Detachment folding of partially molten crust in accretionary orogens: A new magma-enhanced vertical mass and heat transfer mechanism

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F17%3A00483167" target="_blank" >RIV/67985530:_____/17:00483167 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/17:00000052 RIV/00216208:11310/17:10370369

Výsledek na webu

<a href="http://dx.doi.org/10.1130/L670.1" target="_blank" >http://dx.doi.org/10.1130/L670.1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1130/L670.1" target="_blank" >10.1130/L670.1</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Detachment folding of partially molten crust in accretionary orogens: A new magma-enhanced vertical mass and heat transfer mechanism

Popis výsledku v původním jazyce

We use structural, petrographic, and geochronological data to examine processes of exhumation of partially molten crust in the Late Devonian-early Carboniferous Chandman dome in the Mongolian tract of the Central Asian Orogenic Belt. The dome is composed of a magmatite-migmatite core and a low-grade metamorphic envelope of early Paleozoic metasediments and Carboniferous clastics. Its tectonic evolution can be divided into three main stages. The oldest fabric is a subhorizontal foliation, S-1, in migmatites that is subparallel to the magmatic foliation in granitoids and to the greenschist facies schistosity in the enveloping metasediments. This event is interpreted as a result of horizontal deep crustal flow at depths of 20-25 km. The S-1 layering was subsequently transposed into a new foliation, S-2, or affected by open to close upright F-2 folds that are locally truncated by steep walls of diatexites, suggesting influx of partially molten crust into fold cores. The shallow-dipping magmatic foliation in granitoids is locally reworked by vertical magmatic to gneissic S-2 fabrics. Syn-S-2 metamorphic assemblages and synkinematic to postkinematic cordierite point to exhumation of the migmatites and granitoids from 20-25 km to similar to 10 km, and concomitant isobaric heating of the surrounding upper crust. New Ar-40/Ar-39 ages of 350-340 Ma from both the high-grade core and the metamorphic mantle overlap with previously published crystallization ages of 360-340 Ma, suggesting that magmatism and cooling in the upper crust are partly synchronous. Late syn-D-2, S-2-parallel leucogranite sheets crosscutting both the magmatic core and the mantling migmatites either exploit S-2 or crosscut horizontal S-1 fabrics. They are interpreted as brittle expulsion of magma during ongoing syn-D-2 exhumation.

Název v anglickém jazyce

Detachment folding of partially molten crust in accretionary orogens: A new magma-enhanced vertical mass and heat transfer mechanism

Popis výsledku anglicky

We use structural, petrographic, and geochronological data to examine processes of exhumation of partially molten crust in the Late Devonian-early Carboniferous Chandman dome in the Mongolian tract of the Central Asian Orogenic Belt. The dome is composed of a magmatite-migmatite core and a low-grade metamorphic envelope of early Paleozoic metasediments and Carboniferous clastics. Its tectonic evolution can be divided into three main stages. The oldest fabric is a subhorizontal foliation, S-1, in migmatites that is subparallel to the magmatic foliation in granitoids and to the greenschist facies schistosity in the enveloping metasediments. This event is interpreted as a result of horizontal deep crustal flow at depths of 20-25 km. The S-1 layering was subsequently transposed into a new foliation, S-2, or affected by open to close upright F-2 folds that are locally truncated by steep walls of diatexites, suggesting influx of partially molten crust into fold cores. The shallow-dipping magmatic foliation in granitoids is locally reworked by vertical magmatic to gneissic S-2 fabrics. Syn-S-2 metamorphic assemblages and synkinematic to postkinematic cordierite point to exhumation of the migmatites and granitoids from 20-25 km to similar to 10 km, and concomitant isobaric heating of the surrounding upper crust. New Ar-40/Ar-39 ages of 350-340 Ma from both the high-grade core and the metamorphic mantle overlap with previously published crystallization ages of 360-340 Ma, suggesting that magmatism and cooling in the upper crust are partly synchronous. Late syn-D-2, S-2-parallel leucogranite sheets crosscutting both the magmatic core and the mantling migmatites either exploit S-2 or crosscut horizontal S-1 fabrics. They are interpreted as brittle expulsion of magma during ongoing syn-D-2 exhumation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Lithosphere

ISSN

1941-8264

e-ISSN

—

Svazek periodika

9

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

21

Strana od-do

889-909

Kód UT WoS článku

000417374300003

EID výsledku v databázi Scopus

2-s2.0-85035132515