Syn‑deformational melt percolation through a high‑pressure orthogneiss and the exhumation of a subducted continental wedge (Orlica‑Śnieżnik Dome, NE Bohemian Massif)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F20%3A00000085" target="_blank" >RIV/00025798:_____/20:00000085 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/article/10.1007/s00531-020-01838-4" target="_blank" >https://link.springer.com/article/10.1007/s00531-020-01838-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00531-020-01838-4" target="_blank" >10.1007/s00531-020-01838-4</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Syn‑deformational melt percolation through a high‑pressure orthogneiss and the exhumation of a subducted continental wedge (Orlica‑Śnieżnik Dome, NE Bohemian Massif)

Popis výsledku v původním jazyce

High-pressure granitic orthogneiss of the south-eastern Orlica–Śnieżnik Dome (NE Bohemian Massif) shows relics of a shallow-dipping foliation, reworked by upright folds and a mostly pervasive N–S trending subvertical axial planar foliation. Based on macroscopic observations, a gradual transition from banded to schlieren and nebulitic orthogneiss was distinguished. All rock types comprise plagioclase, K-feldspar, quartz, white mica, biotite and garnet. The transition is characterized by increasing presence of interstitial phases along like-like grain boundaries and by progressive replacement of recrystallized K-feldspar grains by fine-grained myrmekite. These textural changes are characteristic for syn-deformational grain-scale melt percolation, which is in line with the observed enrichment of the rocks in incompatible elements such as REEs, Ba, Sr and K suggesting open-system behaviour with melt passing through the rocks. The P–T path deduced from the thermodynamic modelling indicates decompression from ~ 15&#8722;16 kbar and ~ 650–740 &#186;C to ~ 6 kbar and ~ 640 &#186;C. Melt was already present at the P–T peak conditions as indicated by the albitic composition of plagioclase in films, interstitial grains and in myrmekite. The variably re-equilibrated garnet suggests that melt content may have varied along the decompression path, involving successively both melt gain and loss. The ~ 6–8 km wide zone of vertical foliation and migmatite textural gradients is interpreted as vertical crustal-scale channel where the grain-scale melt percolation was associated with horizontal shortening and vertical flow of partially molten crustal wedge en masse.

Název v anglickém jazyce

Syn‑deformational melt percolation through a high‑pressure orthogneiss and the exhumation of a subducted continental wedge (Orlica‑Śnieżnik Dome, NE Bohemian Massif)

Popis výsledku anglicky

High-pressure granitic orthogneiss of the south-eastern Orlica–Śnieżnik Dome (NE Bohemian Massif) shows relics of a shallow-dipping foliation, reworked by upright folds and a mostly pervasive N–S trending subvertical axial planar foliation. Based on macroscopic observations, a gradual transition from banded to schlieren and nebulitic orthogneiss was distinguished. All rock types comprise plagioclase, K-feldspar, quartz, white mica, biotite and garnet. The transition is characterized by increasing presence of interstitial phases along like-like grain boundaries and by progressive replacement of recrystallized K-feldspar grains by fine-grained myrmekite. These textural changes are characteristic for syn-deformational grain-scale melt percolation, which is in line with the observed enrichment of the rocks in incompatible elements such as REEs, Ba, Sr and K suggesting open-system behaviour with melt passing through the rocks. The P–T path deduced from the thermodynamic modelling indicates decompression from ~ 15&#8722;16 kbar and ~ 650–740 &#186;C to ~ 6 kbar and ~ 640 &#186;C. Melt was already present at the P–T peak conditions as indicated by the albitic composition of plagioclase in films, interstitial grains and in myrmekite. The variably re-equilibrated garnet suggests that melt content may have varied along the decompression path, involving successively both melt gain and loss. The ~ 6–8 km wide zone of vertical foliation and migmatite textural gradients is interpreted as vertical crustal-scale channel where the grain-scale melt percolation was associated with horizontal shortening and vertical flow of partially molten crustal wedge en masse.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA19-25035S" target="_blank" >GA19-25035S: Granulito–migmatitové dómy - náhled do devonského a karbonského vývoje Variského orogenního pásma</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

International Journal of Earth Sciences

ISSN

1437-3254

e-ISSN

—

Svazek periodika

109

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

33

Strana od-do

1213-1246

Kód UT WoS článku

000520663800001

EID výsledku v databázi Scopus

2-s2.0-85082771928