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 (mĕt′ə-sō′mə-tĭz′əm) also met·a·so·ma·to·sis (-sō′mə-tō′sĭs)
The process by which the chemical composition of a rock is changed by interaction with fluids; replacement of one mineral by another without melting.

met′a·so·mat′ic (-măt′ĭk) adj.
met′a·so·mat′i·cal·ly adv.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(ˌmɛtəˈsəʊməˌtɪzəm) or


(Geological Science) change in the composition of a rock or mineral by the addition or replacement of chemicals
[C19: from New Latin; see meta-, somato-]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˌmɛt əˈsoʊ məˌtɪz əm)

also met•a•so•ma•to•sis

(-ˌsoʊ məˈtoʊ sɪs)

the series of metamorphic processes whereby chemical changes occur in minerals or rocks as a result of the introduction of material, often in hot aqueous solutions, from external sources.
met`a•so•mat′ic (-ˈmæt ɪk) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


the process of chemical change in rocks or other mineral masses that results in the formation of new rocks or minerals. Also metasomatosis.
See also: Geology
-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.
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References in periodicals archive ?
It is produced by dynamo thermal metamorphism and metasomatism, which occur in the zones where tectonic plates are subducted, changing rocks by heat and pressure, with influx of fluids but without melting.
Gresens, R.L.: 1967, Composition-volume relationships of metasomatism. Chemical Geology, 2, 47-55.
In many geological processes, Y/Ho, Zr/Hf, and Nb/Ta ratios are stable in one hydrothermal system; however, when the system is disturbed by hydrothermal activities or metasomatism, these element pairs will change significantly, and are presented as a large variation range among different samples (Bau et al., 1995; Yaxley et al., 1998).
It was corroborated by the study of Pirajno [25] who found that the hydrothermal alteration might generate argillic and result in the formation of clay minerals because of the increase in [H.sup.+] activities during the alteration sequence of the metasomatism process in which the mineral exchange occurred between the altered rocks and the ions carried by water [26].
Since crystals record changes occurring in the environment in which they grow (e.g., [7,11-15]), isotopic investigations at grain and subgrain scales on rock-forming minerals provide information on mineral-whole rock equilibria that constrain the magmatic processes occurring during magma evolution (e.g., mixing, mingling, crystals recycling, crustal contamination, or metasomatism).
The whole rock geochemistry records fluid mobilization and chemical transport, which supports a close relationship between metasomatism and mineral deposition.
The rocks of Gabal El-Rubshi are highly susceptible to alteration into talc carbonate rocks as a result of CO2 metasomatism [6].
( The study , published in the latest edition of the journal Earth and Planetary Science Letters, calls this mechanism of deposition of silicate minerals "aerial metasomatism."
The mineral compositions included boulder clay, single-crystal quartz, metaquartzite, and flint, among which metaquartzite and flint were the primary components; calcium metasomatism was part of the metaquartzite.
Tang, "Iron isotope variations in spinel peridotite xenoliths from North China Craton: Implications for mantle metasomatism," Contributions to Mineralogy and Petrology, vol.
Unraveling the effects of potassium metasomatism in sedimentary rocks and paleosols, with implications for paleo weathering conditions and provenance.