“chondrite”的概念、定义、翻译、参考文献-科学参考

chondrite

Astronomy

A type of stony meteorite, so named because most (though not all) contain small spherules termed chondrules. Chondrites are the most abundant class of meteorite, accounting for around 82% of all falls. They are largely composed of iron- and magnesium-bearing silicate minerals. Except for the most volatile elements, their chemical composition closely resembles that of the Sun, and presumably the solar nebula. Chondrites are divided into three main classes primarily on the basis of their chemistry. Enstatite or E-chondrites contain the most refractory elements and are highly reduced. Carbonaceous or C-chondrites contain about 3% carbon; these have the highest proportions of volatile substances, and are the most oxidized. Ordinary chondrites, the most common type, are intermediate in their abundance of volatile elements and oxidation state. Each of the three main classes of chondrite is divided into several subgroups on the basis of composition, and each subgroup may be further subdivided into several types on the basis of their texture and mineralogy.

Space Exploration

A type of meteorite characterized by chondrules (small spherules), typically about 1 mm in diameter, made up of silicate material.

Geology and Earth Sciences

Stony meteorite; the majority of chondrites are characterized by the presence of chondrules, and they constitute about 86% of meteorite falls. The principal minerals they contain are olivine, pyroxene, plagioclase feldspar, troilite, and the iron-nickel minerals kamacite and taenite. Chondrites are grouped according to their petrological type (texture, crystal structure, etc.) into six classes. On the basis of their chemical composition they fall into five main groups: enstatite chondrites (highly reduced, iron in metallic form); high-Fe (H) chondrites; low-Fe (L) chondrites; low-Fe/low-metal (LL) chondrites (some iron in silicate form); and carbonaceous chondrites (relatively high oxidation levels, containing volatiles). C1 chondrites are often used as a chemical model for the bulk composition of the Earth, but there are notable discrepancies, e.g. in the proportions of volatile elements.

单词	chondrite
释义	chondrite Astronomy A type of stony meteorite, so named because most (though not all) contain small spherules termed chondrules. Chondrites are the most abundant class of meteorite, accounting for around 82% of all falls. They are largely composed of iron- and magnesium-bearing silicate minerals. Except for the most volatile elements, their chemical composition closely resembles that of the Sun, and presumably the solar nebula. Chondrites are divided into three main classes primarily on the basis of their chemistry. Enstatite or E-chondrites contain the most refractory elements and are highly reduced. Carbonaceous or C-chondrites contain about 3% carbon; these have the highest proportions of volatile substances, and are the most oxidized. Ordinary chondrites, the most common type, are intermediate in their abundance of volatile elements and oxidation state. Each of the three main classes of chondrite is divided into several subgroups on the basis of composition, and each subgroup may be further subdivided into several types on the basis of their texture and mineralogy. Space Exploration A type of meteorite characterized by chondrules (small spherules), typically about 1 mm in diameter, made up of silicate material. Geology and Earth Sciences Stony meteorite; the majority of chondrites are characterized by the presence of chondrules, and they constitute about 86% of meteorite falls. The principal minerals they contain are olivine, pyroxene, plagioclase feldspar, troilite, and the iron-nickel minerals kamacite and taenite. Chondrites are grouped according to their petrological type (texture, crystal structure, etc.) into six classes. On the basis of their chemical composition they fall into five main groups: enstatite chondrites (highly reduced, iron in metallic form); high-Fe (H) chondrites; low-Fe (L) chondrites; low-Fe/low-metal (LL) chondrites (some iron in silicate form); and carbonaceous chondrites (relatively high oxidation levels, containing volatiles). C1 chondrites are often used as a chemical model for the bulk composition of the Earth, but there are notable discrepancies, e.g. in the proportions of volatile elements.
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