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Lutetium–hafnium Dating
Lutetium–hafnium dating is a Geochronology, geochronological dating method utilizing the radioactive decay system of lutetium–176 to hafnium–176. With a commonly accepted half-life of 37.1 billion years, the long-living Lu–Hf decay pair survives through geological time scales, thus is useful in geological studies. Due to chemical properties of the two elements, namely their Valence (chemistry), valences and Ionic radius, ionic radii, Lu is usually found in trace amount in rare-earth element loving minerals, such as garnet and Phosphate minerals, phosphates, while Hf is usually found in trace amount in zirconium-rich minerals, such as zircon, baddeleyite and zirkelite. The trace concentration of the Lu and Hf in earth materials posed some technological difficulties in using Lu–Hf dating extensively in the 1980s. With the use of inductively coupled plasma mass spectrometry (ICP–MS) with multi-collector (also known as MC–ICP–MS) in later years, the dating method is mad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture. They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractory (planetary Science)
In planetary science, any material that has a relatively high equilibrium condensation temperature is called refractory. The opposite of refractory is volatile. The refractory group includes elements and compounds like metals and silicates (commonly termed rocks) which make up the bulk of the mass of the terrestrial planets and asteroids in the inner belt. A fraction of the mass of other asteroids An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ..., giant planets, their moons and trans-Neptunian objects is also made of refractory materials. Classification The elements can be divided into several categories: The condensation temperatures are the temperatures at which 50% of the element will be in the form of a solid (rock) under a pressure of 10−4 bar. However, slightly dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Evolution
Planetary means relating to a planet or planets. It can also refer to: Science * Planetary habitability, the measure of an astronomical body's potential to develop and sustain life * Planetary nebula, an astronomical object People * Planetary (rapper), one half of east coast rap group OuterSpace Arts, entertainment, and media * ''Planetary'' (comics), a comic book series by Warren Ellis and John Cassaday * "Planetary (Go!)", a 2011 song by rock band My Chemical Romance * ''Planetary Radio'', a public radio show about space exploration, produced by The Planetary Society Organizations * The Planetary Society, the Earth's largest space interest group Technology * Epicyclic gearing An epicyclic gear train (also known as a planetary gearset) is a gear reduction assembly consisting of two gears mounted so that the center of one gear (the "planet") revolves around the center of the other (the "sun"). A carrier connects the ... (planetary gearing), an automotive transmission te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondritic Uniform Reservoir
The Chondritic Uniform Reservoir (CHUR) is a scientific model in astrophysics and geochemistry for the mean chemical composition of the part of the Solar Nebula from which, during the formation of the Solar System, chondrites formed. This hypothetical chemical reservoir is thought to have been similar in composition to the current photosphere of the Sun. When the Sun formed from its protostar, around 4.56 billion years ago, the solar wind caused outward dispersal of gas particles from the central part of the Solar Nebula. In this way, most lighter volatiles (e.g. hydrogen, helium, oxygen, carbon dioxide), that had not yet condensed in the inner, warmer regions of the nebula, were lost. This fractionation process caused the terrestrial planets and asteroid belt to become relatively enriched in heavy elements, with respect to the composition of the Sun and the Jovian gas planets. Certain type of meteorites, CI-chondrites, have chemical compositions that are almost identical to the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isochron Dating
Isochron dating is a common technique of radiometric dating and is applied to date certain events, such as crystallization, metamorphism, shock events, and differentiation of precursor melts, in the history of rocks. Isochron dating can be further separated into ''mineral isochron dating'' and ''whole rock isochron dating''; both techniques are applied frequently to date terrestrial and extraterrestrial rocks (meteorites and Moon rocks). The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter nuclide in the radioactive decay sequence. Indeed, the initial amount of the daughter product can be determined using isochron dating. This technique can be applied if the daughter element has at least one stable isotope other than the daughter isotope into which the parent nuclide decays. Basis for method All forms of isochron dating assume that the source of the rock or rocks contained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mass Spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures. A mass spectrum is a type of plot of the ion signal as a function of the mass-to-charge ratio. These spectra are used to determine the elemental or isotopic signature of a sample, the masses of particles and of molecules, and to elucidate the chemical identity or structure of molecules and other chemical compounds. In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionization, ionized, for example by bombarding it with a Electron ionization, beam of electrons. This may cause some of the sample's molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figure 2 High Res Debaille Et Al (2017) The Role Of Phosphates For The Lu–Hf Chronology Of Meteorites
Figure may refer to: General *A shape, drawing, depiction, or geometric configuration *Figure (wood), wood appearance *Figure (music), distinguished from musical motif *Noise figure, in telecommunication *Dance figure, an elementary dance pattern *A person's figure, human physical appearance *Figure–ground (perception), the distinction between a visually perceived object and its surroundings Arts *Figurine, a miniature statuette representation of a creature *Action figure, a posable jointed solid plastic character figurine *Figure painting, realistic representation, especially of the human form *Figure drawing *Model figure, a scale model of a creature Writing *figure, in writing, a type of floating block (text, table, or graphic separate from the main text) *Figure of speech, also called a rhetorical figure *Christ figure, a type of character * in typesetting, text figures and lining figures Accounting *Figure, a synonym for number *Significant figures in a decimal number ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ytterbium
Ytterbium is a chemical element; it has symbol Yb and atomic number 70. It is a metal, the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state. Like the other lanthanides, its most common oxidation state is +3, as in its oxide, halides, and other compounds. In aqueous solution, like compounds of other late lanthanides, soluble ytterbium compounds form complexes with nine water molecules. Because of its closed-shell electron configuration, its density, melting point and boiling point are much lower than those of most other lanthanides. In 1878, Swiss chemist Jean Charles Galissard de Marignac separated from the rare earth "erbia", another independent component, which he called " ytterbia", for Ytterby, the village in Sweden near where he found the new component of erbium. He suspected that ytterbia was a compound of a new element that he called "ytterbium". Four elements were named after the village, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
