Devonian subduction retreat recorded in the Chinese Altai Orogen: Petro-structural and geochronological constraints from orogenic lower crust migmatite-granite complexes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F23%3A10168704" target="_blank" >RIV/00025798:_____/23:10168704 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.jseaes.2023.105540" target="_blank" >https://doi.org/10.1016/j.jseaes.2023.105540</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jseaes.2023.105540" target="_blank" >10.1016/j.jseaes.2023.105540</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Devonian subduction retreat recorded in the Chinese Altai Orogen: Petro-structural and geochronological constraints from orogenic lower crust migmatite-granite complexes

Popis výsledku v původním jazyce

Crustal extension due to the retreat of subduction system has been assigned as an important mechanism gov-erning the Devonian tectonic evolution of the Chinese Altai Orogen in central Asia. While the extensional regime has been repeatedly inferred from petro-structural (petrographic and structural) records preserved in the orogenic upper crust sedimentary covers and orogenic middle crust schists, such records have rarely been documented in the deep crustal migmatitic and/or magmatic rocks. This gap is filled in this study by applying combined petro-structural analysis in conjunction with zircon and monazite U-Pb geochronology on represen-tative orogenic lower crustal migmatite-granite complexes. These complexes are characterized by the develop-ment of a sub-horizontal foliation associated with extensional melt-filled shear bands. The foliation commonly contains garnet-sillimanite +/- K-feldspar +/- cordierite-bearing metamorphic assemblages that are compatible with a low-pressure/high-temperature thermal regime. In addition, such mineral assemblages are usually found to replace pre-existing middle-pressure/middle-temperature Barrovian-type ones, reflecting a tectonic switch from thickening to extension. New monazite and zircon U-Pb age data, together with regional pre-existing ages, suggest that the sub-horizontal high-temperature foliation formed during a period of 420-390 Ma. Combined with previously published data, our data reinforce that a crustal-scale extensional tectonic regime developed in response to retreating of subduction system governed the geodynamic evolution of the Chinese Altai Orogen during Devonian times. This process led to regional anatexis of the pre-existing Ordovician accretionary wedge complex, facilitated the formation of stabilized and vertically stratified continental crust, and promoted the metallogenic evolution in the region during the Devonian.

Název v anglickém jazyce

Devonian subduction retreat recorded in the Chinese Altai Orogen: Petro-structural and geochronological constraints from orogenic lower crust migmatite-granite complexes

Popis výsledku anglicky

Crustal extension due to the retreat of subduction system has been assigned as an important mechanism gov-erning the Devonian tectonic evolution of the Chinese Altai Orogen in central Asia. While the extensional regime has been repeatedly inferred from petro-structural (petrographic and structural) records preserved in the orogenic upper crust sedimentary covers and orogenic middle crust schists, such records have rarely been documented in the deep crustal migmatitic and/or magmatic rocks. This gap is filled in this study by applying combined petro-structural analysis in conjunction with zircon and monazite U-Pb geochronology on represen-tative orogenic lower crustal migmatite-granite complexes. These complexes are characterized by the develop-ment of a sub-horizontal foliation associated with extensional melt-filled shear bands. The foliation commonly contains garnet-sillimanite +/- K-feldspar +/- cordierite-bearing metamorphic assemblages that are compatible with a low-pressure/high-temperature thermal regime. In addition, such mineral assemblages are usually found to replace pre-existing middle-pressure/middle-temperature Barrovian-type ones, reflecting a tectonic switch from thickening to extension. New monazite and zircon U-Pb age data, together with regional pre-existing ages, suggest that the sub-horizontal high-temperature foliation formed during a period of 420-390 Ma. Combined with previously published data, our data reinforce that a crustal-scale extensional tectonic regime developed in response to retreating of subduction system governed the geodynamic evolution of the Chinese Altai Orogen during Devonian times. This process led to regional anatexis of the pre-existing Ordovician accretionary wedge complex, facilitated the formation of stabilized and vertically stratified continental crust, and promoted the metallogenic evolution in the region during the Devonian.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GX19-27682X" target="_blank" >GX19-27682X: Hlavní mechanismy periferálního kontinentálního růstu během superkontinentálního cyklu</a><br>

Návaznosti

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

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název periodika

Journal of Asian Earth Sciences

ISSN

1367-9120

e-ISSN

1878-5786

Svazek periodika

244

Číslo periodika v rámci svazku

105540

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

20

Strana od-do

—

Kód UT WoS článku

000993772800001

EID výsledku v databázi Scopus

2-s2.0-85146228627