Structural and geochronological constraints on Devonian supra-subduction tectonic switching and Permian collisional dynamics in the Chinese Altai, central Asia

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F19%3A00000348" target="_blank" >RIV/00025798:_____/19:00000348 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1029/2018TC005231" target="_blank" >https://doi.org/10.1029/2018TC005231</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2018TC005231" target="_blank" >10.1029/2018TC005231</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Structural and geochronological constraints on Devonian supra-subduction tectonic switching and Permian collisional dynamics in the Chinese Altai, central Asia

Popis výsledku v původním jazyce

Kinematic significance and time scales of geodynamic processes forming the Altai Orogenic Belt are addressed through structural and petrological analysis combined with zircon and monazite geochronology. The study area is composed of orogenic lower crust represented by a Devonian migmatite‐magmatite complex and orogenic middle and upper crust formed by an amphibolite‐facies Ordovician sedimentary sequence and a weakly to unmetamorphosed Devonian volcano‐sedimentary cover, respectively. The orogenic lower and middle crust were first affected by moderate thickening, which formed subhorizontal Barrovian metamorphic schistosity. This fabric was reworked by deep crustal melting and intrusion of granite sheets during horizontal extension at 400–380 Ma. Soon after, this horizontal fabric wasaffected by NW‐SE shortening generating crustal‐scale upright folding associated with subvertical flow of still partially molten orogenic lower crust. During this event, the orogenic lower and middle crust weretightly juxtaposed with upper crustal sedimentary rocks. The last event was related with a NE‐SW oriented convergence resulting in large‐scale folding and megafold interference pattern in the Permian at 280–273 Ma. Combined with existing regional data, our results allow proposing a Devonian tectonic switching from compression to extension and back to compression, as a response to variations of subduction dynamics between slab advance and retreat in a Pacific‐type suprasubduction system. The Permian folding was associated with the progressive northward exhumation of thermally softened crust. This tectonic evolution is in response to the indentation of the rigid Junggar arc domain into the weak Altai wedge.

Název v anglickém jazyce

Structural and geochronological constraints on Devonian supra-subduction tectonic switching and Permian collisional dynamics in the Chinese Altai, central Asia

Popis výsledku anglicky

Kinematic significance and time scales of geodynamic processes forming the Altai Orogenic Belt are addressed through structural and petrological analysis combined with zircon and monazite geochronology. The study area is composed of orogenic lower crust represented by a Devonian migmatite‐magmatite complex and orogenic middle and upper crust formed by an amphibolite‐facies Ordovician sedimentary sequence and a weakly to unmetamorphosed Devonian volcano‐sedimentary cover, respectively. The orogenic lower and middle crust were first affected by moderate thickening, which formed subhorizontal Barrovian metamorphic schistosity. This fabric was reworked by deep crustal melting and intrusion of granite sheets during horizontal extension at 400–380 Ma. Soon after, this horizontal fabric wasaffected by NW‐SE shortening generating crustal‐scale upright folding associated with subvertical flow of still partially molten orogenic lower crust. During this event, the orogenic lower and middle crust weretightly juxtaposed with upper crustal sedimentary rocks. The last event was related with a NE‐SW oriented convergence resulting in large‐scale folding and megafold interference pattern in the Permian at 280–273 Ma. Combined with existing regional data, our results allow proposing a Devonian tectonic switching from compression to extension and back to compression, as a response to variations of subduction dynamics between slab advance and retreat in a Pacific‐type suprasubduction system. The Permian folding was associated with the progressive northward exhumation of thermally softened crust. This tectonic evolution is in response to the indentation of the rigid Junggar arc domain into the weak Altai wedge.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA17-17540S" target="_blank" >GA17-17540S: Kontrastní mechanizmy růstu superkontinentu Pangea: nový pohled na tvorbu kontinentální kůry</a><br>

Návaznosti

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

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Tectonics

ISSN

0278-7407

e-ISSN

—

Svazek periodika

38

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

28

Strana od-do

253-280

Kód UT WoS článku

000458959800014

EID výsledku v databázi Scopus

2-s2.0-85060736784