| 词汇 | magma |
| 释义 | magma noun[ U ] uk /ˈmæɡ.mə/ us /ˈmæɡ.mə/ hot liquid rock found just below the surface of the earth岩浆 Geology: types of rock agglomerate arenaceous arenite asthenosphere asthenospheric emery flinty gneiss haematite indurated intrusive lahar limestone lodestone marl marmoreal obsidian sandstone schist shale You can also find related words, phrases, and synonyms in the topics: Geology: earthquakes & volcanic eruptions Sometimes, the magma below a volcano becomes even hotter and moves towards the top. Suddenly, the top of the volcano breaks open, and thousands of kilograms of boiling magma and ash fly up into the air. This is so hot that the rock is not hard, it is a boiling liquid called magma. Volcanoes are mountains that have a lot of magma below them. magma | American Dictionarymagma noun[ U ] us/ˈmæɡ·mə/ earth science melted rock under the surface of the earth Examples of magmamagma This characteristic also inhibits development of pronounced vertical zonation of the magma body. Crustally-contaminated andesites could be produced by combined assimilation and fractional crystallization of basaltic magmas. Second, differentiation, mixing, assimilation of magmas and alteration can produce compositional trends that can cross field boundaries within discrimination diagrams. These constituents are formed rapidly from cooled droplets of magma that take on dynamic shape during transport. Even if such a magma chamber extended through the entire crust, its height/diameter ratio would still be less than one. It is therefore likely that generation of the widespread intermediate-silicic magmas represents an early stage in the formation of continental crust. Constraints on melting and magma production in the crust. The rise of felsic magma to a high level in the crust without degassing or neutralization of the melt volatile phase suggests deep faulting. In particular, the heat for the melting may have been supplied by mafic mantle-derived magmas. The role of mantle plumes, particularly in the generation of flood basaltic magmas, has been emphasized by many authors. With all these processes, interactions between mantle-derived and crustal-derived magmas control the nature of magmatism in the complex. However, the geochemical data are consistent with derivation of magmas from a mantle source modified by subduction processes. The mafic magmas were probably derived from the upper mantle (spinel stability field) by 9 % partial melting. The magmas are of transitional (mildly alkalic) type, generated by relatively small-fraction (6-7 %) melting of a depleted mantle source. The evidence, including that of xenoliths carried in the magmas, supports the idea of melting of old metasomatized lithospheric mantle, usually associated with rifting tectonics. These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. Collocations withmagmamagmaThese are words often used in combination with magma. Click on a collocation to see more examples of it. basaltic magma The fluid dynamics of a basaltic magma chamber replenished by influx of hot, dense, ultrabasic magma. hot magma Under the mountains, there is a very large, very hotmagma chamber which leads to the originating of glacier caves. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license. magma chamber Instead, it promotes quasi-equilibrium crystallization in small domains within a large heterogeneous magmachamber. These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. See all collocations with magma |
| 随便看 |
|
反思网英语在线翻译词典收录了377474条英语词汇在线翻译词条，基本涵盖了全部常用英语词汇的中英文双语翻译及用法，是英语学习的有利工具。