Effects of diffusion of water and migration of melts in crustal rocks: An experimental study

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F20%3A00000063" target="_blank" >RIV/00025798:_____/20:00000063 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/20:10424166

Výsledek na webu

<a href="https://doi.org/10.1016/j.chemgeo.2020.119548" target="_blank" >https://doi.org/10.1016/j.chemgeo.2020.119548</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemgeo.2020.119548" target="_blank" >10.1016/j.chemgeo.2020.119548</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effects of diffusion of water and migration of melts in crustal rocks: An experimental study

Popis výsledku v původním jazyce

Water and melts are crucial in controlling the chemistry, architecture, and dynamics of the Earth's crust.However, how water and melts influence chemical and textural changes of pervaded rocks during transport andhow they chemically react with surrounding minerals remain cryptic. We present experimental data illustratinghow water-undersaturated and potassium-rich melt in partially molten felsic granulite, or melt lost from suchgranulite affects the chemistry and texture of an initially, nearly anhydrous eclogite at high-pressure and hightemperature(1.2 GPa, 950 °C) for 20 h. The first experiment simulates interaction of eclogite with granulitehaving a small proportion of melt (melt = 2 volpercent, solids = 98 volpercent, with H2O = 0.4 wtpercent in the systemgranulite+melt, called in this paper granulite). The second experiment simulates interaction of eclogite withmelt (melt = 90 volpercent, solids = 10 volpercent, H2O = 4 wtpercent in the system granulite+melt, called in this papergranulite partial melt). Our results show that during granulite-eclogite interaction: i) the melt in the granulitecrystallises as a consequence of water diffusion into the eclogite; ii) this water causes partial replacement ofgarnet by plagioclase-orthopyroxene-magnetite-(±amphibole-) symplectite, whose volumetric proportioncorrelates with water content in the granulite; and iii) a small proportion of melt from the granulite (&#8804;2 volpercent)infiltrates into the eclogite, as documented by mineral overgrowths in granulite and by glass pools with increasedpotassium content in symplectites and along grain boundaries in the eclogite. Water and melt transferappears to be effective in causing textural changes, but appears to be ineffective in changing the bulk chemistryof the eclogite, even if local enrichment in potassium and water occurs. Such chemically stealthy diffusion ofwater and migration of limited amount of melt is able to cause major textural changes accompanied by localisedchemical changes at grain-scale that would not be otherwise observed at the scale of the bulk rock composition.

Název v anglickém jazyce

Effects of diffusion of water and migration of melts in crustal rocks: An experimental study

Popis výsledku anglicky

Water and melts are crucial in controlling the chemistry, architecture, and dynamics of the Earth's crust.However, how water and melts influence chemical and textural changes of pervaded rocks during transport andhow they chemically react with surrounding minerals remain cryptic. We present experimental data illustratinghow water-undersaturated and potassium-rich melt in partially molten felsic granulite, or melt lost from suchgranulite affects the chemistry and texture of an initially, nearly anhydrous eclogite at high-pressure and hightemperature(1.2 GPa, 950 °C) for 20 h. The first experiment simulates interaction of eclogite with granulitehaving a small proportion of melt (melt = 2 volpercent, solids = 98 volpercent, with H2O = 0.4 wtpercent in the systemgranulite+melt, called in this paper granulite). The second experiment simulates interaction of eclogite withmelt (melt = 90 volpercent, solids = 10 volpercent, H2O = 4 wtpercent in the system granulite+melt, called in this papergranulite partial melt). Our results show that during granulite-eclogite interaction: i) the melt in the granulitecrystallises as a consequence of water diffusion into the eclogite; ii) this water causes partial replacement ofgarnet by plagioclase-orthopyroxene-magnetite-(±amphibole-) symplectite, whose volumetric proportioncorrelates with water content in the granulite; and iii) a small proportion of melt from the granulite (&#8804;2 volpercent)infiltrates into the eclogite, as documented by mineral overgrowths in granulite and by glass pools with increasedpotassium content in symplectites and along grain boundaries in the eclogite. Water and melt transferappears to be effective in causing textural changes, but appears to be ineffective in changing the bulk chemistryof the eclogite, even if local enrichment in potassium and water occurs. Such chemically stealthy diffusion ofwater and migration of limited amount of melt is able to cause major textural changes accompanied by localisedchemical changes at grain-scale that would not be otherwise observed at the scale of the bulk rock composition.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA16-17457S" target="_blank" >GA16-17457S: Tavení metagranitoidů: důležitý avšak málo pochopený aspekt vývoje kontinentální kůry</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Chemical Geology

ISSN

0009-2541

e-ISSN

—

Svazek periodika

540

Číslo periodika v rámci svazku

May : 119548

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

15

Strana od-do

nestránkováno

Kód UT WoS článku

000525365400002

EID výsledku v databázi Scopus

2-s2.0-85080046555