Misplaced Pages

#105894

29-489: IVB may refer to: IVB meteorites , a group of iron meteorites Innsbrucker Verkehrsbetriebe , which runs the public transport system in Innsbruck The British Virgin Islands . Intel 3rd Generation Core Ivy Bridge (microarchitecture) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with

58-460: A 140   ±   30   km radius with a 70   ±   15   km radius core. The fast cooling rates are explained by a grazing-shot collision of the parent body with a larger asteroid. This removed the mantle from the parent body, leaving the shattered iron core behind to rapidly cool. As of December 2012, 14 specimens of IVB meteorites are known. A notable specimen is the Hoba meteorite ,

87-419: A chemical differentiate between the crust and the mantle, with occasional eruptions to the surface. Earth 's Moon probably formed out of material splashed into orbit by the impact of a large body into the early Earth. Differentiation on Earth had probably already separated many lighter materials toward the surface, so that the impact removed a disproportionate amount of silicate material from Earth, and left

116-500: A higher density. A light mineral such as plagioclase would rise. They may take on dome-shaped forms called diapirs when doing so. On Earth, salt domes are salt diapirs in the crust which rise through surrounding rock. Diapirs of molten low-density silicate rocks such as granite are abundant in the Earth's upper crust. The hydrated, low-density serpentinite formed by alteration of mantle material at subduction zones can also rise to

145-474: A metal to successfully travel through the fracture toughness of the surrounding material. The size of the metal intruding and the viscosity of the surrounding material determines the rate of the sinking process. The direct delivery of impacts occurs when an impactor of similar proportions strikes the target planetary body.  During the impact, there is an exchange of pre-existing cores containing metallic material. The planetary differentiation event

174-498: A timeline for accretion. Heating due to radioactivity, impacts, and gravitational pressure melted parts of protoplanets as they grew toward being planets . In melted zones, it was possible for denser materials to sink towards the center, while lighter materials rose to the surface. The compositions of some meteorites ( achondrites ) show that differentiation also took place in some asteroids (e.g. Vesta ), that are parental bodies for meteoroids. The short-lived radioactive isotope Al

203-565: Is low in volatile elements and high in nickel and refractory elements . Although most IVB meteorites are ataxites ("without structure"), they do show microscopic Widmanstätten patterns . The lamellae are smaller than 20   μm wide and lie in a matrix of plessite . The Tlacotepec meteorite is an octahedrite , making a notable exception, as most IVBs are ataxites . Iron meteorites were originally divided into four groups designated by Roman numerals (I, II, III, IV). When more chemical data became available some groups were split. Group IV

232-513: Is mediated by partial melting with heat from radioactive isotope decay and planetary accretion . Planetary differentiation has occurred on planets, dwarf planets , the asteroid 4 Vesta , and natural satellites (such as the Moon ). High- density materials tend to sink through lighter materials. This tendency is affected by the relative structural strengths, but such strength is reduced at temperatures where both materials are plastic or molten. Iron ,

261-502: Is said to have most likely happened after the accretion process of either the asteroid or a planetary body. Terrestrial bodies and iron meteorites consist of Fe-Ni alloys.  The Earth's core is primarily composed Fe-Ni alloys. Based on the studies of short lived radionuclides , the results suggest that core formation process occurred during an early stage of the solar system. Siderophile elements such as, sulfur , nickel , and cobalt can dissolve in molten iron; these elements help

290-400: Is thus depleted of those elements. Study of trace elements in igneous rocks thus gives us information about what source melted by how much to produce a magma, and which minerals have been lost from the melt. When material is unevenly heated, lighter material migrates toward hotter zones and heavier material migrates towards colder areas, which is known as thermophoresis , thermomigration, or

319-518: The Soret effect . This process can affect differentiation in magma chambers . A deeper understanding of this process can be drawn back to a study done on the Hawaiian lava lakes. The drilling of these lakes led to the discovery of crystals formed within magma fronts. The magma containing concentrations of these large crystals or phenocrysts demonstrated differentiation through the chemical melt of crystals. On

SECTION 10

#1733104321106

348-406: The Earth is produced by partial melting of a source rock, ultimately in the mantle . The melt extracts a large portion of the "incompatible elements" from its source that are not stable in the major minerals. When magma rises above a certain depth the dissolved minerals start to crystallize at particular pressures and temperatures. The resulting solids remove various elements from the melt, and melt

377-452: The IVB parent body has to take into account the extreme chemical composition, especially the depletion of volatile elements (gallium, germanium) and the enrichment in refractory elements (iridium) compared to other iron meteorites . The history of the parent body has been reconstructed in detail. The IVB parent body will have formed from material that condensed at the highest temperatures while

406-526: The Moon, a distinctive basaltic material has been found that is high in "incompatible elements" such as potassium , rare earth elements , and phosphorus and is often referred to by the abbreviation KREEP . It is also high in uranium and thorium . These elements are excluded from the major minerals of the lunar crust which crystallized out from its primeval magma ocean , and the KREEP basalt may have been trapped as

435-471: The Sun. Rocks, and the elements comprising them, were stripped of their early atmospheres, but themselves remained, to accumulate into protoplanets . Protoplanets had higher concentrations of radioactive elements early in their history, the quantity of which has reduced over time due to radioactive decay . For example, the hafnium-tungsten system demonstrates the decay of two unstable isotopes and possibly forms

464-401: The differentiation of iron alloys. The first stages of accretion set up the groundwork for core formation. First, terrestrial planetary bodies enter a neighboring planet's orbit. Next, a collision would take place and the terrestrial body could either grow or shrink. However, in most cases, accretion requires multiple collisions of similar sized objects to have a major difference in

493-418: The largest known intact meteorite. There has never been an observed fall of an IVB meteorite. Planetary differentiation In planetary science , planetary differentiation is the process by which the chemical elements of a planetary body accumulate in different areas of that body, due to their physical or chemical behavior (e.g. density and chemical affinities). The process of planetary differentiation

522-468: The majority of the dense metal behind. The Moon's density is substantially less than that of Earth, due to its lack of a large iron core. On Earth , physical and chemical differentiation processes led to a crustal density of approximately 2700 kg/m compared to the 3400 kg/m density of the compositionally different mantle just below, and the average density of the planet as a whole is 5515 kg/m . Core formation utilizes several mechanisms in order to control

551-401: The most common element that is likely to form a very dense molten metal phase, tends to congregate towards planetary interiors. With it, many siderophile elements (i.e. materials that readily alloy with iron) also travel downward. However, not all heavy elements make this transition as some chalcophilic heavy elements bind into low-density silicate and oxide compounds, which differentiate in

580-531: The movement of metals into the interior of a planetary body. Examples include percolation , diking , diapirism, and the direct delivery of impacts are mechanisms involved in this process. The metal to silicate density difference causes percolation or the movement of a metal downward. Diking is a process in which a new rock formation forms within a fracture of a pre-existing rock body. For example, if minerals are cold and brittle, transport can occur through fluid cracks. A sufficient amount of pressure must be met for

609-462: The opposite direction. The main compositionally differentiated zones in the solid Earth are the very dense iron-rich metallic core , the less dense magnesium-silicate -rich mantle and the relatively thin, light crust composed mainly of silicates of aluminium , sodium , calcium and potassium . Even lighter still are the watery liquid hydrosphere and the gaseous, nitrogen-rich atmosphere . Lighter materials tend to rise through material with

SECTION 20

#1733104321106

638-454: The planet body into a core and mantle was most likely driven by the heat produced by the decay of Al and Fe . The high nickel concentrations were caused by oxidizing physical conditions. The chemical variation of IVB specimens can be explained as different stages of the fractional crystallization of the convecting core of the parent body. The exact size of the parent body is still debated. Modelling of cooling rates suggest that it had

667-462: The rare element uranium is very dense as a pure element, it is chemically more compatible as a trace element in the Earth's light, silicate -rich crust than in the dense metallic core. When the Sun ignited in the solar nebula , hydrogen , helium and other volatile materials were evaporated in the region around it. The solar wind and radiation pressure forced these low-density materials away from

696-402: The solar nebula cooled off. The enrichment in refractory elements was caused by less than 10   % of the condensible material going into the parent body. Thermal models suggest that the IVB parent body formed 0.3   million   years after the formation of the calcium-aluminium-rich inclusions , and at a distance from the sun of 0.9   Astronomical units . Differentiation of

725-409: The surface as diapirs. Other materials do likewise: a low-temperature, near-surface example is provided by mud volcanoes . Although bulk materials differentiate outward or inward according to their density, the elements that are chemically bound in them fractionate according to their chemical affinities, "carried along" by more abundant materials with which they are associated. For instance, although

754-427: The surface. Another external heat source is tidal heating . On Earth , a large piece of molten iron is sufficiently denser than continental crust material to force its way down through the crust to the mantle . In the outer Solar System, a similar process may take place but with lighter materials: they may be hydrocarbons such as methane , water as liquid or ice, or frozen carbon dioxide . Magma in

783-559: The title IVB . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=IVB&oldid=1089205328 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages IVB meteorites The IVB meteorites are composed of meteoric iron ( kamacite , taenite and tetrataenite ). The chemical composition

812-435: Was probably the main source of heat. When protoplanets accrete more material, the energy of impact causes local heating. In addition to this temporary heating, the gravitational force in a sufficiently large body creates pressures and temperatures which are sufficient to melt some of the materials. This allows chemical reactions and density differences to mix and separate materials, and soft materials to spread out over

841-404: Was split into IVA and IVB meteorites. The chemical classification is based on diagrams that plot nickel content against different trace elements (e.g. gallium , germanium and iridium ). The different iron meteorite groups appear as data point clusters. IVB meteorites formed the core of a parent body that was later destroyed, some of the fragments falling on Earth as meteorites. Modeling

#105894