Modes and geometry of crustal-scale detachment folding in hot orogens – insights from physical modeling

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F22%3A00562546" target="_blank" >RIV/67985530:_____/22:00562546 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/22:00000200 RIV/00216208:11310/22:10457196

Výsledek na webu

<a href="https://www.frontiersin.org/articles/10.3389/feart.2022.965497/full" target="_blank" >https://www.frontiersin.org/articles/10.3389/feart.2022.965497/full</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3389/feart.2022.965497" target="_blank" >10.3389/feart.2022.965497</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Modes and geometry of crustal-scale detachment folding in hot orogens – insights from physical modeling

Popis výsledku v původním jazyce

Detachment folding can be defined as the displacement and buckling of a competent layer above a rheologically weak horizon during tectonic shortening, frequently addressed in the context of salt tectonics. More recent studies have focused on influence of detachments in large-scale lithospheric deformation where the detachment horizon is represented by partially molten lower crust. This study addresses the geometric, kinematic and dynamic behavior of crustal-scale detachment folds using heated paraffin wax as an analogue for partially molten lower crust. Various thermal and shortening rate scenarios were tested in order to characterize deformation patterns within hot orogens in general, and to find an appropriate range of temperature gradients and shortening rates for the detachment folding regime. Five different regimes of lower crustal deformation were identified: 1. Homogeneous thickening or bulging, 2. Short-wavelength folding, 3. Development of diapir-shape folds or ductile faults, 4. Detachment folding and 5. Formation of lower crustal finger-like protrusions. Models are compared to various natural prototypes worldwide, in particular a series of metamorphic domes in the Central Asian Orogenic Belt (CAOB). Detailed analysis of the kinematic-dynamic evolution of the detachment folding scenario revealed an asymmetrical evolution of the folds associated with rotation of the limbs, as well as flexural flow of the lower weak mushy crust around the molten core. Pressure gradients in the fold cores saturated by melt controlled the sequential injections and outflows of partially/molten material between folds' cores and the melt source layer at the base of the system. This resulted in accumulation of melt in the foreland of the accretionary zone, with higher melt absorption potential for newly developed folds. These observations may have significant implications for the development of pseudo-symmetrical metamorphic domes in the CAOB.

Název v anglickém jazyce

Modes and geometry of crustal-scale detachment folding in hot orogens – insights from physical modeling

Popis výsledku anglicky

Detachment folding can be defined as the displacement and buckling of a competent layer above a rheologically weak horizon during tectonic shortening, frequently addressed in the context of salt tectonics. More recent studies have focused on influence of detachments in large-scale lithospheric deformation where the detachment horizon is represented by partially molten lower crust. This study addresses the geometric, kinematic and dynamic behavior of crustal-scale detachment folds using heated paraffin wax as an analogue for partially molten lower crust. Various thermal and shortening rate scenarios were tested in order to characterize deformation patterns within hot orogens in general, and to find an appropriate range of temperature gradients and shortening rates for the detachment folding regime. Five different regimes of lower crustal deformation were identified: 1. Homogeneous thickening or bulging, 2. Short-wavelength folding, 3. Development of diapir-shape folds or ductile faults, 4. Detachment folding and 5. Formation of lower crustal finger-like protrusions. Models are compared to various natural prototypes worldwide, in particular a series of metamorphic domes in the Central Asian Orogenic Belt (CAOB). Detailed analysis of the kinematic-dynamic evolution of the detachment folding scenario revealed an asymmetrical evolution of the folds associated with rotation of the limbs, as well as flexural flow of the lower weak mushy crust around the molten core. Pressure gradients in the fold cores saturated by melt controlled the sequential injections and outflows of partially/molten material between folds' cores and the melt source layer at the base of the system. This resulted in accumulation of melt in the foreland of the accretionary zone, with higher melt absorption potential for newly developed folds. These observations may have significant implications for the development of pseudo-symmetrical metamorphic domes in the CAOB.

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

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Frontiers in Earth Science

ISSN

2296-6463

e-ISSN

2296-6463

Svazek periodika

10

Číslo periodika v rámci svazku

November

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

20

Strana od-do

965497

Kód UT WoS článku

000889087300001

EID výsledku v databázi Scopus

2-s2.0-85142303544