Syn-deformational melt percolation through a high-pressure orthogneiss and the exhumation of a subducted continental wedge

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F20%3A00524936" target="_blank" >RIV/67985530:_____/20:00524936 - 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

Popis výsledku v původním jazyce

High-pressure granitic orthogneiss of the south-eastern Orlica-snie(z) over dotnik 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 similar to 15-16 kbar and similar to 650-740 oC to similar to 6 kbar and similar to 640 oC. 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 similar to 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

Popis výsledku anglicky

High-pressure granitic orthogneiss of the south-eastern Orlica-snie(z) over dotnik 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 similar to 15-16 kbar and similar to 650-740 oC to similar to 6 kbar and similar to 640 oC. 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 similar to 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

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

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

34

Strana od-do

1213-1246

Kód UT WoS článku

000520663800001

EID výsledku v databázi Scopus

2-s2.0-85082771928