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Akilia
Akilia Island is an island in southwestern Greenland, about 22 kilometers south of Nuuk (Godthåb), at . Akilia is the location of a rock formation that has been proposed to contain the oldest known sedimentary rocks on Earth, and perhaps the oldest evidence of life, life on Earth.Mojzsis, SJ, Arrhenius, G, McKeegan, KD, Harrison, TM, Nutman, AP, Friend, CRL (1996) ''Evidence for life on Earth before 3,800 million years ago''. Nature, v. 384, p. 55-59 Geology The rocks in question are part of a metamorphism, metamorphosed supracrustal sequence located at the south-western tip of the island. The sequence has been dated as no younger than 3.85 billion years old - that is, in the Hadean eon - based on the age of an igneous band that cuts the rock. The supracrustal sequence contains layers rich in Iron(II) oxide, iron and Silicon dioxide, silica, which are variously interpreted as banded iron formation, chemical sediments from Black smoker, submarine hot springs, or Hydrothermal circ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Islands Of Greenland
The following is an alphabetical list of the islands of Greenland. Many of these islands have both a Kalaallisut language name and a European language name. Islands and archipelagoes * Aaluik *Aasiaat Archipelago * Achton Friis Islands * Aggas *Akilia *Alluttoq Island *Aluk Island *Ammassalik Island * Anoraliuirsoq *Appat Island *Apusiaajik Island *ATOW1996 *Beaumont Island (Greenland) *Bjorne Island *Bjorne Islands * Bjornesk Island *Bonsall Islands *Bontekoe Island *Borup Island *Brainard Island * Bushnan Island *Cape Farewell Archipelago ** Annikitsoq **Avallersuaq **Egger Island **Ikeq Island ** Nunarsuaq (Nunarssuak) ** Pamialluk ** Qernertoq **Qunnerit **Sammisoq ** Saningassoq **Walkendorff Island *Carey Islands *Castle Island, Greenland *Clavering Island * Crown Prince Islands *Crozier Island *Danmark Island *Danske Islands * Deception Island (Greenland) * Diego's Island * Djævleøen * Dog's Island *Edward Island * Elison Island *Ella Island * Ensomheden *Finsch Islan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Origin Of Life
In biology, abiogenesis (from a- 'not' + Greek bios 'life' + genesis 'origin') or the origin of life is the natural process by which life has arisen from non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to living entities on Earth was not a single event, but an evolutionary process of increasing complexity that involved the formation of a habitable planet, the prebiotic synthesis of organic molecules, molecular self-replication, self-assembly, autocatalysis, and the emergence of cell membranes. Many proposals have been made for different stages of the process. The study of abiogenesis aims to determine how pre-life chemical reactions gave rise to life under conditions strikingly different from those on Earth today. It primarily uses tools from biology and chemistry, with more recent approaches attempting a synthesis of many sciences. Life functions through the specialized chemistry of carbon and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Islands Of Greenland
The following is an alphabetical list of the islands of Greenland. Many of these islands have both a Kalaallisut language name and a European language name. Islands and archipelagoes * Aaluik * Aasiaat Archipelago * Achton Friis Islands * Aggas *Akilia *Alluttoq Island *Aluk Island * Ammassalik Island * Anoraliuirsoq *Appat Island *Apusiaajik Island *ATOW1996 *Beaumont Island (Greenland) * Bjorne Island *Bjorne Islands * Bjornesk Island * Bonsall Islands *Bontekoe Island *Borup Island * Brainard Island * Bushnan Island *Cape Farewell Archipelago ** Annikitsoq ** Avallersuaq **Egger Island ** Ikeq Island ** Nunarsuaq (Nunarssuak) ** Pamialluk ** Qernertoq **Qunnerit **Sammisoq ** Saningassoq **Walkendorff Island *Carey Islands * Castle Island, Greenland *Clavering Island * Crown Prince Islands *Crozier Island *Danmark Island *Danske Islands * Deception Island (Greenland) * Diego's Island * Djævleøen * Dog's Island * Edward Island * Elison Island *Ella Island * Ensomheden *Fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Smoker
A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspots. Hydrothermal deposits are rocks and mineral ore deposits formed by the action of hydrothermal vents. Hydrothermal vents exist because the earth is both geologically active and has large amounts of water on its surface and within its crust. Under the sea, they may form features called black smokers or white smokers. Relative to the majority of the deep sea, the areas around hydrothermal vents are biologically more productive, often hosting complex communities fueled by the chemicals dissolved in the vent fluids. Chemosynthetic bacteria and Archaea form the base of the food chain, supporting diverse organisms, including giant tube worms, clams, limpets and shrimp. Active hydrothermal vents are thought to exist on Jupiter's moon Europa an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Greenland
Greenland is the largest island on Earth. Only one-fifth of its surface area is exposed bedrock, the rest being covered by ice. The exposed surface is approximately 410,000 km2. The geology of Greenland is dominated by crystalline rocks of the Precambrian Shield."Greenland Geology." ''Geological Survey of Denmark and Greenland''. 20 June 2003 (retrieved 26 Dec 2010) The crystalline rocks of the Nuuk/Qeqertarsuatsiaat area comprise some of the oldest bedrock in Greenland which covers most of western Greenland. The surface has been altered several times and has an appearance as though it were shaped billions of years ago. This is one of the reasons why the Nuuk area is extraordinary and also because the particular climate zone for the area limits the vegetation which makes it possib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stable Isotope
The term stable isotope has a meaning similar to stable nuclide, but is preferably used when speaking of nuclides of a specific element. Hence, the plural form stable isotopes usually refers to isotopes of the same element. The relative abundance of such stable isotopes can be measured experimentally (isotope analysis), yielding an isotope ratio that can be used as a research tool. Theoretically, such stable isotopes could include the radiogenic daughter products of radioactive decay, used in radiometric dating. However, the expression stable-isotope ratio is preferably used to refer to isotopes whose relative abundances are affected by isotope fractionation in nature. This field is termed stable isotope geochemistry. Stable-isotope ratios Measurement of the ratios of naturally occurring stable isotopes (isotope analysis) plays an important role in isotope geochemistry, but stable isotopes (mostly hydrogen, carbon, nitrogen, oxygen and sulfur) are also finding uses in ecological ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-13
Carbon-13 (13C) is a natural, stable isotope of carbon with a nucleus containing six protons and seven neutrons. As one of the environmental isotopes, it makes up about 1.1% of all natural carbon on Earth. Detection by mass spectrometry A mass spectrum of an organic compound will usually contain a small peak of one mass unit greater than the apparent molecular ion peak (M) of the whole molecule. This is known as the M+1 peak and comes from the few molecules that contain a 13C atom in place of a 12C. A molecule containing one carbon atom will be expected to have an M+1 peak of approximately 1.1% of the size of the M peak, as 1.1% of the molecules will have a 13C rather than a 12C. Similarly, a molecule containing two carbon atoms will be expected to have an M+1 peak of approximately 2.2% of the size of the M peak, as there is double the previous likelihood that any molecule will contain a 13C atom. In the above, the mathematics and chemistry have been simplified, however it can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphite
Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large scale (300 kton/year, in 1989) for uses in pencils, lubricants, and electrodes. Under high pressures and temperatures it converts to diamond. It is a weak conductor of heat and electricity. Types and varieties Natural graphite The principal types of natural graphite, each occurring in different types of ore deposits, are * Crystalline small flakes of graphite (or flake graphite) occurs as isolated, flat, plate-like particles with hexagonal edges if unbroken. When broken the edges can be irregular or angular; * Amorphous graphite: very fine flake graphite is sometimes called amorphous; * Lump graphite (or vein graphite) occurs in fissure veins or fractures and appears as massive platy intergrowths of fibrous or acicular crystalline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with other atoms when it forms chemical compounds or molecules. Description The combining capacity, or affinity of an ...—its atom making four electrons available to form covalent bond, covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up only about 0.025 percent of Earth's crust. Three Isotopes of carbon, isotopes occur naturally, Carbon-12, C and Carbon-13, C being stable, while Carbon-14, C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the Timeline of chemical element discoveries#Ancient discoveries, few elements known since antiquity. Carbon is the 15th Abundance of elements in Earth's crust, most abundant element in the Earth's crust, and the Abundance of the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Circulation
Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie.'' Oxford: Clarendon Press. and θέρμη, ''heat'' ). Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earth's crust. In general, this occurs near volcanic activity, but can occur in the shallow to mid crust along deeply penetrating fault irregularities or in the deep crust related to the intrusion of granite, or as the result of orogeny or metamorphism. Seafloor hydrothermal circulation Hydrothermal circulation in the oceans is the passage of the water through mid-oceanic ridge systems. The term includes both the circulation of the well-known, high-temperature vent waters near the ridge crests, and the much-lower-temperature, diffuse flow of water through sedim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenland
Greenland ( kl, Kalaallit Nunaat, ; da, Grønland, ) is an island country in North America that is part of the Kingdom of Denmark. It is located between the Arctic and Atlantic oceans, east of the Canadian Arctic Archipelago. Greenland is the world's largest island. It is one of three constituent countries that form the Kingdom of Denmark, along with Denmark and the Faroe Islands; the citizens of these countries are all citizens of Denmark and the European Union. Greenland's capital is Nuuk. Though a part of the continent of North America, Greenland has been politically and culturally associated with Europe (specifically Norway and Denmark, the colonial powers) for more than a millennium, beginning in 986.The Fate of Greenland's Vikings , by Dale Mackenzie Brown, ''Archaeological Institute of America'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuuk
Nuuk (; da, Nuuk, formerly ) is the capital and largest city of Greenland, a constituent country of the Kingdom of Denmark. Nuuk is the seat of government and the country's largest cultural and economic centre. The major cities from other countries closest to the capital are Iqaluit and St. John's in Canada and Reykjavík in Iceland. Nuuk contains a third of Greenland's population and its tallest building. Nuuk is also the seat of government for the Sermersooq municipality. In January 2021, it had a population of 18,800. The city was founded in 1728 by the Dano-Norwegian missionary Hans Egede when he relocated from the earlier Hope Colony () where he arrived in 1721. The governor Claus Paarss was part of the relocation. The new colony was placed at the Inuit settlement of Nûk and was named ''Godthaab'' ("Good Hope"). "Nuuk" is the Greenlandic word for "cape" ( da, næs) and is commonly found in Greenlandic place names. It is so named because of its position at the end of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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