Exhumation of subducted continental crust along the arc region

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F20%3A00000032" target="_blank" >RIV/00025798:_____/20:00000032 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985530:_____/20:00524938

Výsledek na webu

<a href="https://doi.org/10.1016/j.gr.2019.10.011" target="_blank" >https://doi.org/10.1016/j.gr.2019.10.011</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.gr.2019.10.011" target="_blank" >10.1016/j.gr.2019.10.011</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Exhumation of subducted continental crust along the arc region

Popis výsledku v původním jazyce

The Kutná Hora crystalline complex (KHCC) in the Bohemian Massif is a partially molten HP/HT complex adjacent to the magmatic arc. It is dominated by migmatite, orthogneiss and granulite with bodies of eclogite and peridotite. The KHCC migmatite consists of K-feldspar, plagioclase, quartz, phengite, biotite, garnet and kyanite. Melting conditions were estimated at 780 °C and >16 kbar and inferred melt volume varies between 1 to 4 vol percent. Peak temperature is 865 °C at 18–19 kbar followed by decompression in the presence of melt to 12–13 kbar and 770–800 °C. U-Pb monazite geochronology reveals a spread of ages between 550 Ma and 330 Ma. REE patterns show low Yb/Gd for 550&#8722;500 Ma, high Yb/Gd for ages at ~ 480 Ma, and decreasing Yb/Gd towards ~340 Ma. First monazite in equilibrium with garnet constrains the HP metamorphism to ~ 350 Ma, which is followed by recrystallization of monazite down to 325 Ma. U-Pb zircon geochronology displays an age range from ~ 670 Ma to ~ 430 Ma. The broad age range records a span of protolith crystallization and/or old metamorphism. The presence of HP ky+mu migmatite, their P–T path, protolith zircon and monazite metamorphic ages and whole-rock geochemistry are similar to HP migmatites in the Eger crystalline complex (ECC) in the Saxothuringian domain further in the west. We propose the following geodynamic scenario for subduction-relamination-exhumation mechanism: (i) subduction of the Saxothuringian continental lithosphere at 360 Ma related to early stage of trans-lithospheric diapirism triggered by arc-related magma weakening; (ii) large-scale emplacement of relaminant into the upper plate lithosphere at 350–340 Ma; and (iii) return flow of the relaminant along the subduction interface (the ECC) and emplacement of relaminant in the upper–middle crust in the rear part of the arc system (the KHCC) at 340–330 Ma.

Název v anglickém jazyce

Exhumation of subducted continental crust along the arc region

Popis výsledku anglicky

The Kutná Hora crystalline complex (KHCC) in the Bohemian Massif is a partially molten HP/HT complex adjacent to the magmatic arc. It is dominated by migmatite, orthogneiss and granulite with bodies of eclogite and peridotite. The KHCC migmatite consists of K-feldspar, plagioclase, quartz, phengite, biotite, garnet and kyanite. Melting conditions were estimated at 780 °C and >16 kbar and inferred melt volume varies between 1 to 4 vol percent. Peak temperature is 865 °C at 18–19 kbar followed by decompression in the presence of melt to 12–13 kbar and 770–800 °C. U-Pb monazite geochronology reveals a spread of ages between 550 Ma and 330 Ma. REE patterns show low Yb/Gd for 550&#8722;500 Ma, high Yb/Gd for ages at ~ 480 Ma, and decreasing Yb/Gd towards ~340 Ma. First monazite in equilibrium with garnet constrains the HP metamorphism to ~ 350 Ma, which is followed by recrystallization of monazite down to 325 Ma. U-Pb zircon geochronology displays an age range from ~ 670 Ma to ~ 430 Ma. The broad age range records a span of protolith crystallization and/or old metamorphism. The presence of HP ky+mu migmatite, their P–T path, protolith zircon and monazite metamorphic ages and whole-rock geochemistry are similar to HP migmatites in the Eger crystalline complex (ECC) in the Saxothuringian domain further in the west. We propose the following geodynamic scenario for subduction-relamination-exhumation mechanism: (i) subduction of the Saxothuringian continental lithosphere at 360 Ma related to early stage of trans-lithospheric diapirism triggered by arc-related magma weakening; (ii) large-scale emplacement of relaminant into the upper plate lithosphere at 350–340 Ma; and (iii) return flow of the relaminant along the subduction interface (the ECC) and emplacement of relaminant in the upper–middle crust in the rear part of the arc system (the KHCC) at 340–330 Ma.

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

Gondwana research

ISSN

1342-937X

e-ISSN

—

Svazek periodika

80

Číslo periodika v rámci svazku

April

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

30

Strana od-do

157-187

Kód UT WoS článku

000522974700007

EID výsledku v databázi Scopus

2-s2.0-85076032041