Felsic granulite with layers of eclogite facies rocks in the Bohemian Massif; did they share a common metamorphic history?

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F17%3A10363709" target="_blank" >RIV/00216208:11310/17:10363709 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.lithos.2017.06.027" target="_blank" >http://dx.doi.org/10.1016/j.lithos.2017.06.027</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.lithos.2017.06.027" target="_blank" >10.1016/j.lithos.2017.06.027</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Felsic granulite with layers of eclogite facies rocks in the Bohemian Massif; did they share a common metamorphic history?

Popis výsledku v původním jazyce

High pressure granulite from the Rychleby Mountains in the East Sudetes is enclosed by amphibolite facies orthogneiss with a steep foliation. Well preserved felsic granulite is located in the central part of the body, where several small bodies of mafic granulite are also present. In comparison to other high pressure granulites in the Bohemian Massif, which show strong mineral and textural re-equilibration under granulite facies conditions, the mafic granulite samples preserve eclogite facies minerals and their field and textural relations indicate that both mafic and felsic granulites shared common metamorphic history during prograde eclogite facies and subsequent granulite facies events. Garnet from both granulite varieties shows prograde compositional zoning and contains inclusions of phengite. Y+REEs in garnet show typical bell-shaped distributions with no annular peaks near the grain rims. Investigation of major and trace elements zoning, including REEs distribution in garnet, was combined with thermodynamic modelling to constrain the early eclogite facies metamorphism and to estimate pressure-temperature conditions of the subsequent granulite facies overprint. The first (U)HP metamorphism occurred along a low geothermal gradient in a subduction-related environment from its initial stage at 0.8 GPa/460 °C and reached pressures up to 2.5 GPa at 550 °C. The subsequent granulite facies overprint (1.6-1.8 GPa/800-880 °C) affected the rocks only partially; by replacement of omphacite into diopside+plagioclase symplectite and by compositional modification of garnet rims. The mineral textures and the preservation of the eclogite facies prograde compositional zoning in garnet cores confirm that the granulite facies overprint was either too short or too faint to cause recrystallisation and homogenisation of the eclogite facies mineral assemblage. The results of this study are compared with other granulite massifs in the Moldanubian Zone.

Název v anglickém jazyce

Felsic granulite with layers of eclogite facies rocks in the Bohemian Massif; did they share a common metamorphic history?

Popis výsledku anglicky

High pressure granulite from the Rychleby Mountains in the East Sudetes is enclosed by amphibolite facies orthogneiss with a steep foliation. Well preserved felsic granulite is located in the central part of the body, where several small bodies of mafic granulite are also present. In comparison to other high pressure granulites in the Bohemian Massif, which show strong mineral and textural re-equilibration under granulite facies conditions, the mafic granulite samples preserve eclogite facies minerals and their field and textural relations indicate that both mafic and felsic granulites shared common metamorphic history during prograde eclogite facies and subsequent granulite facies events. Garnet from both granulite varieties shows prograde compositional zoning and contains inclusions of phengite. Y+REEs in garnet show typical bell-shaped distributions with no annular peaks near the grain rims. Investigation of major and trace elements zoning, including REEs distribution in garnet, was combined with thermodynamic modelling to constrain the early eclogite facies metamorphism and to estimate pressure-temperature conditions of the subsequent granulite facies overprint. The first (U)HP metamorphism occurred along a low geothermal gradient in a subduction-related environment from its initial stage at 0.8 GPa/460 °C and reached pressures up to 2.5 GPa at 550 °C. The subsequent granulite facies overprint (1.6-1.8 GPa/800-880 °C) affected the rocks only partially; by replacement of omphacite into diopside+plagioclase symplectite and by compositional modification of garnet rims. The mineral textures and the preservation of the eclogite facies prograde compositional zoning in garnet cores confirm that the granulite facies overprint was either too short or too faint to cause recrystallisation and homogenisation of the eclogite facies mineral assemblage. The results of this study are compared with other granulite massifs in the Moldanubian Zone.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA13-06958S" target="_blank" >GA13-06958S: Záznam minerálních a texturních znaků před exhumačního a před kolizního vývoje HP/UHP hornin v orogenní zóně</a><br>

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Lithos

ISSN

0024-4937

e-ISSN

—

Svazek periodika

286-287

Číslo periodika v rámci svazku

August 2017

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

18

Strana od-do

408-425

Kód UT WoS článku

000408286700027

EID výsledku v databázi Scopus

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