or about 0.042% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.028%. Burning fossil fuels is the main cause of these increased concentrations, which are the primary cause of climate change.IPCC (2022Summary for pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United Nations Headquarters
The headquarters of the United Nations (UN) is on of grounds in the Turtle Bay, Manhattan, Turtle Bay neighborhood of Midtown Manhattan in New York City. It borders First Avenue (Manhattan), First Avenue to the west, 42nd Street (Manhattan), 42nd Street to the south, 48th Street (Manhattan), 48th Street to the north, and the East River to the east. Completed in 1952, the complex consists of several structures, including the United Nations Secretariat Building, Secretariat, United Nations Conference Building, Conference, and United Nations General Assembly Building, General Assembly buildings, and the Dag Hammarskjöld Library. The complex was designed by a board of architects led by Wallace Harrison and built by the architectural firm Harrison & Abramovitz, with final projects developed by Oscar Niemeyer and Le Corbusier. The term ''Turtle Bay'' is occasionally used as a metonym for the UN headquarters or for the United Nations as a whole. The headquarters holds the seats of the Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buckingham Palace
Buckingham Palace () is a royal official residence, residence in London, and the administrative headquarters of the monarch of the United Kingdom. Located in the City of Westminster, the palace is often at the centre of state occasions and royal hospitality. It has been a focal point for the British people at times of national rejoicing and mourning. Originally known as Buckingham House, the building at the core of today's palace was a large townhouse (Great Britain), townhouse built for the John Sheffield, 1st Duke of Buckingham and Normanby, Duke of Buckingham and Normanby in 1703 on a site that had been in private ownership for at least 150 years. It was acquired by George III in 1761 as a private residence for Charlotte of Mecklenburg-Strelitz, Queen Charlotte and became known as The Queen's House. During the 19th century it was enlarged by architects John Nash (architect), John Nash and Edward Blore, who constructed three wings around a central courtyard. Buckingham Pala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
St Paul's Cathedral
St Paul's Cathedral, formally the Cathedral Church of St Paul the Apostle, is an Anglican cathedral in London, England, the seat of the Bishop of London. The cathedral serves as the mother church of the Diocese of London in the Church of England. It is on Ludgate Hill at the highest point of the City of London. Its dedication in honour of Paul the Apostle dates back to the original church on this site, founded in AD 604. The high-domed present structure, which was completed in 1710, is a Listed Building, Grade I listed building that was designed in the English Baroque style by Sir Christopher Wren. The cathedral's reconstruction was part of a major rebuilding programme initiated in the aftermath of the Great Fire of London. The earlier Gothic cathedral (Old St Paul's Cathedral), largely destroyed in the Great Fire, was a central focus for medieval and early modern London, including Paul's walk and St Paul's Churchyard, being the site of St Paul's Cross. The cathedral is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Isles
The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebrides, Outer Hebrides, the Northern Isles (Orkney and Shetland), and over six thousand smaller islands. They have a total area of and a combined population of almost 72 million, and include two sovereign states, the Republic of Ireland (which covers roughly five-sixths of Ireland), and the United Kingdom, United Kingdom of Great Britain and Northern Ireland. The Channel Islands, off the north coast of France, are normally taken to be part of the British Isles, even though geographically they do not form part of the archipelago. Under the UK Interpretation Act 1978, the Channel Islands are clarified as forming part of the British Islands, not to be confused with the British Isles. The oldest rocks are 2.7 billion years old and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a precipitation (chemistry), chemical precipitate or a diagenesis, diagenetic replacement, as in petrified wood. Chert is typically composed of the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor, and which contains the silicon skeletal remains of diatoms, Dictyochales, silicoflagellates, and radiolarians. Precambrian cherts are notable for the presence of fossil cyanobacteria. In addition to Micropaleontology, microfossils, chert occasionally contains macrofossils. However, some chert is devoid of any fossils. Chert varies greatly in color, from white to black, but is most often found as gray, brown, grayish brown and light green to rusty redW.L. Roberts, T.J. Campbell, G.R. Rapp Jr., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Geological Survey
The British Geological Survey (BGS) is a partly publicly funded body which aims to advance Earth science, geoscientific knowledge of the United Kingdom landmass and its continental shelf by means of systematic surveying, monitoring and research. The BGS headquarters are in Keyworth, Nottinghamshire, England. Its other centres are located in Edinburgh, Wallingford, Oxfordshire, Wallingford, Cardiff and London. The current tagline of the BGS is: ''Understanding our Earth''. History and previous names The Geological Survey was founded in 1835 by the Board of Ordnance as the Geological Survey of Great Britain, under Directors of the British Geological Survey, directorship of Henry De la Beche. This was the world's first national Geological Survey, geological survey. It remained a branch of the Ordnance Survey for many years. In 1965, it was merged with the Geological Museum and Overseas Geological Surveys, under the name of Institute of Geological Sciences. In 1969, Beris Cox was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
